Solar light-driven photocatalytic hydrogen evolution over ZnIn(2)S(4) loaded with transition-metal sulfides

A series of Pt-loaded MS/ZnIn(2)S(4) (MS = transition-metal sulfide: Ag(2)S, SnS, CoS, CuS, NiS, and MnS) photocatalysts was investigated to show various photocatalytic activities depending on different transition-metal sulfides. Thereinto, CoS, NiS, or MnS-loading lowered down the photocatalytic activity of ZnIn(2)S(4), while Ag(2)S, SnS, or CuS loading enhanced the photocatalytic activity. After loading 1.0 wt.% CuS together with 1.0 wt.% Pt on ZnIn(2)S(4), the activity for H(2) evolution was increased by up to 1.6 times, compared to the ZnIn(2)S(4) only loaded with 1.0 wt.% Pt. Here, transition-metal sulfides such as CuS, together with Pt, acted as the dual co-catalysts for the improved photocatalytic performance. This study indicated that the application of transition-metal sulfides as effective co-catalysts opened up a new way to design and prepare high-efficiency and low-cost photocatalysts for solar-hydrogen conversion.