title: Solar-Driven H2 O2 Generation From H2 O and O2 Using Earth-Abundant Mixed-Metal Oxide@Carbon Nitride Photocatalysts.
abstract: Light-driven generation of H2 O2 only from water and molecular oxygen could be an ideal pathway for clean production of solar fuels. In this work, a mixed metal oxide/graphitic-C3 N4 (MMO@C3 N4 ) composite was synthesized as a dual-functional photocatalyst for both water oxidation and oxygen reduction to generate H2 O2 . The MMO was derived from a NiFe-layered double hydroxide (LDH) precursor for obtaining a high dispersion of metal oxides on the surface of the C3 N4 matrix. The C3 N4 is in the graphitic phase and the main crystalline phase in MMO is cubic NiO. The XPS analyses revealed the doping of Fe(3+) in the dominant NiO phase and the existence of surface defects in the C3 N4 matrix. The formation and decomposition kinetics of H2 O2 on the MMO@C3 N4 and the control samples, including bare MMO, C3 N4 matrix, Ni- or Fe-loaded C3 N4 and a simple mixture of MMO and C3 N4 , were investigated. The MMO@C3 N4 composite produced 63 μmol L(-1) of H2 O2 in 90 min in acidic solution (pH 3) and exhibited a significantly higher rate of production for H2 O2 relative to the control samples. The positive shift of the valence band in the composite and the enhanced water oxidation catalysis by incorporating the MMO improved the light-induced hole collection relative to the bare C3 N4 and resulted in the enhanced H2 O2 formation. The positively shifted conduction band in the composite also improved the selectivity of the two-electron reduction of molecular oxygen to H2 O2 .
authors.affiliation: State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, 15 Beisanhuan Dong Lu, Beijing, 100029, P.R. China.
authors.forename: Ruirui
authors.initials: R
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, 15 Beisanhuan Dong Lu, Beijing, 100029, P.R. China.
authors.forename: Kecheng
authors.initials: K
authors.lastname: Pan
authors.affiliation: State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, 15 Beisanhuan Dong Lu, Beijing, 100029, P.R. China.
authors.forename: Dandan
authors.initials: D
authors.lastname: Han
authors.affiliation: Joint Center for Artificial Photosynthesis, California Institute of Technology, Pasadena, California, 91125, USA.
authors.forename: Jingjing
authors.initials: J
authors.lastname: Jiang
authors.affiliation: Joint Center for Artificial Photosynthesis, California Institute of Technology, Pasadena, California, 91125, USA.
authors.forename: Chengxiang
authors.initials: C
authors.lastname: Xiang
authors.affiliation: Joint Center for Artificial Photosynthesis, California Institute of Technology, Pasadena, California, 91125, USA.|AFM Business Unit, Bruker Nano Surfaces, Santa Barbara, California, 93117, USA.
authors.forename: Zhuangqun
authors.initials: Z
authors.lastname: Huang
authors.affiliation: State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, 15 Beisanhuan Dong Lu, Beijing, 100029, P.R. China.|Joint Center for Artificial Photosynthesis, California Institute of Technology, Pasadena, California, 91125, USA.
authors.forename: Lu
authors.initials: L
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, 15 Beisanhuan Dong Lu, Beijing, 100029, P.R. China. xiangxu@mail.buct.edu.cn.
authors.forename: Xu
authors.initials: X
authors.lastname: Xiang
mesh_terms: D002384:Catalysis; D005290:Ferric Compounds / Q000737:chemistry*; D006108:Graphite / Q000737:chemistry; D006861:Hydrogen Peroxide / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D009532:Nickel / Q000737:chemistry*; D009570:Nitriles / Q000737:chemistry*; D010084:Oxidation-Reduction; D010100:Oxygen / Q000737:chemistry*; D055668:Photochemical Processes; D013472:Sunlight; D014867:Water / Q000737:chemistry*
chemical_list: D005290:Ferric Compounds; D009570:Nitriles; D014867:Water; C000499:ferric oxide; C011206:cyanogen; D006108:Graphite; D009532:Nickel; D006861:Hydrogen Peroxide; C028007:nickel monoxide; D010100:Oxygen
keywords: hydrogen peroxide; mixed metal oxide; oxygen reduction; photocatalysis; sustainable chemistry