Construction of a novel Bi-MOF/BiVO4 heterojunction with enhanced visible light photocatalytic performance

Abstract

The bismuth-based organic frameworks (Bi-MOFs) have low toxicity, low cost and good chemical stability, and show certain application potential in the photocatalytic removal of organic pollutants without environmental hazards. To cope with its defects of a narrow light absorption range and large band gap in the photocatalytic process, bismuth terephthalate (BiBDC) and BiVO4 were used in this study to construct the BiBDC/BiVO4 heterojunction by a hydrothermal method. In this way, a stable material that can efficiently remove organic pollutants from water under visible light irradiation without adding oxidants was obtained. The photocatalytic performance of the obtained BiBDC/BiVO4 on tetracycline (TC), ciprofloxacin (CIP) and bisphenol A (BPA) was significantly better than that of pure BiBDC and BiVO4. The improved performance is attributed to the broadened optical absorption range and accelerated separation of photogenerated electrons and holes by the heterojunction. BiBDC/BiVO4 also showed excellent reusability and stability. The analysis of the photocatalysis mechanism revealed that h+ and·O2- could strongly affect the degradation of TC in the studied system. In addition, BiBDC/BiVO4 has great potential for practical application, because its photocatalytic activity to remove TC remains efficient under the influence of common environmental factors (pH value, inorganic ions, organic matter, water source). It is expected that this study will deepen the understanding of the BiBDC/BiVO4 heterojunction structure for the removal of organic pollutants and provide strategies for the application of photocatalytic technology in industry.