Visible-light-driven Z-scheme ZnTe/WO3 heterojunction for simultaneous elimination of tetracycline and Cu(II)

Abstract

Z-Scheme heterojunction photocatalysts can effectively suppress the recombination of charge carriers while maintaining high redox capacity. In this study, ZnTe/WO₃ (ZW) Z-scheme heterojunction photocatalysts were synthesized using a hydrothermal method, and a series of photocatalytic materials were prepared for the simultaneous removal of tetracycline (TC) and Cu(II) from water. The physicochemical and photoelectrochemical properties of the catalytic materials were characterized through various methods, including SEM, XRD, XPS, and others. The experimental results indicate that the ZW-10 % composite material exhibits the most significant removal efficiency for pollutants. Within 150 min of visible light irradiation, the removal rates for TC and Cu(II) reach 73.8 % and 73.3 %, respectively, representing a substantial improvement compared to individual ZnTe and WO₃. Free radical capture experiments and electron spin resonance analysis reveal that ·O₂⁻ and ·OH are the key reactive species responsible for TC oxidation, while electrons (e⁻) dominate the reduction of Cu(II).