CuInS2 semiconductor were synthesized by regulating Cu/In molar ratio via a hot solvent method. Different Cu/In molar ratio in reaction system had significant influence on the BET surface area, charge separation and photocatalytic activity of CuInS2. The CuInS(2 )with optimal Cu/In ratio of 1:1.5 exhibits the most efficient charge separation and transfer, leading to the highest photocatalytic activity. The mineralization efficiency of pharmaceutical wastewater by CuInS2 (Cu:In = 1:1.5) was 67.5% in 6 h, and CuInS2 (Cu:In = 1:1.5) exhibited high stability, indicating that CuInS2 has a promising prospect in real pharmaceutical wastewater treatment. (C) 2018 Elsevier B.V. All rights reserved.