Controlled synthesis of 2D hetero-structured FeS2/rGO hybrids catalyst for visible-light-driven water oxidation

Abstract Pyrite (FeS2) is a promising photocatalyst because of its high optical absorption coefficient, suitable band gap and low cost. However, the low conductivity and weak stability of FeS2 limits its application. Herein, two-dimensional (2D) hetero-structured FeS2/reduced graphene (FeS2/rGO) photocatalyst was synthesized by a facile sodium-oleate-assisted two-phase solvothermal method. The optimized FeS2/rGO hybrids possessed excellent initial conversion frequency (TOF, 10.96 μmolO2·molmetal-1·s-1) and oxygen evolution amount (21.2 μmol), which was 2.5 times higher than of pure FeS2. Further studies revealed that the excellent catalytic property was attributed to the 2D heterojunction between FeS2 and rGO, which improved the optical adsorption of the hybrids and accelerated the rapid transfer of photogenerated charges from FeS2 surface to water molecules. The FeS2/rGO hybrids remained stable even after three runs photocatalytic reaction under the strong oxidation conditions. This study provides a facile strategy for the design of FeS2/rGO hybrids as a highly efficient water oxidation catalyst, improving the development of solar energy conversion.