Figure 7

(a) Time courses of photocatalytic H₂ evolution from Na₂SO₃, Na₂S aq. solution on WO₃, WO_3–x, Zn_0.3Cd_0.7S, WO₃/Zn_0.3Cd_0.7S and WO_3–x/Zn_0.3Cd_0.7S heterostructure, (b) Time-cycle photocatalytic hydrogen production over WO_3–x/Zn_0.3Cd_0.7S heterostructure under visible–light illumination (λ ≥ 420 nm).