Effect of anisotropic conductivity of Ag 2 S-modified Zn m In 2 S 3+ m ( m = 1, 5) on the photocatalytic properties in solar hydrogen evolution.

3 wt% Ag 2 S/Zn 5 In 2 S 8 (3A/Z5) and 3 wt% Ag 2 S/ZnIn 2 S 4 (3A/Z1) were prepared by a two-step synthesis method. The first-principles calculations revealed that the anisotropic carrier transport property of Zn 5 In 2 S 8 (Z5) is much stronger than that of ZnIn 2 S 4 (Z1). Furthermore, unsynchronized electron and hole transport leads to higher bulk carrier separation efficiency in Z5. After accelerating the surface photocatalytic reaction rate by Ag 2 S modification, the differences between 3A/Z5 and 3A/Z1 in the bulk carrier separation were further enlarged. Photoelectrochemical tests confirmed that the bulk charge separation efficiency of 3A/Z5 is 13.70%, which is 7.4 times higher than 3A/Z1 (1.84%). Because of the high bulk carrier separation efficiency, the 3A/Z5 exhibits a promising photocatalytic hydrogen production rate, reaching 3189 μmol h -1 g -1 . Through intuitive evidence, this work proves that material with stronger anisotropic conductivity has higher bulk carrier separation efficiency, thus has the potential to exhibit high photocatalytic hydrogen production performance.