Cu2-xSe@CuInSe2 hollow cage catalyst for efficient visible light degradation of antibiotics based on electric field co-regulation of charge directional transport

Abstract

The design and construction of a new hollow caged selenide for the degradation of refractory antibiotics in surface water is an effective way to improve the efficiency of solar energy utilization, but early photocatalysts often face problems such as high recombination efficiency of photogenerated carriers and slow transport kinetics. In this study, an asymmetric Cu_2-xSe nanocomposite catalyst modified with hollow caged structure CuInSe₂ was successfully constructed, in which the empty structure promotes the rapid directional transport of photogenerated charges through the synergistic effect of bulk electric field (BEF) and local surface electric field (LSEF). Photogenerated electrons are directed from the [CuSe] region through the [InSe] region and migrate directionally to the hollow caged Cu_2-xSe surface. In the Cu_2-xSe@CuInSe₂–0.3 catalyst system, the degradation efficiency of tetracycline (TC) can reach 95.8 % within 30 min, and the rate constant is 0.11 min⁻¹, which is 8.5 times and 12.6 times that of Cu_2-xSe and CuInSe₂, respectively. The characterization results and density functional theory (DFT) calculations show that the photocatalytic activity driven by visible light is significantly improved by directionally guiding the charge transport path and enhancing the light absorption properties, providing a new idea for the development of refractory wastewater treatment and wheat growth environment.