A novel core-shell Z-scheme heterojunction In2O3@BiFeO3 with broad spectrum response for enhanced photocatalytic degradation of tetracycline

Abstract

Photocatalysis is proven as a desirable technology for elimination of the tetracyclines pollutant from wastewater. Herein, a novel core-shell Z-scheme heterojunction In2O3@BiFeO3 was, for the first time, fabricated via facile hydrothermal method to effectively eliminate tetracycline in wastewater. The prepared photocatalysts were characterized by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), UV–vis spectroscopy and so on. The photocatalytic performance of the prepared samples was evaluated by photo-degradation of tetracycline (TC) under visible light. TC degradation results demonstrated that the as-prepared In2O3@BiFeO3 obeyed the pseudo-first-order kinetics and exhibited a higher photocatalytic rate of 0.01173min−1 that was approximately 2.97 and 14.4 folds those of the raw BiFeO3 and In2O3, respectively. Additionally, In2O3@BiFeO3 possessed high stability during five consecutive cycles. The core-shell structure and the photosensitization of BiFeO3 significantly improved light-absorption in the entire visible region. The enhanced photocatalytic activity is attributed to the improved light harvesting and the effective separation of photogenerated electron-hole pairs due to the formation of core-shell Z-Scheme heterojunction. Due to the well-matched band position of In2O3 and BiFeO3, •OH, •O2− and h+ all act as primary reactive species in TC degradation. This research provides a new strategy to construct the promising visible-light-driven photocatalyst for environmental remediation.