01731nas 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

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.

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-001904nas a2200205 4500008004100000022001400041245015400055210006900209260000800278300001400286490000700300520113000307100001701437700002601454700002301480700002401503700002101527700002101548856012901569 2016 eng d a1477-922600aCoordination polymers of Fe(III) and Al(III) ions with TCA ligand: distinctive fluorescence, CO2 uptake, redox-activity and oxygen evolution reaction0 aCoordination polymers of FeIII and AlIII ions with TCA ligand di cFEB a6901-69080 v453 a

Fe and Al belong to different groups in the periodic table, one from the p-block and the other from the d-block. In spite of their different groups, they have the similarity of exhibiting a stable 3+ oxidation state. Here we have prepared Fe(III) and Al(III) based coordination polymers in the form of metal-organic gels with the 4,4', 4 `'-tricarboxyltriphenylamine (TCA) ligand, namely Fe-TCA and Al-TCA, and evaluated some important physicochemical properties. Specifically, the electrical conductivity, redox-activity, porosity, and electrocatalytic activity (oxygen evolution reaction) of the Fe-TCA system were noted to be remarkably higher than those of the Al-TCA system. As for the photophysical properties, almost complete quenching of the fluorescence originating from TCA was observed in case of the Fe-TCA system, whereas for the Al-TCA system a significant retention of fluorescence with red-shifted emission was observed. Quantum mechanical calculations based on density functional theory (DFT) were performed to unravel the origin of such discriminative behaviour of these coordination polymer systems.

1 aDhara, Barun1 aSappati, Subrahmanyam1 aSingh, Santosh, K.1 aKurungot, Sreekumar1 aGhosh, Prasenjit1 aBallav, Nirmalya uhttps://library.ncl.res.in/content/coordination-polymers-feiii-and-aliii-ions-tca-ligand-distinctive-fluorescence-co2-uptake02076nas 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

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.

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-evolution01403nas a2200325 4500008004100000022001400041245011300055210006900168260000900237300001100246490000800257520032000265653003000585653003500615653002600650653000900676653002600685653002500711100002000736700002100756700002700777700001900804700002000823700002000843700002000863700002600883700002000909700002200929856012600951 2025 eng d a0304-885300aElectronic, magnetic, and mechanical properties of co-doped GaSb: A promising diluted magnetic semiconductor0 aElectronic magnetic and mechanical properties of codoped GaSb A  cNOV  a1734990 v6323 a

{Understanding the interplay between magnetism and the electronic structure is crucial for the development of novel spintronic materials. This study employs density functional theory (DFT) calculations to investigate these properties in cubic Gallium Antimonide (GaSb) doped with Cobalt (Co) (Ga1-xCoxSb

10aDensity functional theory10aDilute magnetic semiconductors10aElectronic properties10aGaSb10amechanical properties10aSpintronic materials1 aSamant, Ramnath1 aSaraf, Deepashri1 aAdhikari, Rajendra, P.1 aShilkar, Omkar1 aRaikar, Sakshit1 aSilveira, Allan1 aSawant, Manthan1 aSappati, Subrahmanyam1 aJoshi, Niharika1 aDesai, Ashish, M. uhttps://library.ncl.res.in/content/electronic-magnetic-and-mechanical-properties-co-doped-gasb-promising-diluted-magnetic