03098nas a2200277 4500008004100000022001400041245012600055210006900181260000900250300001200259490000600271520215500277653001902432653001902451653001902470653001402489653001202503100002302515700002102538700002902559700002902588700002402617700001902641700003002660856013002690 2023 eng d a2574-096200aFacile one-pot synthesis of Cu x O/TiO2 photocatalysts by regulating Cu oxidation state for efficient solar H2 production0 aFacile onepot synthesis of Cu x OTiO2 photocatalysts by regulati cDEC  a104-1160 v73 a

Development of highly efficient CuxO/TiO2 photocatalysts by regulating the oxidation state of Cu exclusively in either single or mixed oxidation state(s) is desirable but difficult to achieve without employing any external reagents. The present work describes a one-pot synthesis strategy to obtain CuxO/TiO2 photocatalysts with Cu in +1 and/or +2 by using a suitable combination of ethylene diamine tetra acetic acid (EDTA) and ethylene diamine, carefully varying the Cu content, and heat treatment process. CuxO/TiO2 nanocomposite catalysts were characterized thoroughly by physicochemical methods. Textural analysis indicates a high dispersion of CuxO on porous TiO2 with p-n heterojunctions between them in CuxO/TiO2 catalysts. UV-visible spectral analysis suggests the presence of CuxO on TiO2 with significantly extended absorption from the UV to the visible region. X-ray photoelectron spectroscopy (XPS) analysis indicates a strong synergetic interaction between TiO2 and CuxO due to the comparable CB potential and p-n heterojunction at the interface among them. Photoelectrochemical studies demonstrate excellent charge-carrier separation efficiency, low charge-transfer resistance, and high double-layer capacitance with Cu2O/TiO2 photocatalysts. Photocatalytic efficacy of a CuxO/TiO2 nanocomposite in thin-film form has been demonstrated for solar hydrogen generation in sunlight. The incorporation of Cu+ in TiO2 largely improves the H-2 production, and all of the CuxO/TiO2 nanocomposites in thin-film form exhibited higher efficiency compared to their particulate/suspension counterpart. Among the composite catalysts, TiCu-1 in thin-film form, with Cu exclusively in +1 oxidation state, exhibited a high hydrogen production rate of 7.06 mmol/hg, which is 6 times higher than its suspension counterpart; also catalysts containing mixed Cu-oxidation states exhibited about 60-70% activity as that of TiCu-1. The superior performance of Cu2O/TiO2 nanocomposites in thin-film form was due to their enhanced light harvesting ability, high mass transfer rate, and easy accessibility of the reactant species to the active sites.

10aheterojunction10aPhotocatalysis10aSolar hydrogen10athin film10atitania1 aRajendran, Sivaraj1 aMani, Sunesh, S.1 aNivedhitha, Thazhath, R.1 aAsoka, Anantha, Krishnan1 aArun, Pushkaran, S.1 aMathew, Thomas1 aGopinath, Chinnakonda, S. uhttps://library.ncl.res.in/content/facile-one-pot-synthesis-cu-x-otio2-photocatalysts-regulating-cu-oxidation-state-efficient02809nas a2200265 4500008004100000022001400041245016300055210006900218260000800287300001600295490000700311520183300318653002202151653002702173653002202200653002402222653002002246100002902266700002102295700002902316700002002345700002302365700003002388856012502418 2024 eng d a2168-048500aAqueous glycerol to glyceric acid and green hydrogen by visible-light-driven photocatalysis with Ni/Co(PO4)2-TiO2: parallel utilization of holes and electrons0 aAqueous glycerol to glyceric acid and green hydrogen by visiblel cSEP a14841-148530 v123 a

Replacing the kinetically sluggish oxygen evolution reaction (OER) with the oxidation of an abundantly available organic molecule to value-added product(s) (VAPs) at low voltage along with the hydrogen evolution reaction (HER) is a big challenge in water splitting, either by electrolysis or sunlight-driven photocatalysis. Glycerol oxidation to a VAP is kinetically fast, compared to an OER, and offers hope to enhance sunlight-driven water splitting to hydrogen by the concurrent utilization of holes and electrons. Mixed bimetal phosphates of Co and Ni (CoxNiy(PO4)(2) (CoNiP)) with different Co:Ni ratios (10:0, 7:3, 5:5, 3:7, and 0:10) were integrated with TiO2 to generate final photocatalyst composites (x wt % CoNiP with TiO2) and employed for concurrent photocatalytic HER and glycerol oxidation. Irrespective of the weight ratios of CoNiP and TiO2, any TiO2-CoNiP composite showed better photocatalytic activity for the HER and glycerol oxidation compared to virgin TiO2. The highest HER as well as selectively generated glyceric acid yield was observed to be 54 and 67 mmol/g, respectively, after 25 h of reaction under 1 sun conditions with TiO2-CoNiP-5:5. An increase in catalytic activity can be attributed to the formation of p-n heterojunctions of the constituent component along with uniform distribution of CoNiP to effectively utilize the charge carriers for redox reactions. Highly selective oxidation of glycerol to glyceric acid (85%), along with other minor products, is also demonstrated, which offers further scope to use solar light to generate VAPs in a sustainable manner. A simple comparison of H-2 yield and all oxidized products together indicates the better utilization of holes for the latter, and hence, there is scope to increase HER and possibly the whole photocatalytic activity.

10abiomass component10aearth-abundantmaterial10aenergy conversion10aorganicvalorisation10awater splitting1 aNivedhitha, Thazhath, R.1 aBajpai, Himanshu1 aOommen, Jiffin, Varghese1 aAbraham, Athira1 aChauhan, Inderjeet1 aGopinath, Chinnakonda, S. uhttps://library.ncl.res.in/content/aqueous-glycerol-glyceric-acid-and-green-hydrogen-visible-light-driven-photocatalysis02551nas a2200253 4500008004100000022001400041245017900055210006900234260000800303300001100311490000800322520161300330653001801943653001301961653001901974653002201993653002802015100002102043700002902064700001502093700002802108700003002136856013102166 2024 eng d a0021-951700aOxidative and selective C-C cleavage of glycerol to glycolaldehyde with atom-like Cu on Cu-TiO2: photocatalytic water reduction with concurrent glycerol oxidation in sunlight0 aOxidative and selective CC cleavage of glycerol to glycolaldehyd cSEP a1156440 v4373 a

Concurrent consumption of electrons and holes for the conversion of a biomass component to value added products represents a highly efficient and sustainable approach towards utilizing renewable energy, but difficult to achieve. The integration of hydrogen production with glycerol oxidation presents a novel and sustainable approach towards achieving a circular economy. In the current study, integration of atom-like Cu-clusters onto TiO2 substrate has been achieved using a facile photo-deposition technique (TC-PDO). Also, novel synthetic approaches have been employed to augment the surface coverage of Cu on TiO2 with atom-like clusters of Cu, either by borohydride treatment on TiO2 followed by Cu-deposition (TC-200) or oxygen-vacancy creation by UV illumination followed by Cu-deposition (TC-PDO). Increased dispersion and enhanced electronic integration of Cu with TiO2 lead to a corresponding increase in the efficiency of photocatalytic hydrogen evolution (13.8 mmol/h.g for TC-PDO at pH 9). Several atom-like Cu integrated with each TiO2 particle acts as photocatalytic reactor, and the same enhances electron-hole separation as well as activity. Sustainable aspect was also studied for TC-PDO up to 25 h at pH 9. Concurrently, glycerol oxidation displays the highest selectivity to C2 product (glycolaldehyde with 70 %) with a C-C cleavage. The investigation of this process holds significant potential for the extensive and simultaneous exploitation of electrons and holes in order to achieve water splitting and glycerol oxidation towards selective value-added products formation.

10aC -C Cleavage10aGlycerol10ananotechnology10aPhoto -deposition10asolar energy conversion1 aBajpai, Himanshu1 aNivedhitha, Thazhath, R.1 aDais, Elsa1 aKanungo, Subhashree, S.1 aGopinath, Chinnakonda, S. uhttps://library.ncl.res.in/content/oxidative-and-selective-c-c-cleavage-glycerol-glycolaldehyde-atom-cu-cu-tio2-photocatalytic02326nas a2200277 4500008004100000022001400041245012700055210006900182260000800251490000700259520134800266653002301614653002601637653002401663653001901687653001201706100002001718700002701738700002901765700002401794700002301818700002801841700003001869700001801899856013101917 2025 eng d a1861-472800aSynthesis of Pd-integrated carbon Dot@TiO2 thin film for photocatalytic glycerol reforming reaction for producing hydrogen0 aSynthesis of Pdintegrated carbon DotTiO2 thin film for photocata cNOV0 v203 a

A series of thin-film photocatalysts comprising TiO2 modified with carbon dots (CDs) dispersed either with palladium (Pd-CD/TiO2) or nickel (Ni-CD/TiO2) were synthesized via solid-state and wet-impregnation methods. Morphological characterization (HR-TEM, SEM-EDS) confirmed the anatase phase of TiO2 and the atomic dispersion of metal-integrated CDs on its surface. UV-vis DRS and XPS analyses revealed a marginal red shift in band-gap and the presence of sp2-hybridized graphitic carbon, and metal-carbon interactions, indicating enhanced light absorption and charge separation through Schottky junctions. Under direct sunlight illumination, Pd-CD/TiO2 thin film exhibited superior hydrogen yield (1167 mu mol g-1 h-1) and maintained stability over 25 h, outperforming Ni-CD/TiO2 (494 mu mol g-1 h-1) and bare TiO2 (166 mu mol g-1 h-1) photocatalyst thin films. Concurrent glycerol oxidation at neutral pH (pH similar to 7) yields glycolaldehyde (41% selectivity), formic acid, and dihydroxyacetone as value-added products. Enhanced photocurrent density and lower impedance of Pd-CD/TiO2 corroborate improved charge carrier separation and dynamics. The results demonstrate that Pd-CD synergistically improves the photocatalytic performance of the Pd-CD/TiO2 for sustainable hydrogen generation and selective biomass valorization.

10aGlycerol oxidation10aGraphitic carbon dots10ahydrogen production10aPhotocatalysis10atitania1 aAbraham, Athira1 aSalgaonkar, Kranti, N.1 aNivedhitha, Thazhath, R.1 aEkal, Vishal, Ashok1 aKondhekar, Deepali1 aChakraborty, Shubhankar1 aGopinath, Chinnakonda, S.1 aSaha, Avishek uhttps://library.ncl.res.in/content/synthesis-pd-integrated-carbon-dottio2-thin-film-photocatalytic-glycerol-reforming-reaction