Constructing Cd0.5Zn0.5S/Bi2WO6 S-scheme heterojunction for boosted photocatalytic antibiotic oxidation and Cr(VI) reduction

Abstract

The development of distinguished photocatalysts with high photo-carrier disassociation and photo-redox power for efficient elimination of pollutants in water is of great significance but still a grand challenge. Herein, a novel Cd_0.5Zn_0.5S/Bi₂WO₆ S-scheme heterojunction was built up by integrating Cd_0.5Zn_0.5S nanoparticles on Bi₂WO₆ microspheres via a simple route. The S-scheme charge transfer mode substantially boosts the high-energetic electrons/holes spatial detachment and conservation on the Cd_0.5Zn_0.5S (reduction) and Bi₂WO₆ (oxidation), respectively, as well as effectively suppresses the photo-corrosion of Cd_0.5Zn_0.5S, rendering Cd_0.5Zn_0.5S/Bi₂WO₆ photocatalysts with superior redox ability. The optimal Cd_0.5Zn_0.5S/Bi₂WO₆ heterojunction achieves exceptional visible-light-driven photocatalytic tetracycline degradation and Cr(VI) reduction efficiency, 3.2 (1.9)-time and 33.6 (1.6)-time stronger than that of neat Bi₂WO₆ (Cd_0.5Zn_0.5S), while retaining the superior stability and reusability. Quenching test, mass spectrometry analysis, and toxicity assessment based on Quantitative Structure Activity Relationships. calculation unravel the prime active substances, intermediates, photo-degradation pathway, and intermediate eco-toxicity in photocatalytic process. This research not only offers a potential photocatalyst for aquatic environment protection but also promotes the exploration of novel and powerful chalcogenides-based S-scheme photocatalysts for environment protection.