Rhodium-doped calcium niobate nanosheets were synthesized by exfoliating layered KCa 2Nb 3-xRh xO 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.
All Science Journal Classification (ASJC) codes
- Colloid and Surface Chemistry