Construction of PANI@V₂O₅-ZnIn₂S₄ Z-scheme heterojunction photocatalysts for highly effective degradation of industrial dyes and antibiotics

From an environmental protection, the highly effective photodegradation of organic dyes and antibiotics in wastewater needs to be solved expeditiously. Fortunately, the construction of Z-scheme heterojunction for photocatalytic degradation is considered to be an effective method. In this paper, after the fabrication of V₂O₅ by calcination and loading of PANI on its surface by aniline polymerization, a novel PANI@V₂O₅-ZnIn₂S₄ composite photocatalysts prepared by one-pot synthesis method and used for the degradation of industrial dyes (crystalline violet, Congo red) and antibiotics (tetracycline-TC). Under the optimal photodegradation conditions, the 30 wt% PANI@V₂O₅-ZnIn₂S₄ heterojunction photocatalysts resulted in more than 95 % degradation of CR, CV and TC solutions after 32 min of irradiation. The optimal photodegradation conditions of the simulated pollutants in real aqueous environments catalyzed by the as-synthesized photocatalysts were explored via response surface methodology (RSM). Multiple material characterization techniques, such as FESEM, HRTEM, XPS valence band spectrum, photoelectrochemistry, radical trapping experiments and EPR tests verified the existence of Z-scheme heterojunction. Especially, the coating of conductive PANI on the V₂O₅ surface can further improve the separation and transfer efficiency of photogenerated charge carriers, thereby enhancing the photocatalytic activity of the semiconductor photocatalyst. This study will provide a robust option for the design and construction of Z-scheme heterojunctions photocatalysts for environmental pollution remediation.