Hydrothermal synthesis of Ca doped β-In2S3 for effective dyes degradation

Abstract

Photocatalytic technology can provide a clean, low-cost and highly efficient path to approach the degradation of azo dyes. Tetragonal β-In2S3 possesses plenty of vacancies, furnishing dopants with abundant interspace, and can be used as a potential photocatalyst for dyes degradation. In this work, Ca was doped into β-In2S3 via a facile one-pot hydrothermal method, which was mainly doped into the crystalline lattices of β-In2S3. Ca doped β-In2S3 revealed better photo-degradation of Methyl Orange (MO) than undoped β-In2S3. The doped Ca ions narrowed band gap and acted as a charge transfer medium, leading to the wider light absorption range and smaller photogenerated charge transfer resistance, respectively. The optimum preparation condition of Ca doped β-In2S3 was determined as holding temperature at 120 °C for 8 h, by which 94.97% of MO was degraded in 20 mins under visible light. The outstanding performance could be owed to the full-grown flaky structure with maximal specific surface area. Based on the experimental results, a possible photocatalytic mechanism for MO degradation over Ca doped β-In2S3 was proposed.