fig1

Figure 1. (A) UV-Vis DRS and (B) a schematic illustration of the band structure of FeVO₄; (C) Time courses of the OER over FeVO₄ photocatalysts loaded with CoO_x cocatalyst in different methods; (D) Time course of the HER over FeVO₄ photocatalyst loaded with Pt cocatalyst. Reaction conditions of (C): 0.1 g of photocatalyst (0.8 wt% Co is loaded); 100 mL of AgNO₃ aqueous solution (50 mM); 0.1 g of La₂O₃; 300 W Xe lamp with a cut-off filter (λ ≥ 420 nm). Reaction conditions of (D): 0.1 g of photocatalyst (1.0 wt% Pt is loaded); 100 mL of ascorbic acid aqueous solution (10 mM); 300 W Xe lamp with a cut-off filter (λ ≥ 420 nm). UV-Vis DRS: Ultraviolet-visible diffuse reflectance spectroscopy; OER: oxygen evolution reaction; HER: hydrogen evolution reaction.