Construction of a novel BiOCl/Bi2MoO6/MIL-125(Ti) with Z-scheme and II-type dual-functional heterojunctions for enhancing photocatalytic degradation of tetracycline under visible light irradiation

The overuse of antibiotics, coupled with inadequate wastewater treatment, has led to widespread environmental contamination, posing significant risks to ecosystems and public health. In this study, a novel BiOCl/Bi₂MoO₆/MIL-125(Ti) heterojunction catalyst featuring a Z-scheme and II-type dual-functional junctions was prepared via a two-step solvothermal method and employed for the degradation of tetracycline (TC). The synthesized samples were thoroughly characterized by XRD, SEM, BET, TEM, and UV–vis spectroscopy. The results indicate that the incorporation of BiOCl and Bi₂MoO₆ effectively tunes the band structure of MIL-125(Ti), enhancing its visible-light absorption. Moreover, the formation of the heterojunction interfaces significantly suppresses recombination of photogenerated charge carriers, thereby improving photocatalytic performance. Under visible-light irradiation, the BiOCl/Bi₂MoO₆/MIL-125(Ti) catalyst generates reactive radicals (·OH and ·O₂⁻), enabling efficient degradation of TC with a removal efficiency of 95.71 %. The synergistic effect of the Z-scheme and II-type heterojunctions plays a crucial role in the efficient photocatalytic degradation of TC. This study provides new insights into the degradation mechanisms of bifunctional heterojunctions and presents a promising strategy for designing high-performance photocatalysts for tetracycline degradation.