title: Synthesis and photocatalytic activity of rhodium-doped calcium niobate nanosheets for hydrogen production from a water/methanol system without cocatalyst loading.
abstract: Rhodium-doped calcium niobate nanosheets were synthesized by exfoliating layered KCa(2)Nb(3-x)Rh(x)O(10-δ) and exhibited high photocatalytic activity for H(2) production from a water/methanol system without cocatalyst loading. The maximum H(2) production rate of the nanosheets was 165 times larger than that of the parent Rh-doped layered oxide. The quantum efficiency at 300 nm was 65%. In this system, the methanol was oxidized to formaldehyde (main product), formic acid, and carbon dioxide by holes, whereas electrons cause the reduction of water to H(2). The conductivity of the parent layered oxide was decreased by doping, which indicates the octahedral RhO(6) unit in the lattice of the nanosheet functions as an electron trap site. The RhO(6) units in the nanosheet probably also act as reaction sites for H(2) evolution.
authors: Department of Applied Chemistry, Faculty of Engineering, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan.
authors: Yohei
authors: Y
authors: Okamoto
authors: Shintaro
authors: S
authors: Ida
authors: Junji
authors: J
authors: Hyodo
authors: Hidehisa
authors: H
authors: Hagiwara
authors: Tatsumi
authors: T
authors: Ishihara
mesh_terms: D002384:Catalysis; D006859:Hydrogen / Q000737:chemistry*; D000432:Methanol / Q000737:chemistry; D057145:Nanoshells / Q000737:chemistry*; D009556:Niobium / Q000737:chemistry*; D009942:Organometallic Compounds / Q000138:chemical synthesis* / Q000737:chemistry*; D010316:Particle Size; D055668:Photochemical Processes; D012238:Rhodium / Q000737:chemistry*; D013499:Surface Properties; D014867:Water / Q000737:chemistry
chemical_list: D009942:Organometallic Compounds; D009556:Niobium; D014867:Water; D006859:Hydrogen; D012238:Rhodium; D000432:Methanol