| 초록 |
Monoclinic bismuth vanadate (BiVO4) is a promising photoanode for solar-driven water splitting due to its narrow band gap (~2.4 eV) and proper band edges for oxygen evolution reaction (OER). However, due to its poor electrical conductivity and slow kinetics of the OER, the reported efficiency with a BiVO4 based photoanode is significantly less than those expected theoretically. The approaches that have been typically used to resolve these issues include the decoration of co-catalysts acting as an electron scavenger such as AgNO3, FeOOH, NiOOH, or Co-Pi, and the introduction of a buffer layer such as tin oxide (SnO2) for selective transport of electrons towards the bottom electrode. Here, we investigate the effects of the thickness of a SnO2 buffer layer which is prepared by a solution method on the growth of BiVO4 and its photoelectrochemical (PEC) performance. The thickness of the SnO2 buffer layers is easily controlled by altering the molar concentration of the SnO2 precursor solution. Interestingly, during the synthesis of BiVO4, the morphology of BiVO4 layers can be changed by varying the SnO2 thickness. Additional materials characterization as well as PEC measurements of BiVO4 photoanodes with a varying thickness of the SnO2 will be presented. |
