title: Solar photochemical and thermochemical splitting of water.
abstract: Artificial photosynthesis to carry out both the oxidation and the reduction of water has emerged to be an exciting area of research. It has been possible to photochemically generate oxygen by using a scheme similar to the Z-scheme, by using suitable catalysts in place of water-oxidation catalyst in the Z-scheme in natural photosynthesis. The best oxidation catalysts are found to be Co and Mn oxides with the e(1) g configuration. The more important aspects investigated pertain to the visible-light-induced generation of hydrogen by using semiconductor heterostructures of the type ZnO/Pt/Cd1-xZnxS and dye-sensitized semiconductors. In the case of heterostructures, good yields of H2 have been obtained. Modifications of the heterostructures, wherein Pt is replaced by NiO, and the oxide is substituted with different anions are discussed. MoS2 and MoSe2 in the 1T form yield high quantities of H2 when sensitized by Eosin Y. Two-step thermochemical splitting of H2O using metal oxide redox pairs provides a strategy to produce H2 and CO. Performance of the Ln0.5A0.5MnO3 (Ln = rare earth ion, A = Ca, Sr) family of perovskites is found to be promising in this context. The best results to date are found with Y0.5Sr0.5MnO3.
authors.affiliation: New Chemistry Unit, Chemistry and Physics of Materials Unit, CSIR- Centre of Excellence in Chemistry, International Centre for Materials Science and Sheikh Saqr Laboratory, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur PO, Bangalore 560064, India cnrrao@jncasr.ac.in.
authors.forename: C N R
authors.initials: CN
authors.lastname: Rao
authors.affiliation: New Chemistry Unit, Chemistry and Physics of Materials Unit, CSIR- Centre of Excellence in Chemistry, International Centre for Materials Science and Sheikh Saqr Laboratory, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur PO, Bangalore 560064, India.
authors.forename: S R
authors.initials: SR
authors.lastname: Lingampalli
authors.affiliation: New Chemistry Unit, Chemistry and Physics of Materials Unit, CSIR- Centre of Excellence in Chemistry, International Centre for Materials Science and Sheikh Saqr Laboratory, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur PO, Bangalore 560064, India.
authors.forename: Sunita
authors.initials: S
authors.lastname: Dey
authors.affiliation: New Chemistry Unit, Chemistry and Physics of Materials Unit, CSIR- Centre of Excellence in Chemistry, International Centre for Materials Science and Sheikh Saqr Laboratory, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur PO, Bangalore 560064, India.
authors.forename: Anand
authors.initials: A
authors.lastname: Roy
mesh_terms: D002384:Catalysis; D003035:Cobalt / Q000737:chemistry* / Q000528:radiation effects; D006358:Hot Temperature; D006859:Hydrogen / Q000737:chemistry / Q000302:isolation & purification* / Q000528:radiation effects; D008027:Light; D017895:Manganese Compounds / Q000737:chemistry* / Q000528:radiation effects; D010087:Oxides / Q000737:chemistry* / Q000528:radiation effects; D010100:Oxygen / Q000737:chemistry / Q000302:isolation & purification* / Q000528:radiation effects; D055668:Photochemical Processes / Q000528:radiation effects*; D010777:Photochemistry / Q000379:methods; D012666:Semiconductors; D012993:Solar Energy; D014867:Water / Q000737:chemistry*
chemical_list: D017895:Manganese Compounds; D010087:Oxides; D014867:Water; D003035:Cobalt; C027424:manganese oxide; D006859:Hydrogen; D010100:Oxygen; C060728:cobalt oxide
keywords: hydrogen production; oxidation of water; photocatalytic water splitting; thermochemical CO2 splitting; thermochemical water splitting