Construction of ZnS/Cu₂SnS₃ heterojunction for photocatalytic degradation of organic pollutant methylene blue

Photocatalytic degradation has proven to be effective in addressing the increasing organic pollution, and materials associated with it are worthy to be deep exploration. In this study, the composite materials based on ZnS and Cu2SnS3 were prepared in a two-step method, the phases, morphologies, UV-vis adsorption, and bang gaps were characterized, and the photocatalytic activities were also investigated on methylene blue degradation. Results showed Cu2SnS3 (CTS) was the highly crystalline tetragonal phase with a lamellar shape while ZnS was agglomerated particles with poor crystallinity. With increased ZnS amounts, the heterojunction formed by ZnS dotted on CTS changed into the one that ZnS fully coated on CTS. Compared with ZnS or CTS alone, the ZnS/CTS heterojunctions received a wider visible light adsorption range and enhanced adsorption intensity, exhibited superior photocatalytic efficiencies under the actions of h(+), (OH)-O-center dot, and O-center dot(2)- free radicals, and the one prepared with 0.5 mmol ZnS performed best.