One-step in situ hydrothermal fabrication of octahedral CdS/SnIn4S8 nano-heterojunction for highly efficient photocatalytic treatment of nitrophenol and real pharmaceutical wastewater

Octahedral CdS/SnIn4S8 nano-heterojunctions were fabricated by a facile and simple one-step in situ hydrothermal method, and the molar ratio of CdS to SnIn4S8 was optimized. The optimal (0.5:1)CdS/SnIn4S8 heterojunctions exhibit the highest visible-light photocatalytic activity with 97.1% degradation efficiency of 2-nitrophenol in 120 min, which is much higher than those of individual CdS and SnIn4S8. The enhanced photocatalytic performance could be attributed to the effective separation and transfer of photogenerated charges originating from the well-matched band gap structures. Of special significance is that (0.5:1)CdS/SnIn4S8 can effectively mineralize 2-nitrophenol and real pharmaceutical wastewater. Moreover, CdS/SnIn4S8 nano-heterojunctions show excellent reusability in five cycles due to the stable surface composition and chemical valence state.