Anion exchange synthesis of hollow β-In2S3 nanoparticles: Adsorption and visible light photocatalytic performances

Abstract

Crystal phase and morphology control of nano semiconductor materials play a key role on the optimization of their applications. Here, hollow β-In2S3 nanoparticles (NPs) with higher surface area were synthesized via an anion exchange process under a hydrothermal condition. The adsorption capacity and photocatalytic activity of the hollow β-In2S3 NPs were evaluated using Methylene blue (MB) as a model probe both under dark and visible light irradiation. The fast absorption and large adsorption capacity (ca. 157.99 mg/g within 60 min) for MB in the solution were associated to the high specific surface area (324.6 m2/g) of the β-In2S3 NPs as well as the electrostatic interaction between the β-In2S3 and MB molecule, indicating that adsorption approach plays a crucial role for removing MB from solution. After the adsorption reaction, visible light photocatalytic reaction further degrades the remaining MB in the system. The highest removal efficiency of 100 mg/L of MB solution reached 73.4% under dark for 60 min, and further increased to 92.2% after visible light irradiation for 180 min. The Langmuir isotherm model and pseudo-second-order kinetics were used for the model of the adsorption behavior of MB onto the In2S3 sample. The as-prepared hollow In2S3 NPs might be anticipated to be used in dye wastewater treatment.