03405nas a2200229 4500008004100000022001400041245021300055210006900268260000800337300001600345490000800361520247400369100002702843700002202870700003402892700001802926700001902944700002602963700003002989700002703019856012903046 2020 eng d a1932-744700aUnsymmetrical squaraine dyes for dye-sensitized solar cells: position of the anchoring group controls the orientation and self-assembly of sensitizers on the TiO2 surface and modulates its flat band potential0 aUnsymmetrical squaraine dyes for dyesensitized solar cells posit cAUG a18436-184510 v1243 a

The position of the anchoring group is systematically changed with a series of alkyl group wrapped donor-acceptor-donor (D-A-D) based squaraine dyes, 4-SQ to 7-SQ, for the use in dye-sensitized solar cells (DSSCs). By this approach, the orientation as well as the self-assembly of the sensitizers can be controlled on the semiconducting TiO2 surface. All of the dyes functionalized with hydrophobic alkyl groups at sp(3)-C and N atoms of the indoline units that is far away from the TiO2 surface to control the self-assembly of dyes and passivate the surface. Controlling both the orientation as well as the self-assembly of the sensitizers synergistically enhances the V-oc of the DSSC device by imparting the dipole moment on the TiO2 surface and minimizing the interfacial charge recombination process of electrons from TiO2 to the oxidized electrolyte, respectively. Further, the presence of a meta-carboxyl group with respect to the N atom of the indoline donor unit for the dyes 4-SQ and 6-SQ makes them nonconductive for the charge injection process, which sheds light on the importance of through-space electron transfer for the device performance. Emission from the relaxed twisted state was found to be a deactivation pathway for 4-SQ on TiO2 and ZrO2, which revealed the importance of structural factors that promote spatial interaction between the sensitizer and metal oxide surface. Computational studies showed the systematic changes in the dipole moment for the sensitizers 4-SQ, 5-SQ, and 6-SQ upon anchoring to the TiO2 surface. The DSSC device performance varied with the position of anchoring groups in the sensitizers. The DSSC device performance of 5-SQ indicates a J(sc) value of 11.35 mA cm(-2), V-oc of 0.698 V, and ff of 77% corresponding to a power conversion efficiency of 6.08% in the presence of 3 equiv of coadsorbent CDCA, which is nearly 1.5 times higher than 6-SQ (V-oc 0.7 V, J(sc) 7.76 mA cm(-2), ff 76%, and eta 4.14%) and 2.6 times higher than 4-SQ (V-oc 0.658 V, J(sc) 4.42 mA cm(-2), ff 78%, and eta 2.28%). IPCE studies revealed the importance of orientation for the charge injection and self-assembly of dyes, as devices with 5-SQ and 6-SQ as a sensitizer showed 94 and 77% response at 578 nm, respectively, which correspond to the aggregated structure of the dye. Mott-Schottky and IPCE experiments showed that the orientation of sensitizers could modulate the V-oc due to the shift in the flat band potential of TiO2.

1 aSingh, Ambarish, Kumar1 aMaibam, Ashakiran1 aJavaregowda, Bharathkumar, H.1 aBisht, Rajesh1 aKudlu, Ashwath1 aKrishnamurty, Sailaja1 aKrishnamoorthy, Kothandam1 aNithyanandhan, Jayaraj uhttps://library.ncl.res.in/content/unsymmetrical-squaraine-dyes-dye-sensitized-solar-cells-position-anchoring-group-controls02578nas a2200217 4500008004100000022001400041245015200055210006900207260000800276490000700284520173800291653003002029653003702059653003002096653001702126100002502143700002202168700002602190700001802216856012602234 2024 eng d a0934-086600aUltra-small Au nanoclusters with tailored photoluminescence properties using modified thiol ligands: a computational and experimental demonstration0 aUltrasmall Au nanoclusters with tailored photoluminescence prope cOCT0 v413 a

Au nanoclusters with tailored photoluminescence can be obtained through controlled nanoparticle ligand interface chemistry. The present work reports molecular gold nanoclusters with tuneable photoluminescence emission from 600 to 700 nm using N,N `,N `'-trialkyl (11-mercaptoundecyl)ammonium chloride ligands as capping-agents. The tunability within red spectral region is regulated through specific interface chemistry between gold nanoclusters of molecular range and functional groups of the quaternary ammonium head over N,N `,N `'-trialkyl(11-mercaptoundecyl)ammonium chloride. Combined understanding obtained from the spectroscopy, microscopy, and density functional theory studies demonstrate that the functional group specific electronic interactions at the interfaces steer the emission characteristics of ``molecular'' Au nanoparticles. The study clearly identifies that bulkier functional groups, i.e., triethyl, tripropyl, tributyl, and dimethyl benzene over N+ (of thiol ligand) through their steric effects minimize the particle size giving rise to tunable photoluminescence emission in red spectral region. However, the red shift seen in the emission Au nanoclusters with N-(11-mercaptoundecyl)-N,N `-dimethylbenzenammonium chloride ligand in contradiction to particle size effect is computationally proved to be due to the delocalization of electron density from benzene aromatic ring to N+ of ammonium head leading to a reduction in the HOMO-LUMO energy gap. Fluorescence properties of water dispersible Au nanoclusters are tuned by varying the ammonium head group. Density Functional Theory studies correlate the distinction in emission when head group is phenyl to charge transfer characteristics. image

10aDensity functional theory10aphotoluminescent Au nanoclusters10asurface plasmon resonance10athiol ligand1 aChahande, Anurag, M.1 aMaibam, Ashakiran1 aKrishnamurty, Sailaja1 aDevi, Nandini uhttps://library.ncl.res.in/content/ultra-small-au-nanoclusters-tailored-photoluminescence-properties-using-modified-thiol02243nas a2200313 4500008004100000022001400041245015900055210006900214260000800283300001100291490000800302520113800310653002401448653001901472653002301491653002001514653002001534653003501554653002301589100002801612700002601640700002201666700002901688700001801717700002301735700002201758700001801780856013101798 2025 eng d a1385-894700aUnravelling the Cu-Co nanoparticle synergy over Ceria-Zirconia support toward efficient reverse water gas shift (RWGS) conversion under H2 lean conditions0 aUnravelling the CuCo nanoparticle synergy over CeriaZirconia sup cMAR a1607050 v5083 a

CO2 emissions leading to global warming and environmental and socio-economic issues have propelled the research community to develop technologies capable of capturing and converting CO2 into valuable products. Controlling the selectivity toward platform molecules like CO, methanol, or methane is a fundamental challenge in CO2 hydrogenation. Supported cobalt nanoparticles are known for hydrocarbon production through FischerTropsch (FT) reaction, and Cu-based catalysts are known for reverse water gas shift (RWGS) reaction. Here, we show that d-band centre can be carefully modulated by making bimetallic combinations of Cu and Co for a highly active RWGS catalyst. An oxygen vacancy-rich nanostructured ceria-zirconia (CZ) support with Cu nanoparticles (2 wt%) modified with as low as 0.05 wt% Co shows excellent conversion for CO2 hydrogenation and selectivity for CO below 500 degrees C. The optimized catalyst shows CO2 conversion even under hydrogen lean conditions (H2/ CO2 ratio 0.5:1), with a breakthrough rate of 206023 mmol/gmetal/h for CO at 600 degrees C, having H2 utilization of 80% for the RWGS process.

10aBimetallic catalyst10aCeria-zirconia10aCO 2 hydrogenation10aCobalt catalyst10aCopper catalyst10aReverse water gas shift (RWGS)10asynergistic effect1 aJagtap, Anuradha, Vijay1 aBamnia, Mahesh, Kumar1 aMaibam, Ashakiran1 aBajpai, Jyotsna, Paliwal1 aGupta, Sharad1 aThomas, Sharon, K.1 aDabke, Niteen, B.1 aVinod, C., P. uhttps://library.ncl.res.in/content/unravelling-cu-co-nanoparticle-synergy-over-ceria-zirconia-support-toward-efficient-reverse