BiOBr/MXene/gC3N4 Z-scheme heterostructure photocatalysts mediated by oxygen vacancies and MXene quantum dots for tetracycline degradation: Process, mechanism and toxicity analysis

The rapid recombination rate of photogenerated charges make the rational design of high-performance stable photocatalysts challenging. Herein, the features of heterojunctions, oxygen vacancies (OVs), and MXene quantum dots (MQDs) were simultaneously collected in CBM (gC 3 N 4 /BiOBr/MXene) using a simple solvothermal method for the first time. OVs promoted the chemisorption of O 2 , MQDs not only accelerated electron transport but also promoted a photogenerated charge to selectively generate singlet oxygen, 99% of the tetracycline hydrochloride (TC-HCl) was degraded by CBM within 30 min under visible light irradiation. Thirteen intermediates and possible photocatalytic degradation pathways were proposed. It was discovered that CBM is nontoxic to the environment but can swiftly produce an excellent antibacterial effect when exposed to visible light irradiation. This research provides fresh insights into the effective removal of organic pollutants from water by combining cutting-edge defect engineering and quantum dot doping technology in photocatalytic heterojunctions.