02060nas a2200217   4500008004100000022001400041245019200055210006900247260007300316300001000389490000800399520116700407653002101574653002301595653002001618653002001638100001801658700001701676700001801693856013101711       2014                        eng d  a0040-603100aCharacterization, non-isothermal decomposition kinetics and photocatalytic water splitting of green chemically synthesized polyoxoanions of molybdenum containing phosphorus as hetero atom0 aCharacterization nonisothermal decomposition kinetics and photoc  aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcNOV  a29-360 v5963 a<p>In here, the green synthesis and thermal characterization of a novel polyoxoanions of molybdenum containing phosphorus as hetero atom are reported. The composition and morphology of the nanorods were established by fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), thermogravimetric analysis (TGA) and inductively coupled plasma atomic emission spectroscopic (ICP-AES) techniques. Thermal properties of the nanoparticles were investigated by non-isothermal analysis under nitrogen atmosphere. The values activation energy of each stage of thermal decomposition for all heating rates was calculated by Flynn-Wall-Ozawa (FWO) and Kissinger-Akahira-Sunnose (KAS) methods. Invariant kinetic parameter (IKP) method and master plot methodmere also used to evaluate the kinetic parameters and mechanism for the thermal decomposition of cetylpyridinium phosphomolybdate (CPM). Photocatalytic water oxidation mechanism using CPM catalyst in the presence of platinum (Pt) co-catalyst enhances the H-2 evolution and was found to be 1.514 mmol/g/h. (C) 2014 Elsevier B.V. All rights reserved.</p>10aKeggin structure10aMaster plot method10aPolyoxometalate10aWater oxidation1 aD'Cruz, Bessy1 aSamuel, Jadu1 aGeorge, Leena  uhttps://library.ncl.res.in/content/characterization-non-isothermal-decomposition-kinetics-and-photocatalytic-water-splitting-002171nas a2200169   4500008004100000022001400041245016900055210006900224260011000293300001600403490000600419520139500425100001801820700001701838700001801855856012801873       2014                        eng d  a2046-206900aGreen chemical incorporation of silicon into polyoxoanions of molybdenum: characterization, thermal kinetics study and their photocatalytic water splitting activity0 aGreen chemical incorporation of silicon into polyoxoanions of mo  aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcNOV  a63328-633370 v43 a<p>Cetylpyridinium silicomolybdate (CSM) nanorods were successfully synthesized by applying green chemistry principles using sodium molybdate and a structure directing cationic surfactant, cetyl pyridinium chloride (CPC) at room temperature. The composition and morphology of the nanorods were established by Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), thermogravimetric analysis (TG) and inductively coupled plasma atomic emission spectroscopic (ICP-AES) techniques. The thermal decomposition kinetics of CSM nanorods were investigated by a non-isothermal thermogravimetric analyzer at various heating rates. The thermal decomposition of CSM occurred in two stages. The activation energies of the first and second stages of thermal decomposition for all heating rates have been estimated using the iso-conventional methods of Flynn-Wall-Ozawa (FWO) and Kissinger-Akahira-Sunose (KAS) and the results are found to be in good agreement with each other. The invariant kinetic parameter (IKP) method and master plot method were also used to evaluate the kinetic parameters and mechanism for the thermal decomposition of CSM. The photocatalytic water oxidation mechanism using the CSM catalyst in the presence of platinum (Pt) co-catalyst enhances the H-2 evolution and was found to be 1.946 mmol g(-1) h(-1).</p>1 aD'Cruz, Bessy1 aSamuel, Jadu1 aGeorge, Leena  uhttps://library.ncl.res.in/content/green-chemical-incorporation-silicon-polyoxoanions-molybdenum-characterization-thermal-002194nas a2200181   4500008004100000022001400041245017800055210006900233260011000302300001400412490000700426520137300433100001801806700001701824700003401841700001801875856011901893       2014                        eng d  a1144-054600aGreen synthesis of novel polyoxoanions of tungsten containing phosphorus as a heteroatom: characterization, non-isothermal decomposition kinetics and photocatalytic activity0 aGreen synthesis of novel polyoxoanions of tungsten containing ph  aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcSEP  a5436-54440 v383 a<p>Synthesis of cetylpyridinium phosphotungstate (CPW) nanospheres was carried out by using sodium tungstate and a structure directing cationic surfactant, cetyl pyridinium chloride (CPC), at room temperature by applying green chemistry principles. The composition and morphology of the nanospheres were established by Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), atomic force microscopy (AFM), thermogravimetric analysis (TGA) and inductively coupled plasma atomic emission spectroscopic (ICP-AES) techniques. Thermal properties of the nanoparticles were investigated by nonisothermal analysis under a nitrogen atmosphere at four different heating rates 10, 15, 20 and 25 degrees C min(-1). The thermal decomposition of CPW occurred in two stages. The activation energy values at each stage of thermal decomposition for all heating rates were calculated by Flynn-Wall-Ozawa (FWO) and Kissinger-Akahira-Sunnose (KAS) methods. The invariant kinetic parameter (IKP) method and the master plot method were also used to evaluate the kinetic parameters and mechanism for the thermal decomposition of CPW. The photocatalytic water oxidation mechanism using a CPW catalyst in the presence of a platinum (Pt) co-catalyst enhances the H-2 evolution, which was found to be 2.0 mmol g(-1) h(-1).</p>1 aD'Cruz, Bessy1 aSamuel, Jadu1 aSreedhar, Mulloor, Kesavapill1 aGeorge, Leena  uhttps://library.ncl.res.in/content/green-synthesis-novel-polyoxoanions-tungsten-containing-phosphorus-heteroatom-002351nas a2200193   4500008004100000022001400041245011700055210006900172260011000241300001600351490000600367520155200373100002401925700002401949700001801973700001801991700002402009856012402033       2014                        eng d  a2040-336400aNitrogen-doped graphene interpenetrated 3D Ni-nanocages: efficient and stable water-to-dioxygen electrocatalysts0 aNitrogendoped graphene interpenetrated 3D Ninanocages efficient   aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcSEP  a13179-131870 v63 a<p>Herein, we report the synthesis of a nitrogen-doped graphene (NGr) interpenetrated 3D Ni-nanocage (Ni-NGr) electrocatalyst by a simple water-in-oil (w/o) emulsion technique for oxidation of water to dioxygen. Correlation of adsorption of NGr and subsequent interpenetration through the specific surface plane of nickel particles as well as the concomitant interaction of N and C with Ni in the nano-regime has been investigated. Apart from the benefits of the synergistic interactions between Ni, N, and C, the overall integrity of the structure and its intra-molecular connectivity within the framework help in achieving better oxygen evolution characteristics at a significantly reduced overpotential. The engineered Ni-NGr nanocage displays a substantially low overpotential of similar to 290 mV at a practical current density of 20 mA cm(-2) in 0.1 M KOH. In comparison, NGr and Ni-particles as separate entities give overpotentials of similar to 570 and similar to 370 mV under similar conditions. Moreover, the long term stability of Ni-NGr was investigated by anodic potential cycling for 500 cycles and an 8.5% increment in the overpotential at 20 mA cm(-2) was observed. Additionally, a chronoamperometric test was performed for 15 h at 20 mA cm(-2), which highlights the better sustainability of Ni-NGr under the actual operating conditions. Finally, the quantitative estimation of evolved oxygen was monitored by gas chromatography and was found to be 70 mmol h(-1) g(-1) of oxygen, which is constant in the second cycle as well.</p>1 aDhavale, Vishal, M.1 aGaikwad, Sachin, S.1 aGeorge, Leena1 aDevi, Nandini1 aKurungot, Sreekumar  uhttps://library.ncl.res.in/content/nitrogen-doped-graphene-interpenetrated-3d-ni-nanocages-efficient-and-stable-water-001731nas a2200181   4500008004100000022001400041245015100055210006900206260007100275300001400346490000800360520096800368100001801336700002601354700002101380700001801401856013001419       2015                        eng d  a1932-744700aSurface site modulations by conjugated organic molecules to enhance visible light activity of ZnO nanostructures in photocatalytic water splitting0 aSurface site modulations by conjugated organic molecules to enha  a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcFEB  a3060-30670 v1193 a<p>Surface modification of ZnO nanoparticles is identified as a method of modulating surface sites advantageously. ZnO nanoparticles of two different sizes are surface modified with a conjugated organic moiety to enable electron conduction and transfer. Enhanced H-2 evolution from water-methanol mixtures was observed in the composite systems compared to pristine ZnO under visible light irradiation without any cocatalyst. The system is also marginally active in water splitting in pure water without any sacrificial agents. Photophysical characterization indicates that even though reducing size into the nanoregime affects the band gap detrimentally, modifications by simple conjugated organic molecules assist in enhanced visible light activity. The experimental observations are corroborated with computational studies, which also point to a localization of valence band maximum of the interface on the organic moiety and conduction band minimum on ZnO.</p>1 aGeorge, Leena1 aSappati, Subrahmanyam1 aGhosh, Prasenjit1 aDevi, Nandini  uhttps://library.ncl.res.in/content/surface-site-modulations-conjugated-organic-molecules-enhance-visible-light-activity-zno-002113nas a2200229   4500008004100000022001400041245008000055210006900135260000900204300002300213490000600236520133300242100002201575700002601597700002101623700002701644700001801671700002801689700002401717700003001741856011201771       2016                        eng d  a1614-683200aLow band gap benzimidazole COF supported Ni3N as highly active OER catalyst0 aLow band gap benzimidazole COF supported Ni3N as highly active O  cDEC   aArticle No:16011890 v63 a<p>Covalent organic frameworks (COFs) have structures and morphologies closely resembling graphenes, whose modular construction permits atomiclevel manipulations. This, combined with their porous structure, makes them excellent catalyst supports. Here, the high electrocatalytic activity of a composite, formed by supporting Ni3N nanoparticles on a benzimidazole COF, for oxygen evolution reaction is shown. The composite oxidizes alkaline water with a near-record low overpotential of 230 mV @ 10 mA cm(-2) (eta(10)). This high activity is attributed to the ability of the COF to confine the Ni3N nanoparticles to size regimes otherwise difficult to obtain and to its low band gap character (1.49 eV) arising from the synergy between the conducting Ni3N nanoparticles and the pi-conjugated COF. The COF itself, as a metalfree self-standing framework, has an oxygen evolution reaction activity with 10 of 400 mV. The periodic structure of the COF makes it serve as a matrix to disperse the catalytically active Ni3N nanoparticles favoring their high accessibility and thereby good charge-transport within the composite. This is evident from the amount of O-2 evolved (230 mmol h(-1) g(-1)), which, to the best of our knowledge, is the highest reported. The work reveals the emergence of COF as supports for electrocatalysts.</p>1 aNandi, Shyamapada1 aSingh, Santosh, Kumar1 aMullangi, Dinesh1 aIllathvalappil, Rajith1 aGeorge, Leena1 aVinod, Chathakudath, P.1 aKurungot, Sreekumar1 aVaidhyanathan, Ramanathan  uhttps://library.ncl.res.in/content/low-band-gap-benzimidazole-cof-supported-ni3n-highly-active-oer-catalyst02041nas a2200253   4500008004100000022001400041245015600055210006900211260007300280300001000353490000800363520108600371653001901457653003501476653001801511653000801529653000801537100002901545700003201574700001801606700002201624700001801646856012301664       2016                        eng d  a1381-116900aPhotocatalytic H-2 evolution from water-methanol mixtures on InGaO3(ZnO)(m) with an anisotropic layered structure modified with CuO and NiO cocatalysts0 aPhotocatalytic H2 evolution from watermethanol mixtures on InGaO  aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcMAY  a82-880 v4153 a<p>InGaO3(ZnO)(m) series of oxides is found to be active for photocatalytic H-2 evolution from water-methanol mixtures. The structure of this series is highly anisotropic with InO6 octahedral layers sandwiching Ga/ZnOn polyhedra. The structural anisotropy in which the conducting layer is spatially separated from the charge generation sites may help in suppressing charge recombination and consequently enhance catalytic activity. The band gaps of the series obtained from absorption spectra are above 3.6 eV and hence they are not active under visible light irradiation. H-2 evolution is considerably enhanced under UV light on employing NiO as cocatalyst due to facile electron transfer from InGaO3(ZnO)(m). to NiO. However, when CuO is used as cocatalyst, visible light activity could be brought out. Due to the very low band gap of CuO, it can act as a sensitizer absorbing in visible light. The band positions become conducive for H-2 evolution due to band alignments consequent to electron accumulation in CuO conduction band. (C) 2016 Elsevier B.V. All rights reserved.</p>10aInGaO3(ZnO)(m)10aphotocatalytic water splitting10avisible light10aXPS10aXRD1 aNarendranath, Soumya, B.1 aThekkeparambil, Saranya, V.1 aGeorge, Leena1 aThundiyil, Shibin1 aDevi, Nandini  uhttps://library.ncl.res.in/content/photocatalytic-h-2-evolution-water-methanol-mixtures-ingao3znom-anisotropic-layered01808nas a2200205   4500008004100000022001400041245012700055210006900182260011000251300001600361490000700377520096600384100001801350700002801368700002701396700001801423700002401441700001801465856011901483       2016                        eng d  a1463-907600aUnderstanding the electron transfer process in ZnO-naphthol azobenzoic acid composites from photophysical characterisation0 aUnderstanding the electron transfer process in ZnOnaphthol azobe  aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcAUG  a22179-221870 v183 a<p>Semiconductor nanoparticles surface modified with organic molecules capable of visible light absorption and effectively transferring the electrons to the catalytic sites have the potential to be good photocatalysts. ZnO nanoparticles of size similar to 3 nm are grafted with two azonaphthols, one conjugated and the other non-conjugated. The photophysical properties of modified ZnO indicate an effective electron transfer from the conjugated azonaphthol to ZnO but not in the case of the non-conjugated molecule. It is also observed from lifetime studies that the conjugated molecule stabilises the defect sites on ZnO nanoparticles. It is possible that excited electrons from the conjugated molecule are transferred to specific defect sites in ZnO. This apparently does not occur in the non-conjugated molecule, bringing to focus the importance of the photophysical characteristics of organic modifiers in designing visible light active photocatalysts.</p>1 aGeorge, Leena1 aKunhikannan, Athira, K.1 aIllathvalappil, Rajith1 aOttoor, Divya1 aKurungot, Sreekumar1 aDevi, Nandini  uhttps://library.ncl.res.in/content/understanding-electron-transfer-process-zno-naphthol-azobenzoic-acid-composites02177nas a2200193   4500008004100000022001400041245017900055210006900234260000800303300001600311490000600327520141600333100002501749700001801774700002801792700001801820700002401838856012101862       2016                        eng d  a2046-206900aValorization of coffee bean waste: a coffee bean waste derived multifunctional catalyst for photocatalytic hydrogen production and electrocatalytic oxygen reduction reactions0 aValorization of coffee bean waste a coffee bean waste derived mu  cAUG  a82103-821110 v63 a<p>Here, we report the valorization of coffee bean waste (CBW) by producing nitrogen doped porous carbon (p-Cof) having both photocatalytic and electrocatalytic properties using a silica templating method. Morphological investigation of p-Cof reveals the presence of assemblies of highly porous flat carbon blocks. p-Cof exhibits a high surface area (1213 m(2) g(-1)) and a wide range of micro-and mesopores with good electrical conductivity. Along with this, the surface of p-Cof displays the presence of graphitic and pyridone-type nitrogen coordinations, which help p-Cof to perform as a multifunctional catalyst as revealed from its catalytic activities towards photocatalytic hydrogen production (PHP) and electrocatalytic oxygen reduction reactions. p-Cof produces 334 mu mol h(-1) g(-1) of hydrogen from water under visible light and 575 mmol h(-1) g(-1) of hydrogen under solar light irradiation with excellent stability. Along with this, p-Cof also displays improved oxygen reduction reaction (ORR) activity in alkaline medium. A better onset potential (0.91 V vs. RHE) and half-wave potential (0.75 V vs. RHE) are displayed by p-Cof compared to the catalyst derived from the simple annealing of CBW without employing the silica template. Along with the better electrochemical activity, p-Cof shows excellent ORR kinetics and electrochemical stability compared to the current state-of-the-art Pt/C.</p>1 aUnni, SreeKuttan, M.1 aGeorge, Leena1 aBhange, Siddheshwar, N.1 aDevi, Nandini1 aKurungot, Sreekumar  uhttps://library.ncl.res.in/content/valorization-coffee-bean-waste-coffee-bean-waste-derived-multifunctional-catalyst02076nas a2200169   4500008004100000245016700041210006900208260000800277300001000285490000800295520139400303100001801697700002601715700002101741700001801762856012601780       2018                        eng d00aSensitizing with short conjugated molecules: multimodal anchoring on ZnO nanoparticles for enhanced electron transfer characteristics, stability and H-2 evolution0 aSensitizing with short conjugated molecules multimodal anchoring  cJUL  a89-970 v3093 aSensitizing semiconductors with organic dyes is usually employed to improve efficiency of semiconductors towards visible light absorption and charge transport. However, till date most of the dyes are either noble metal based with complex and expensive synthesis procedure or have a very narrow absorption band. Further the photostability of the dyes is another important issue. In this work we have studied, using a combination of photophysical and computational methods, ZnO nanoparticles sensitized with transition metal free, cheap and easy to synthesize azoquinoline dye that has been designed to have multiple chelating sites, viz., carboxylic group and hydroxyl imine group as a photocatalyst for water splitting activity. We find that the presence of multiple chelating sites facilitates dual mode of anchoring on ZnO nanoparticles, which leads to enhanced photostability and H-2 generation of the composite. This is attributed to the incorporation of resonance features in the dye that increases electron transfer between ZnO and dye in contrast to the charge accumulation and photo degradation observed in non-conjugated and single site anchoring counterparts. Electron transfer from ZnO to dye under UV light and reverse in visible light could be identified experimentally. Such simple designing aspects can aid in identifying better catalysts for photocatalytic water splitting.1 aGeorge, Leena1 aSappati, Subrahmanyam1 aGhosh, Prasenjit1 aDevi, Nandini  uhttps://library.ncl.res.in/content/sensitizing-short-conjugated-molecules-multimodal-anchoring-zno-nanoparticles-enhanced01526nas a2200217   4500008004100000022001400041245010800055210006900163520072400232653002100956653001500977653003400992653002901026653001801055100002601073700001801099700002501117700001801142700002101160856012701181       2019                        eng d  a1867-388000aDescriptors to predict dye-sensitized semiconductor based photocatalyst for hydrogen evolution reaction0 aDescriptors to predict dyesensitized semiconductor based photoca3 a<p>Discovering efficient photocatalysts for hydrogen production from water splitting is highly desirable. Computational studies can help in rational designing of such catalysts through high throughput screening of materials. However, for that purpose one needs to identify descriptors that not only connects material properties with their functionality but are easy and inexpensive to compute. Using a combination of density functional theory based calculations and experiments we show two descriptors, namely, charge injection efficiency and electron hole separation, that can be used for in silico design of new and efficient dye-sensitized-semiconductor composites as catalysts for hydrogen evolution reaction.</p>
10acharge injection10adescriptor10adye-sensitized semiconductors10aelectron-hole separation10aH-2 evolution1 aSappati, Subrahmanyam1 aGeorge, Leena1 aSwamy, Vincent, Paul1 aDevi, Nandini1 aGhosh, Prasenjit  uhttps://library.ncl.res.in/content/descriptors-predict-dye-sensitized-semiconductor-based-photocatalyst-hydrogen-evolution01964nas a2200253   4500008004100000022001400041245011500055210006900170260000800239300001400247490000700261520109300268653001501361653001801376653001401394653001801408653002001426100003801446700001801484700002201502700002601524700003001550856013001580       2021                        eng d  a1867-388000aDurable metalloporphyrin 2D-polymer for photocatalytic hydrogen and oxygen evolution from river and sea waters0 aDurable metalloporphyrin 2Dpolymer for photocatalytic hydrogen a  cAPR  a1717-17210 v133 a<p>It is highly imaginary that the outcome of a combination of two complementary resources leads to answer an alarming global issue. One such possible example is the solar seawater splitting for `clean fuel' H-2 generation. Since the catalytic activity and stability of the photocatalysts are substantially challenged in seawater, the design of an efficient and stable photocatalyst is highly desirable. Herein, we demonstrate the solar seawater splitting by a two-dimensional polymer catalyst derived from metalloporphyrin bearing multi-hydroxyl groups. A bimetallic (Co and Ni) porphyrin 2D-polymer exhibits excellent long-term durability of 15 cycles of H-2 and O-2 generation in 200 days from pure water without a considerable decrease in efficiency. Detailed studies using river and seawaters also show the reliable performance of the catalyst over repeated cycles. Here the deactivation modes of catalytic activity have been nullified by the layered metalloporphyrin polymer structure through stable pi-pi stacking, signifying the molecular design of 2D-polymer photocatalyst.</p>
10a2D-polymer10aPhotocatalyst10aporphyrin10aSelf-assembly10awater splitting1 aRanjeesh, Kayaramkodath, Chandran1 aGeorge, Leena1 aMaibam, Ashakiran1 aKrishnamurty, Sailaja1 aBabu, Sukumaran, Santhosh  uhttps://library.ncl.res.in/content/durable-metalloporphyrin-2d-polymer-photocatalytic-hydrogen-and-oxygen-evolution-river-and