| 초록 |
Bismuth vanadate (BiVO4) is a well-known photocatalyst for solar-driven water splitting because of its relatively narrow band gap (2.4 eV) and proper band edges for oxygen evolution reaction (OER). However, the efficiency of BiVO4 photoanodes has been reported less than those expected theoretically due to its poor electrical conductivity and slow kinetics of the OER by alone. To enhance its OEC activity, various strategies have been proposed and they include second-elementary (Mo or W, etc) doping, the formation of heterojunction using metal oxide buffer layers (SnO2 or WO3, etc), and decoration of co-catalysts (Co-Pi, FeOOH, NiOx, etc. In this talk, we discuss the effects of varying the thickness of a SnO2 buffer layer and tuning the chemistry of a BiVO4, such as Bi/V stoichiometry and extrinsic doping with Mo, on photoelectrochemical (PEC) performance of the SnO2/BiVO4 photoanodes. We found that the material properties of the BiVO4 can be engineered by the thickness of the SnO2 layer underneath. Furthermore, during the synthesis of a solution processed BiVO4, chemical composition of BiVO4 or Mo-doped BiVO4 films has a significant impact on its PEC performance. We will discuss in detail how the solution processed BiVO4 can be optimized through these strategies. |
