BiVO4 was fabricated on a fluorine-doped tin oxide (FTO) substrate with SnO2 hole blocking layer following previous literature. First, 0.1 M of SnCl2•2H2O was dissolved in isopropyl alcohol with stirring for 1 h and kept for 1 day under ambient conditions. A SnO2 layer was then spin-coated onto a cleaned FTO substrate at 3000 rpm for 20 s, followed by annealing at 500 °C for 1 h under ambient air conditions. BiVO4 was synthesized on the SnO2-coated FTO substrate using a metal-organic deposition method. A 0.5 M of Bi(NO3)3•5H2O in acetic acid and a 0.27 M of VO(acac)2 in methanol (aged for 3 days) were prepared, respectively. After dissolving each precursor in solvents, the V solution was added to the Bi solution with 1.1 Bi/V molar ratio. The mixed precursor solution was spin-coated on the substrate at 2000 rpm for 20 s, and the annealing process was carried out at 480 °C for 20 min under air condition. The spincoating process was repeated to obtain the desired thickness of BiVO4.