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 Cd0.5Zn0.5S/Bi2WO6 S-scheme heterojunction was built up by integrating Cd0.5Zn0.5S 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 Cd0.5Zn0.5S (reduction) and Bi2WO6 (oxidation), respectively, as well as effectively suppresses the photo-corrosion of Cd0.5Zn0.5S, rendering Cd0.5Zn0.5S/Bi2WO6 photocatalysts with superior redox ability. The optimal Cd0.5Zn0.5S/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 (Cd0.5Zn0.5S), 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.