Photochemical preparation of S-vacancies CuS hollow microspheres for cyclic adsorption of rhodamine B

Abstract

Enhancing adsorption interaction between absorbate and photocatalysts can shorten the charge transfer path for the hole and electrons toward highly efficient photocatalytic degradation of organic dye pollutants. Copper sulfide (CuS) is often used as a photocatalyst but insufficient adsorbed sites, limiting the photocatalytic performance. Herein, we developed a facile photochemical approach to fabricate S vacancies CuS (Sv-CuS) hollow microspheres with various crystalline structures by controlling the UV irradiation light intensity in crystal growth. CuS with moderate crystallinity and Sv shows a high Rhodamine B (RhB) adsorption capacity of 21.72 mg·g−1. The adsorption results demonstrate that the pseudo-second kinetics model, multiple steps, and Langmuir isotherms model match well the RhB uptake behavior. The density functional theory calculation shows that the adsorption process is energetically favorable and there is chemically electrostatic interaction between Sv-CuS/RhB. Further, the Sv-CuS can be regenerated by removing most adsorbed RhB molecules on the surface using photocatalytic degradation technology. The construction of Sv-CuS created by photochemical reaction with remarkable adsorption efficiency and reusability may provide a new insights into the rational design of adsorbent and photocatalyst in wastewater treatment and environmental catalytic technology.

Keywords

• S vacancies CuS
• Controllable crystal structure
• Rhodamine B
• Adsorption
• Adsorbent regeneration