01972nas a2200181 4500008004100000022001400041245015400055210006900209260012500278300001100403490000800414520116400422100001601586700002101602700002001623700001801643856012901661 2013 eng d a0021-960600aCorrelation between the variation in observed melting temperatures and structural motifs of the global minima of gallium clusters: an ab initio study0 aCorrelation between the variation in observed melting temperatur aCIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USAbAMER INST PHYSICScJAN a0143030 v1383 a

We have investigated the correlation between the variation in the melting temperature and the growth pattern of small positively charged gallium clusters. Significant shift in the melting temperatures was observed for a change of only few atoms in the size of the cluster. Clusters with size between 31-42 atoms melt between 500-600 K whereas those with 46-48 atoms melt around 800 K. Density functional theory based first principles simulations have been carried out on Ga-n(+) clusters with n = 31, ... , 48. At least 150 geometry optimizations have been performed towards the search for the global minima for each size resulting in about 3000 geometry optimizations. For gallium clusters in this size range, the emergence of spherical structures as the ground state leads to higher melting temperature. The well-separated core and surface shells in these clusters delay isomerization, which results in the enhanced stability of these clusters at elevated temperatures. The observed variation in the melting temperature of these clusters therefore has a structural origin. (C) 2013 American Institute of Physics. [http://dx.doi.org/10.1063/1.4772470]

1 aSusan, Anju1 aKibey, Aniruddha1 aKaware, Vaibhav1 aJoshi, Kavita uhttp://library.ncl.res.in/content/correlation-between-variation-observed-melting-temperatures-and-structural-motifs-global-002056nas a2200217 4500008004100000245008000041210006900121260011700190300003200307490000900339520122200348100001701570700002201587700002501609700002001634700002001654700002201674700001801696700001701714856010701731 2014 eng d00aDesign and engineering of organic molecules for customizable terahertz tags0 aDesign and engineering of organic molecules for customizable ter aSan Francisco, CAbSPIE-Int Soc Optical Engineering, 1000 20th ST, PO Box 10, Bellingham, WA 98227-0010 USAcFEB aArticle Number: UNSP 89850P0 v89853 a

Terahertz (THz) frequency band lies between the microwave and infrared region of the electromagnetic spectrum. Molecules having strong resonances in this frequency range are ideal for realizing "Terahertz tags" which can be easily incorporated into various materials. THz spectroscopy of molecules, especially at frequencies below 10 THz, provides valuable information on the low frequency vibrational modes, viz. intermolecular vibrational modes, hydrogen bond stretching, torsional vibrations in several chemical and biological compounds. So far there have been very few attempts to engineer molecules which can demonstrate customizable resonances in the THz frequency region. In this paper, Diamidopyridine (DAP) based molecules are used as a model system to demonstrate engineering of THz resonances (< 10 THz) by fine-tuning the molecular mass and bond strengths. Density Functional Theory (DFT) simulations have been carried out to explain the origin of THz resonances and factors contributing to the shift in resonances due to the addition of various functional groups. The design approach presented here can be easily extended to engineer various organic molecules suitable for THz tags application.

1 aRay, Shaumik1 aDash, Jyotirmayee1 aNallappan, Kathirvel1 aKaware, Vaibhav1 aBasutkar, Nitin1 aAmbade, Ashootosh1 aJoshi, Kavita1 aPesala, Bala uhttp://library.ncl.res.in/content/design-and-engineering-organic-molecules-customizable-terahertz-tags02182nas a2200157 4500008004100000022001400041245013700055210006900192260012500261300001100386490000800397520145400405100001601859700001801875856013101893 2014 eng d a0021-960600aRationalizing the role of structural motif and underlying electronic structure in the finite temperature behavior of atomic clusters0 aRationalizing the role of structural motif and underlying electr aCIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USAbAMER INST PHYSICScAPR a1543070 v1403 a

Melting in finite size systems is an interesting but complex phenomenon. Many factors affect melting and owing to their interdependencies it is a challenging task to rationalize their roles in the phase transition. In this work, we demonstrate how structural motif of the ground state influences melting transition in small clusters. Here, we report a case with clusters of aluminum and gallium having same number of atoms, valence electrons, and similar structural motif of the ground state but drastically different melting temperatures. We have employed Born-Oppenheimer molecular dynamics to simulate the solid-like to liquid-like transition in these clusters. Our simulations have reproduced the experimental trends fairly well. Further, the detailed analysis of isomers has brought out the role of the ground state structure and underlying electronic structure in the finite temperature behavior of these clusters. For both clusters, isomers accessible before cluster melts have striking similarities and does have strong influence of the structural motif of the ground state. Further, the shape of the heat capacity curve is similar in both the cases but the transition is more spread over for Al-36 which is consistent with the observed isomerization pattern. Our simulations also suggest a way to characterize transition region on the basis of accessibility of the ground state at a specific temperature. (C) 2014 AIP Publishing LLC.

1 aSusan, Anju1 aJoshi, Kavita uhttp://library.ncl.res.in/content/rationalizing-role-structural-motif-and-underlying-electronic-structure-finite-temperature-001785nas a2200157 4500008004100000022001400041245006900055210006800124260012500192300002300317490000800340520114900348100002001497700001801517856009201535 2014 eng d a0021-960600aScaling up the shape: a novel growth pattern of gallium clusters0 aScaling up the shape a novel growth pattern of gallium clusters aCIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USAbAMER INST PHYSICScAUG aArticle No. 0543080 v1413 a

Putative global minima for Ga+N clusters with size ``N'' ranging from 49 to 70 are found by employing the Kohn-Sham formulation of the density functional theory, and their evolution is described and discussed in detail. We have discovered a unique growth pattern in these clusters, all of which are hollow core-shell structures. They evolve with size from one spherical core-shell to the next spherical core-shell structure mediated by prolate geometries, with an increase in overall diameter of the core, as well as the shell, without putting on new layers of atoms. We also present a complete picture of bonding in gallium clusters by critically analyzing the molecular orbitals, the electron localization function, and Bader charges. Bonding in these clusters is a mixture of metallic and covalent type that leans towards covalency, accompanied by marginal charge transfer from the surface to the core. Most molecular orbitals of Ga clusters are non-jellium type. Covalency of bonding is supported by a wide localization window of electron localization function, and joining of its basins along the bonds. (C) 2014 AIP Publishing LLC.

1 aKaware, Vaibhav1 aJoshi, Kavita uhttp://library.ncl.res.in/content/scaling-shape-novel-growth-pattern-gallium-clusters-001746nas a2200169 4500008004100000022001400041245007300055210006700128260007100195300001600266490000800282520113200290100001601422700002001438700001801458856010001476 2015 eng d a1932-744700aMultifaceted thermodynamics of Pb-n (n=16-24) clusters: a case study0 aMultifaceted thermodynamics of Pbn n1624 clusters a case study a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcOCT a23698-237070 v1193 a

Thermodynamic response of small clusters is a challenging area of exploration, both experimentally and theoretically. In this article, we study the thermodynamic behavior of small Pb clusters (size 16-24) using Born-Oppenheimer molecular dynamics. A new ground state structure is reported for Pb-20. Except for Pb-21, all clusters fragment at temperatures above T-m[bulk] and show no signs of melting. Characteristic behavior like restricted diffusion and solid solid transition is discussed in detail. Variation in the isomerization temperature of these clusters is explained using the bond length analysis. Root mean square bond length fluctuations (delta(rms)) along with distribution of atoms about center of mass of the cluster as a function of time and distance-energy (DE) plots are used to bring out the essential features of Pb cluster thermodynamics. Analysis carried out using these parameters, and their interpretation regarding state of the system, are discussed in detail. We highlight that it is not possible to define ``liquid state'' for these small clusters, in the conventional frame of understanding.

1 aSusan, Anju1 aKaware, Vaibhav1 aJoshi, Kavita uhttp://library.ncl.res.in/content/multifaceted-thermodynamics-pb-n-n16-24-clusters-case-study-101038nas a2200121 4500008004100000245005700041210005700098260000800155520062700163100002000790700001800810856008800828 2015 eng d00aPartial ionic bonding in homogeneous sodium clusters0 aPartial ionic bonding in homogeneous sodium clusters cAPR3 a

In this work, we report an interesting observation of partial ionic bonding due to charge transfer in homogeneous sodium clusters. The charge transfer causes the electronic charge to accumulate on the surface, and the resulting charges on atoms range between +0.4 to -1.0 |e^-|. We also demonstrate that this disparity among effective charges on atoms is geometry dependent, such that atoms experiencing similar surrounding, have equal effective charge. It is speculated that this phenomenon will occur among other homogeneous clusters as well, and its extent will be defined by the valence electron delocalization.

1 aKaware, Vaibhav1 aJoshi, Kavita uhttp://library.ncl.res.in/content/partial-ionic-bonding-homogeneous-sodium-clusters02540nas a2200229 4500008004100000022001400041245013000055210006900185260011000254300001600364490000600380520161200386100002801998700002002026700002302046700002202069700002302091700001802114700002602132700002402158856012802182 2015 eng d a2046-206900aPt-nanoparticle functionalized carbon nano-onions for ultra-high energy supercapacitors and enhanced field emission behaviour0 aPtnanoparticle functionalized carbon nanoonions for ultrahigh en aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcSEP a80990-809970 v53 a

In the present work, we have investigated the charge storage capacitive response and field emission behaviour of platinum (Pt) nanoparticles decorated on carbon nano onions (CNOs) and compared them with those of pristine carbon nano onions. The specific capacitance observed for Pt-CNOs is 342.5 F g(-1), about six times higher than that of pristine CNOs, at a scan rate of 100 mV s(-1). The decoration with Pt nanoparticles, without any binder or polymer separator on the CNO, leading to enhanced supercapacitance is due to easy accessibility of Na2SO4 electrolyte in the active material. The Density Functional Theory (DFT) calculations of these systems reveal enhancement in the Density of States (DOS) near the Fermi energy (E-F) on account of platinum decoration on the CNOs. Furthermore, the field emission current density of similar to 0.63 mA cm(-2) has been achieved from the Pt-CNOs emitter at an applied electric field of similar to 4.5 V mu m(-1) and from the pristine CNOs sample current density of similar to 0.4 mA cm(-2) has been achieved at an applied electric field of similar to 6.6 V mu m(-1). The observed enhanced field emission behavior has been attributed to the improved electrical conductivity and increased emitting sites of the Pt-CNO emitter. The field emission current stability of the Pt-CNO emitter over a longer duration is found to be good. The observed results imply multifunctional potential of Pt-CNOs, as supercapacitor material in various next generation hybrid energy storage devices, and field emitters for next generation vacuum nano/microelectronic devices.

1 aSuryawanshi, Sachin, R.1 aKaware, Vaibhav1 aChakravarty, Disha1 aWalke, Pravin, S.1 aMore, Mahendra, A.1 aJoshi, Kavita1 aRout, Chandra, Sekhar1 aLate, Dattatray, J. uhttp://library.ncl.res.in/content/pt-nanoparticle-functionalized-carbon-nano-onions-ultra-high-energy-supercapacitors-and-002650nas a2200241 4500008004100000022001400041245011100055210006900166260007100235300001400306490000800320520176800328100002202096700001802118700002502136700002002161700002402181700002402205700002602229700001802255700001702273856011802290 2015 eng d a1089-563900aTerahertz spectroscopy and solid-state density functional theory calculations of cyanobenzaldehyde isomers0 aTerahertz spectroscopy and solidstate density functional theory  a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcJUL a7991-79990 v1193 a

Spectral signatures in the terahertz (THz) frequency region are mainly due to bulk vibrations of the molecules. These resonances are highly sensitive to the relative position of atoms in a molecule as well as the crystal packing arrangement. To understand the variation of THz resonances, THz spectra (2-10 THz) of three structural isomers: 2-, 3-, and 4-cyanobenzaldehyde have been studied. THz spectra obtained from Fourier transform infrared (FTIR) spectrometry of these isomers show that the resonances are distinctly different especially below 5 THz. For understanding the intermolecular interactions due to hydrogen bonds, four molecule cluster simulations of each of the isomers have been carried out using the B3LYP density functional with the 6-31G(d,p) basis set in Gaussian09 software and the compliance constants are obtained. However, to understand the exact reason behind the observed resonances, simulation of each isomer considering the full crystal structure is essential. The crystal structure of each isomer has been determined using X-ray diffraction (XRD) analysis for carrying out crystal structure simulations. Density functional theory (DFT) simulations using CRYSTAL14 software, utilizing the hybrid density functional B3LYP, have been carried out to understand the vibrational modes. The bond lengths and bond angles from the optimized structures are compared with the XRD results in terms of root-mean-square-deviation (RMSD) values. Very low RMSD values confirm the overall accuracy of the results. The simulations are able to predict most of the spectral features exhibited by the isomers. The results show that low frequency modes (<3 THz) are mediated through hydrogen bonds and are dominated by intermolecular vibrations.

1 aDash, Jyotirmayee1 aRay, Shaurnik1 aNallappan, Kathirvel1 aKaware, Vaibhav1 aBasutkar, Nitin, B.1 aGonnade, Rajesh, G.1 aAmbade, Ashootosh, V.1 aJoshi, Kavita1 aPesala, Bala uhttp://library.ncl.res.in/content/terahertz-spectroscopy-and-solid-state-density-functional-theory-calculations-001956nas a2200229 4500008004100000022001400041245010000055210006900155260000800224300001200232490000800244520121400252653001201466653000801478653001801486653001601504653002401520100002001544700001901564700001801583856012501601 2019 eng d a0039-602800aNature of electrophilic oxygen: insights from periodic density functional theory investigations0 aNature of electrophilic oxygen insights from periodic density fu cJAN a188-1950 v6793 a

Increasing demand of ethylene oxide and the cost of versatile chemical ethene has been a driving force for understanding mechanism of epoxidation to develop highly selective catalytic process. Direct epoxidation is a proposed mechanism which in theory provides 100% selectivity. A key aspect of this mechanism is an electrophilic oxygen (O-ele) species forming on the Ag surface. In the past two and half decades, large number of theoretical and experimental investigations have tried to elucidate formation of O-ele, on Ag surface with little success. Equipped with this rich literature on Ag-O interactions, we investigate the same using periodic DFT calculations to further understand how silver surface and oxygen interact with each other from a chemical standpoint. Based on energetics, Lowdin charges, topologies and pdos data described in this study, we scrutinize the established notions of O-ele. Our study provides no evidence in support of O-ele, being an atomic species nor a diatomic molecular species. In fact, a triatomic molecular species described in this work bears multiple signatures which are very convincing evidence for considering it as the most sought for electrophilic entity.

10aAg(100)10aDFT10aElectrophilic10aepoxidation10aNucleophilic oxygen1 aKenge, Nivedita1 aPitale, Sameer1 aJoshi, Kavita uhttp://library.ncl.res.in/content/nature-electrophilic-oxygen-insights-periodic-density-functional-theory-investigations02351nas a2200205 4500008004100000022001400041245017900055210006900234260000900303300001400312490000600326520155500332100002401887700001801911700002301929700002301952700001801975700002101993856013102014 2020 eng d a2516-023000aAgro-waste extracted cellulose supported silver phosphate nanostructures as a green photocatalyst for improved photodegradation of RhB dye and industrial fertilizer effluents0 aAgrowaste extracted cellulose supported silver phosphate nanostr cJUL  a2870-28840 v23 a

The efficiency and reusability of photocatalysts are the dominant factors for their pragmatic use. The visible light induced semiconductor silver phosphate is a superior photocatalyst effective under visible light but its stability is still an undiscussed issue. To overcome this stability issue in this present manuscript, eco-friendly agro-waste extracted cellulose supported silver phosphate nanostructures have been designed for the first time through a simple chemical process. At first, silver phosphate nanostructures were synthesized by the co-precipitation method. Then, different weights of cellulose were added to the silver nitrate solution to form cellulose supported silver phosphate nanostructures. The photodegradation efficiency for each weight ratio was examined in which the photocatalyst Ag-8 nanostructures showed a high rate (0.024 min(-1)) for degradation of Rhodamine B (RhB) using a low intensity tungsten bulb. Real sample analysis has also been carried out using this photocatalyst for the degradation of industrial fertilizer effluents. The degradation rate of all the nanostructures was found to be high in comparison to pristine silver phosphate as well as the extracted bare cellulose. The photocatalytic activity is enhanced because of the participation of cellulose as a support which makes an interface for silver phosphate and assists it in delaying the charge recombination period under visible light. To understand the photochemical reaction of electrons and holes, scavenger studies were also performed.

1 aDwivedi, Pravin, K.1 aNair, Aathira1 aMehare, Rupali, S.1 aChaturvedi, Vikash1 aJoshi, Kavita1 aShelke, Manjusha uhttp://library.ncl.res.in/content/agro-waste-extracted-cellulose-supported-silver-phosphate-nanostructures-green-photocatalyst02244nas a2200205 4500008004100000022001400041245022100055210006900276260000900345300001400354490000600368520142800374100002401802700001801826700002301844700002301867700001801890700000501908856012501913 2020 eng d a2516-023000aExperimental and theoretical investigations of the effect of heteroatom-doped carbon microsphere supports on the stability and storage capacity of nano-Co3O4 conversion anodes for application in lithium-ion batteries0 aExperimental and theoretical investigations of the effect of het cJUL  a2914-29240 v23 a

Conversion-type anode materials have been intensely studied for application in Li-ion batteries (LIBs) due to their potentially higher capacities than current graphite-based anodes. This work reports the development of a high-capacity and stable anode from a nanocomposite of N and S co-doped carbon spheres (NSCSs) with Co3O4 (NSCS-Co3O4). A hydrothermal reaction of saccharose withl-cysteine was carried out, followed by its carbonization. CSs when used as supports for conversion-type materials provide efficient electron/ion transfer channels, enhancing the overall electrochemical performance of the electrodes. Additionally, the heteroatoms doped in a carbon matrix alter the electronic properties, often increasing the reactivity of the carbon surface, and they are reported to be effective for anchoring metal oxide nanoparticles. Consequently, the NSCS-Co3O4 nanocomposites developed in this work exhibit enhanced and stable reversible specific capacity over several cycles. Stable cycling behavior was observed at 1 A g(-1)with 1285 mA h g(-1) of specific capacity retained after 350 cycles along with more than 99% of coulombic efficiency. This material shows excellent rate capability with a specific capacity of 745 mA h g(-1) retained even at a high current density of 5 A g(-1). Detailed DFT-based calculations revealed the role of doped supports in controlling the volume expansion upon lithiation.

1 aDwivedi, Pravin, K.1 aNair, Aathira1 aMehare, Rupali, S.1 aChaturvedi, Vikash1 aJoshi, Kavita1 a uhttp://library.ncl.res.in/content/experimental-and-theoretical-investigations-effect-heteroatom-doped-carbon-microsphere02042nas a2200265 4500008004100000022001400041245007100055210006900126260000800195300001100203490000800214520127000222653000801492653000901500653002901509653001201538100001801550700002001568700002001588700002501608700001701633700001301650700001801663856009501681 2020 eng d a0169-433200aMixed metal oxide: a new class of catalyst for methanol activation0 aMixed metal oxide a new class of catalyst for methanol activatio cDEC a1474490 v5343 a

In this work, we propose a mixed metal oxide as a catalyst and demonstrate it's ability to not only activate the MeOH molecule upon adsorption but also dissociate O-H and one of it's C-H bonds. MeOH activation is compared on two prominent facets of ZnAl(2)O(4 )viz. (2 2 0) and (31 1). While spontaneous O-H bond dissociation is observed on both facets, C-H bond dissociates only on the (3 1 1) surface. Multiple factors like atomic arrangement and steps on the surface, coordination of surface atoms, and their effective charges have a combined effect on MeOH activation. The (3 1 1) surface offers higher catalytic activity in comparison with (2 2 0) surface. Having a stepped surface, availability of multiple sites, and variation in the charge distribution are some of the reasons for better catalytic performance of (3 1 1) facet. Effect of orientation of MeOH with respect to the surface adds both, information and complexity to the problem. Observations pertinent to understanding this effect are also reported. A detailed analysis of atomic arrangement on the two surfaces provides a rationale as to why MeOH gets dissociated spontaneously on the mixed metal oxide. The promising results reported here opens up a new class of catalyst for research.

10aDFT10aMeOH10aSpontaneous dissociation10aZnAl2O41 aMehta, Shweta1 aAgarwal, Sheena1 aKenge, Nivedita1 aMekala, Siva, Prasad1 aPatil, Vipul1 aRaja, T.1 aJoshi, Kavita uhttp://library.ncl.res.in/content/mixed-metal-oxide-new-class-catalyst-methanol-activation02294nas a2200169 4500008004100000022001400041245010700055210006900162260000900231300001400240490000700254520167800261100002001939700001801959700001801977856012901995 2020 eng d a1144-054600aUnderstanding the ML black box with simple descriptors to predict cluster-adsorbate interaction energy0 aUnderstanding the ML black box with simple descriptors to predic cMAY  a8545-85530 v443 a

Density functional theory (DFT) is currently one of the most accurate and yet practical theories used to gain insight into the properties of materials. Although successful, the computational cost required is still the main hurdle even today. In recent years, there has been a trend of combining DFT with Machine Learning (ML) to reduce the computational cost without compromising accuracy. Finding the right set of descriptors that are simple to understand in terms of giving insights about the problem at hand, lies at the heart of any ML problem. In this work, we demonstrate the use of nearest neighbor (NN) distances as descriptors to predict the interaction energy between the cluster and an adsorbate. The model is trained over a size range of 5 to 75 atom clusters. When the training and testing is carried out on mutually exclusive cluster sizes, the mean absolute error (MAE) in predicting the interaction energy is similar to 0.24 eV. MAE reduces to 0.1 eV when testing and training sets include information from the complete range. Furthermore, when the same set of descriptors are tested over individual sizes, the MAE further reduces to similar to 0.05 eV. We bring out the correlation between dispersion in the nearest neighbor distances and variation in MAE for individual sizes. Our detailed and extensive DFT calculations provide a rationale as to why nearest neighbor distances work so well. Finally, we also demonstrate the transferability of the ML model by applying the same recipe of descriptors to systems of different elements like (Na-10), bimetallic systems (Al6Ga6, Li4Sn6, and Au40Cu40) and also different adsorbates (N-2, O-2, and CO).

1 aAgarwal, Sheena1 aMehta, Shweta1 aJoshi, Kavita uhttp://library.ncl.res.in/content/understanding-ml-black-box-simple-descriptors-predict-cluster-adsorbate-interaction-energy01727nas a2200229 4500008004100000245013600041210006900177260000800246300001600254490000700270520092300277100002201200700001801222700001801240700001601258700002001274700001901294700001801313700001801331700002301349856012501372 2021 eng d00aCopolymers of bipyridinium and metal (Zn & Ni) porphyrin derivatives; theoretical insights and electrochemical activity towards CO20 aCopolymers of bipyridinium and metal Zn Ni porphyrin derivatives cJUN a19844-198550 v113 aThis study reports the electropolymerization of novel keto functionalized octaethyl metal porphyrins (Zn2+ and Ni2+) in the presence of 4,4 `-bipyridine (4,4 `-bpy) as a bridging nucleophile. The polymer films were characterized by electrochemical, spectroscopic (UV-Vis, XPS, FT-IR and Raman spectroscopy) and imaging (AFM and SEM) techniques. The absorption and electronic spectra confirm the presence of both porphyrin and 4,4 `-bipyridine units in the film. The surface morphology reveals homogeneous film deposition with average roughness values of approx. 8 nm. The theoretical studies performed offered insights into the interplay of different metal centres (Zn2+ and Ni2+) and the keto functionality of the porphyrin unit in the formation of copolymer films. The electrochemical interaction of polymer films with CO2 suggests a reversible trap and release of CO2 with low energy barriers for both the polymers.1 aKochrekar, Sachin1 aKalekar, Ajit1 aMehta, Shweta1 aDamlin, Pia1 aSalomaki, Mikko1 aGranroth, Sari1 aMeltola, Niko1 aJoshi, Kavita1 aKvarnstrom, Carita uhttp://library.ncl.res.in/content/copolymers-bipyridinium-and-metal-zn-ni-porphyrin-derivatives-theoretical-insights-and02618nas a2200193 4500008004100000022001400041245016300055210006900218260000900287300001600296490000700312520188200319100001702201700002002218700001902238700001802257700002102275856012802296 2021 eng d a1463-907600aDART: deep learning enabled topological interaction model for energy prediction of metal clusters and its application in identifying unique low energy isomers0 aDART deep learning enabled topological interaction model for ene cOCT  a21995-220030 v233 aRecently, machine learning (ML) has proven to yield fast and accurate predictions of chemical properties to accelerate the discovery of novel molecules and materials. The majority of the work is on organic molecules, and much more work needs to be done for inorganic molecules, especially clusters. In the present work, we introduce a simple topological atomic descriptor called TAD, which encodes chemical environment information of each atom in the cluster. TAD is a simple and interpretable descriptor where each value represents the atom count in three shells. We also introduce the DART deep learning enabled topological interaction model, which uses TAD as a feature vector to predict energies of metal clusters, in our case gallium clusters with sizes ranging from 31 to 70 atoms. The DART model is designed based on the principle that the energy is a function of atomic interactions and allows us to model these complex atomic interactions to predict the energy. We further introduce a new dataset called GNC_31-70, which comprises structures and DFT optimized energies of gallium clusters with sizes ranging from 31 to 70 atoms. We show how DART can be used to accelerate the process of identification of low energy structures without geometry optimization. Albeit using a topological descriptor, DART achieves a mean absolute error (MAE) of 3.59 kcal mol(-1) (0.15 eV) on the test set. We also show that our model can distinguish core and surface atoms in the Ga-70 cluster, which the model has never encountered earlier. Finally, we demonstrate the transferability of the DART model by predicting energies for about 6k unseen configurations picked up from molecular dynamics (MD) data for three cluster sizes (46, 57, and 60) within seconds. The DART model was able to reduce the load on DFT optimizations while identifying unique low energy structures from MD data.1 aModee, Rohit1 aAgarwal, Sheena1 aVerma, Ashwini1 aJoshi, Kavita1 aPriyakumar, Deva uhttp://library.ncl.res.in/content/dart-deep-learning-enabled-topological-interaction-model-energy-prediction-metal-clusters01901nas a2200193 4500008004100000022001400041245015300055210006900208260000900277300001400286490000800300520117000308100002401478700002001502700002101522700001801543700003001561856011601591 2021 eng d a1932-744700aDisordered but efficient: understanding the role of structure and composition of the Co-Pt alloy on the electrocatalytic methanol oxidation reaction0 aDisordered but efficient understanding the role of structure and cAPR  a7611-76240 v1253 a

A systematic investigation of the electrocatalytic Methanol Oxidation Reaction (MOR) was carried out using a model Co:Pt alloy system with different compositions and structural arrangements of the Co and Pt atoms. The structural variations with the same alloy composition included those with disordered arrangement of Co and Pt atoms in a face-centered cubic (fcc) lattice and ordered arrangements in face-centered tetragonal (fct) lattices. Our investigations clearly show that structures with disordered arrangements with Co:Pt atomic ratios near to 1:1 display better electrocatalytic efficiencies even when compared to pure Pt. These experimental findings were then rationalized by means of Density Functional Theory (DFT) calculations. Electronic level signatures in terms of charge transfer and relative shift in the peaks of the d band for surface metal atoms are proposed to be the reasons for the superior catalytic activity of a particular composition over the others. An increase in the number of inequivalent sites for methanol adsorption in disordered systems appears to result in better catalytic performance in comparison with ordered systems.

1 aDalavi, Shankar, B.1 aAgarwal, Sheena1 aDeshpande, Pooja1 aJoshi, Kavita1 aPrasad, Bhagavatula L. V. uhttp://library.ncl.res.in/content/disordered-efficient-understanding-role-structure-and-composition-co-pt-alloy01732nas a2200169 4500008004100000022001400041245010900055210006900164260000900233300001000242490000700252520112200259100001701381700002001398700001801418856012601436 2021 eng d a1144-054600aLowering the C-H bond activation barrier of methane by means of SAC@Cu(111): periodic DFT investigations0 aLowering the CH bond activation barrier of methane by means of S cDEC  a70-740 v463 aMethane has long captured the world's attention for being the simplest yet one of the most notorious hydrocarbons. Exploring its potential to be converted into value-added products has raised compelling interest. In the present work, we have studied the efficiency of single-atom catalysts (SACs) for methane activation employing density functional theory (DFT). The climbing image-nudged elastic band (CI-NEB) method is used in tandem with the improved dimer (ID) method to determine the minimum energy pathway for the first C-H bond dissociation of methane. Our study reported that the transition-metal doped Cu(111) surfaces enhance the adsorption, activate the C-H bond, and reduce the activation barrier for first C-H bond cleavage of methane. The results suggest Ru-/Co-/Rh-doped Cu(111) as promising candidates for methane activation with a minimal activation barrier and a less endothermic reaction. For these SACs, the calculated activation barriers for the first C-H bond cleavage are 0.17 eV, 0.24 eV, and 0.26 eV respectively, which is substantially lower than 1.13 eV, the activation barrier for Cu(111).1 aBhati, Meema1 aDhumal, Jignesh1 aJoshi, Kavita uhttp://library.ncl.res.in/content/lowering-c-h-bond-activation-barrier-methane-means-saccu111-periodic-dft-investigations02063nas a2200205 4500008004100000022001400041245010300055210006900158260000800227300001100235490000800246520139700254653000801651653000901659653002501668653000801693100001801701700001801719856012001737 2022 eng d a0169-433200aFrom molecular adsorption to decomposition of methanol on various ZnO facets: a periodic DFT study0 aFrom molecular adsorption to decomposition of methanol on variou cNOV a1541500 v6023 a

Methanol is an interesting and important molecule to study because of its potential to replace existing fuels. It is also a prominent hydrogen source which can be used to generate hydrogen in-situ. ZnO is widely used as catalyst in synthesis of methanol from CO2 at industrial scale. In this work, we demonstrate that the same catalyst could be used for MeOH decomposition. We have investigated interaction of methanol with various flat and stepped facets of ZnO by employing Density Functional Theory (DFT). Two flat [(10(1)overbar 0) and (11(2)overbar 0)] and two stepped [(10(1)overbar 3) and (11(2)overbar 2)] facets are studied in detail for methanol adsorption. Chemisorption of MeOH with varying strength is common to all four facets. Most importantly spontaneous dissociation of O-H bond of methanol is observed on all facets except (11(2)overbar 0). Our DFT calculations reveal that molecular adsorption is favored on flat facets, while dissociation is favored on step facets. Also, (10(1)overbar 0) facet undergoes substantial reconstruction upon MeOH adsorption. Activation of C-H bond along with strengthening of C-O bond on ZnO facets suggest partial oxidation of methanol. With our DFT investigations, we dig deeper into the underlying electronic structure of various facets of ZnO and provide rationale for the observed facet dependent interaction of ZnO with MeOH.

10aDFT10aMeOH10aSurface interactions10aZnO1 aMehta, Shweta1 aJoshi, Kavita uhttp://library.ncl.res.in/content/molecular-adsorption-decomposition-methanol-various-zno-facets-periodic-dft-study02047nas a2200217 4500008004100000022001400041245010000055210006900155260000800224300001500232490000600247520131900253653002201572653002601594653001401620653000801634653002101642100002001663700001801683856012801701 2022 eng d a2365-654900aLooking beyond adsorption energies to understand interactions at surface using machine learning0 aLooking beyond adsorption energies to understand interactions at cOCT ae2022024140 v73 a

Identifying factors that influence interactions at the surface is still an active area of research. In this work, the importance of analyzing bond length activations (BLact) along with adsorption energies (E-a) while interpreting Density Functional Theory (DFT) results is emphasized. Investigating adsorption of different small molecules, such as O-2, N-2, CO, and CO2, on commonly studied facets ((100), (110), and (111)) of seven fcc transition metal surfaces (M=Ag, Au, Cu, Ir, Rh, Pt, and Pd) demonstrates the missing linear correlation between E-a and BLact. Further, tree based Machine Learning (ML) models reinforce the missing linear correlation between the two parameters and also highlight the importance of analyzing both to develop a better understanding of adsorption at surfaces. The best performing Random Forest models have a mean absolute error (MAE) of 0.19 eV for E-a prediction, and even lower MAE of 0.012 angstrom for BLact prediction. While often d-band center is correlated with E-a, our observations show that infact the d-band center has a better correlation with BLact. These observations emphasizes the role of BLact in gaining a fuller picture for catalysis. The fact that the factors responsible for BLact is a lesser-explored subject adds to the novelty of the findings.

10aAdsorption energy10aBondlength activation10acatalysis10aDFT10amachine learning1 aAgarwal, Sheena1 aJoshi, Kavita uhttp://library.ncl.res.in/content/looking-beyond-adsorption-energies-understand-interactions-surface-using-machine-learning02229nas a2200193 4500008004100000022001400041245009700055210006900152260000900221300001600230490000600246520156000252100002101812700002501833700001801858700001801876700001701894856012401911 2022 eng d a2470-134300aPredicting the redox potentials of phenazine derivatives using DFT-assisted machine learning0 aPredicting the redox potentials of phenazine derivatives using D cAPR  a11742-117550 v73 a

This study investigates four machine-learning (ML) models to predict the redox potentials of phenazine derivatives in dimethoxyethane using density functional theory (DFT). A small data set of 151 phenazine derivatives having only one type of functional group per molecule (20 unique groups) was used for the training. Prediction accuracy was improved by a combined strategy of feature selection and hyperparameter optimization, using the external validation set. Models were evaluated on the external test set containing new functional groups and diverse molecular structures. High prediction accuracies of R2 > 0.74 were obtained on the external test set. Despite being trained on the molecules with a single type of functional group, models were able to predict the redox potentials of derivatives containing multiple and different types of functional groups with good accuracies (R2 > 0.7). This type of performance for predicting redox potential from such a small and simple data set of phenazine derivatives has never been reported before. Redox flow batteries (RFBs) are emerging as promising candidates for energy storage systems. However, new green and efficient materials are required for their widespread usage. We believe that the hybrid DFT-ML approach demonstrated in this report would help in accelerating the virtual screening of phenazine derivatives, thus saving computational and experimental costs. Using this approach, we have identified promising phenazine derivatives for green energy storage systems such as RFBs.

1 aGhule, Siddharth1 aDash, Soumya, Ranjan1 aBagchi, Sayan1 aJoshi, Kavita1 aVanka, Kumar uhttp://library.ncl.res.in/content/predicting-redox-potentials-phenazine-derivatives-using-dft-assisted-machine-learning02780nas a2200229 4500008004100000022001400041245012800055210006900183260000800252300001600260490000700276520196500283100003002248700002102278700002002299700002302319700001802342700001802360700001802378700002402396856013002420 2022 eng d a2050-748800aPseudo-boehmite AlOOH supported NGr composite-based air electrode for mechanically rechargeable Zn-air battery applications0 aPseudoboehmite AlOOH supported NGr compositebased air electrode  cMAY a10014-100250 v103 a

Both mechanically and electrically rechargeable zinc-air batteries (ZABs) have received much interest due to their high energy density and suitability for mobile and stationary applications. However, their commercialization has been impeded by the lack of robust, low-cost and environmentally benign catalyst materials that can be easily scaled up. In this context, the present work introduces a new type of transition metal-free catalytic material (AlOOH/NGr) by anchoring the pseudo-boehmite phase of aluminium oxyhydroxide (AlOOH) nanosheets over nitrogen-doped graphene (NGr) via a single-step and straightforward hydrothermal process. Furthermore, density functional theory (DFT) based computation demonstrates that the nucleation of AlOOH starts from the N-sites and points towards the strong surface interaction between AlOOH and NGr via doped nitrogen. AlOOH/NGr consisting of thin layered pseudo-boehmite sheets uniformly distributed over NGr has displayed an oxygen reduction reaction onset potential of 0.83 V and a half-wave potential of 0.72 V, along with good catalytic durability in alkaline medium. With this, AlOOH/NGr, when used as an air electrode for fabricating a primary Zn-air battery, the system has exhibited an open circuit voltage of similar to 1.27 V with a flat discharge profile at a current rate of 10 mA cm(-2). The fabricated system delivered a specific capacity of similar to 720 mA h g(-1) and a high power density of 204 mW cm(-2) and is comparable to the counterpart system based on the state-of-the-art Pt/C (20 wt% Pt) cathode. Additionally, the homemade battery was able to maintain its performance after 4 times of mechanical recharging of the battery, which lasted for more than 35 h at a discharge current density of 10 mA cm(-2). Thus, we have uncovered the potential of an earth-abundant metal-based catalytic system for fabricating and demonstrating a robust mechanically rechargeable zinc-air battery.

1 aKharabe, Geeta, Pandurang1 aManna, Narugopal1 aNadeema, Ayasha1 aSingh, Santosh, K.1 aMehta, Shweta1 aNair, Aathira1 aJoshi, Kavita1 aKurungot, Sreekumar uhttp://library.ncl.res.in/content/pseudo-boehmite-alooh-supported-ngr-composite-based-air-electrode-mechanically-rechargeable02008nas a2200241 4500008004100000022001400041245006900055210006900124260000800193300001100201490000800212520131900220653001201539653001201551653000801563653001601571653002501587653000801612100001801620700002001638700001801658856009001676 2022 eng d a0039-602800aRole of facet in the competitive pathway of ethylene epoxidation0 aRole of facet in the competitive pathway of ethylene epoxidation cFEB a1219540 v7163 aEthylene epoxide (EtO) is used as raw material for a broad range of products from pharmaceuticals and plastics to paints and adhesives. Although the reaction of ethylene interacting with preadsorbed oxygen on Ag surface is known for decades, the underlying mechanism of EtO formation is not completely understood. Successful investigation of oxametallacycle (OMC) intermediate common to selective as well as non-selective pathways has ensured at least 50% selectivity. The current study brings out the electronic signatures of distinct conformers of OMC stabilised on two different facets of Ag viz. (100) and (111). There are subtle differences between OMC conformers observed on these two facets with near-eclipsed on Ag(100) and near-staggered on Ag(111). A detailed analysis of Ag-O, C-O, C-C, and Ag-C interactions along with projected Density of States (pDOS) and projected Crystal Orbital Hamilton Population (pCOHP) imply towards ring closure on Ag(100) and hydrogen transfer on Ag(111). Finally, our understanding based on electronic and structural signatures are backed up by activation barriers computed through NEB calculations. Activation barrier for EtO is lower on (100) as compared to (111) facet. Thus, our study sheds light on how these differences between OMC affect the selectivity towards EtO.10aAg(100)10aAg(111)10aDFT10aepoxidation10aEthylene Oxide (EtO)10aOMC1 aNair, Aathira1 aKenge, Nivedita1 aJoshi, Kavita uhttp://library.ncl.res.in/content/role-facet-competitive-pathway-ethylene-epoxidation02916nas a2200229 4500008004100000022001400041245015400055210006900209260000900278300001600287490000700303520206700310100002702377700002102404700002302425700002102448700002302469700002002492700001802512700003002530856012602560 2023 eng d a2050-748800aBaby step in assembling and integrating the components of an artificial photosynthesis device with forced heterojunctions towards improved efficiency0 aBaby step in assembling and integrating the components of an art cJUL  a15168-151820 v113 a

How to achieve unassisted, economical, scalable, and sustainable artificial photosynthesis for liquid fuels/products with improved solar-to-fuel efficiency (STFE) to address a carbon-neutral economy remains a big question. To a large degree, the extent of charge separation at heterojunction interfaces and charge utilization determine the STFE. Towards this, BiVO3 is assembled from ionic-precursors into TiO2 pores, and integrated structurally and electronically with TiO2 on calcination as BiVO4 quantum dots (BVQDs). BVQDs in TiO2 (BVT) pores lead to an all-inorganic system with a sub-quadrillion number of heterojunctions in a 1 cm(2) device (contains similar to 25 mu g of BiVO4 (similar to 2.5 wt%) in the nanopores of similar to 975 mu g of TiO2 (similar to 97.5 wt%)) and facilitate artificial photosynthesis. We demonstrate 31-38% STFE with a photon to chemical conversion turn over frequency (ToF(P2C)) of 2.73 s(-1) with a 1 cm(2) wireless BiVO4-TiO2 artificial leaf (BVT-AL) device for HCHO and CH3OH. The sequential nature of CO2 reduction to HCHO and then to CH3OH is evident from the reaction results. (CO2)-C-13 isotopic labeling experiments confirm that the input CO2 is the source for product formation. A large increase in the photocurrent density and incident photon-to-current efficiency (IPCE) of BVT, over 100% for the BiVO4 photoanode in visible light, demonstrates and supports efficient visible light absorption, charge separation and migration to the redox sites. A device has been demonstrated to show sustainable activity in direct sunlight, and addresses scalability from 1 to 9 cm(2). Assuming no change (50% decrease) in the STFE, a 6.74 m(2) device is expected to convert 1 (0.5) kg h(-1) CO2 into C1-oxygenates in sunlight. DFT calculations carried out with anatase TiO2 (101) and BiVO4 (121) interfaces support many of the experimental findings, including electron flow from the latter to the former, and interaction of the oxygen of TiO2 with BiVO4 and vice versa at the interface towards forced heterojunctions.

1 aSalgaonkar, Kranti, N.1 aBajpai, Himanshu1 aMhamane, Nitin, B.1 aNalajala, Naresh1 aChauhan, Inderjeet1 aThakkar, Kavita1 aJoshi, Kavita1 aGopinath, Chinnakonda, S. uhttp://library.ncl.res.in/content/baby-step-assembling-and-integrating-components-artificial-photosynthesis-device-forced01604nas a2200217 4500008004100000022001400041245009500055210006900150260000800219300001100227490000800238520091100246653000801157653002601165653001301191653002101204653000801225100001801233700001801251856011701269 2023 eng d a0039-602800aElectronic fingerprints for diverse interactions of methanol with various Zn-based systems0 aElectronic fingerprints for diverse interactions of methanol wit cOCT a1223500 v7363 a

We have investigated various Zn-based catalysts for their interaction with methanol (MeOH). MeOH is one of the most critical molecules being studied extensively, and Zn-based catalysts are widely used in many industrially relevant reactions involving MeOH. We note that the same element (Zn and O, in the present study) exhibits different catalytic activity in different environments. The changing environment is captured in the underlying electronic structure of the catalysts. In the present work, we compared the electronic structure of Zn-based systems, i.e., ZnAl2O4 and ZnO along with oxygen preadsorbed Zn (O-Zn) and metallic Zn. We demonstrate the one-to-one correlation between the pDOS of the bare facet and the outcome of that facet's interaction (i.e. either adsorption or dissociation of MeOH) with MeOH. These findings would pave the way towards the in-silico design of catalysts.

10aDFT10aElectronic properties10aMethanol10aZn-based systems10aZnO1 aMehta, Shweta1 aJoshi, Kavita uhttp://library.ncl.res.in/content/electronic-fingerprints-diverse-interactions-methanol-various-zn-based-systems02812nas a2200253 4500008004100000022001400041245008900055210006900144260000800213300001600221490000700237520198700244653000802231653003302239653002302272653001602295653002602311653002802337100002002365700001802385700001802403700001902421856011802440 2023 eng d a0360-319900aHydrogen from catalytic non-thermal plasma-assisted steam methane reforming reaction0 aHydrogen from catalytic nonthermal plasmaassisted steam methane  cJUL a24328-243410 v483 a

Steam methane reforming reaction was carried out in a dielectric barrier plasma reactor. A systematic study is conducted to understand the influence of input power, flow rate, and water for the conversion, yield, and selectivity of the reaction over strategically designed catalysts. In particular, the production rate and selectivity of the products (H2, CO and C2 hydrocarbons) are monitored. CeO2 was used as packing material, mixed with oxides of manganese or copper and their combination. The optimum Cu/CeO2 catalyst illustrated the production rate of 248.7 mmolg-1h-1 and 11.25 mmolg-1h-1 for H2, and CO, respectively at specific energy input of 19.8 JL-1. DFT calculations exhibit apparent change in electronic structure of the CeO2 after inclusion of oxides of manganese and copper that enhance interaction with methane. Based on these findings, a plausible mechanism is elucidatedSteam methane reforming reaction was carried out in a dielectric barrier plasma reactor. A systematic study is conducted to understand the influence of input power, flow rate, and water for the conversion, yield, and selectivity of the reaction over strategically designed catalysts. In particular, the production rate and selectivity of the products (H2, CO and C2 hydrocarbons) are monitored. CeO2 was used as packing material, mixed with oxides of manganese or copper and their combination. The optimum Cu/CeO2 catalyst illustrated the production rate of 248.7 mmolg-1h-1 and 11.25 mmolg-1h-1 for H2, and CO, respectively at specific energy input of 19.8 JL-1. DFT calculations exhibit apparent change in electronic structure of the CeO2 after inclusion of oxides of manganese and copper that enhance interaction with methane. Based on these findings, a plausible mechanism is elucidated which can help to design catalyst for other applications in non-thermal plasma atmosphere. & COPY; 2023 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

10aDFT10aDielectric barrier discharge10aNon-thermal plasma10aselectivity10aSpecific energy input10aSteam methane reforming1 aBajpai, Abhinav1 aMehta, Shweta1 aJoshi, Kavita1 aKumar, Sushant uhttp://library.ncl.res.in/content/hydrogen-catalytic-non-thermal-plasma-assisted-steam-methane-reforming-reaction01767nas a2200205 4500008004100000245007600041210006900117260000900186300001100195490000600206520109400212653002101306653002701327653002501354100001701379700001901396700001801415700002101433856010701454 2023 eng d00aMeGen-generation of gallium metal clusters using reinforcement learning0 aMeGengeneration of gallium metal clusters using reinforcement le cJUN  a0250320 v43 a

The generation of low-energy 3D structures of metal clusters depends on the efficiency of the search algorithm and the accuracy of inter-atomic interaction description. In this work, we formulate the search algorithm as a reinforcement learning (RL) problem. Concisely, we propose a novel actor-critic architecture that generates low-lying isomers of metal clusters at a fraction of computational cost than conventional methods. Our RL-based search algorithm uses a previously developed DART model as a reward function to describe the inter-atomic interactions to validate predicted structures. Using the DART model as a reward function incentivizes the RL model to generate low-energy structures and helps generate valid structures. We demonstrate the advantages of our approach over conventional methods for scanning local minima on potential energy surface. Our approach not only generates isomer of gallium clusters at a minimal computational cost but also predicts isomer families that were not discovered through previous density-functional theory (DFT)-based approaches.

10agallium clusters10areinforcement learning10astructure generation1 aModee, Rohit1 aVerma, Ashwini1 aJoshi, Kavita1 aPriyakumar, Deva uhttp://library.ncl.res.in/content/megen-generation-gallium-metal-clusters-using-reinforcement-learning01972nas a2200241 4500008004100000022001400041245007800055210006900133260000800202300001200210490000800222520119700230653001801427653003701445653001901482653002601501100001701527700002001544700002001564700001801584700001901602856010901621 2023 eng d a0021-979700aPhotoinduced CO2 and N2 reductions on plasmonically enabled gallium oxide0 aPhotoinduced CO2 and N2 reductions on plasmonically enabled gall cJAN a654-6660 v6293 a

Ag-containing ZnO/ b-Ga2O3 semiconductor, which exhibit reduced bandgap, increased light absorption, and hydrophilicity, have been found to be useful for photocatalytic CO2 reduction and N2 fixation by water. The charge-separation is facilitated by the new interfaces and inherent vacancies. The Ag@GaZn demonstrated the highest photocurrent response, about 20-and 2.27-folds that of the Ga and GaZn sam-ples, respectively. CO, CH4, and H2 formed as products for photo-reduction of CO2. Ag@GaZn catalyst exhibited the highest AQY of 0.121 % at 400 nm (31.2 W/m2). Also, Ag@GaZn generated 740 lmolg-1 of NH4+ ions, which was about 18-folds higher than Ga sample. In situ DRIFTS for isotopic-labelled 13CO2 and 15N2 reaffirmed the photo-activity of as-synthesized catalysts. Density functional theory pro-vided insight into the relative affinity of different planes of heterostructures towards H2O, CO2 and N2 molecules. The structure-photoactivity rationale behind the intriguing Ag@GaZn sample offers a funda-mental insight into the role of plasmonic Ag and design principle of heterostructure with improved pho-toactivity and stability.(c) 2022 Elsevier Inc. All rights reserved.

10aCO2 reduction10aDRIFTS density functional theory10ahydrophilicity10aPhotocurrent response1 aOjha, Niwesh1 aThakkar, Kavita1 aBajpai, Abhinav1 aJoshi, Kavita1 aKumar, Sushant uhttp://library.ncl.res.in/content/photoinduced-co2-and-n2-reductions-plasmonically-enabled-gallium-oxide