Preparation and Visible Light Catalytic Performance of Fe3O4/Ag/BiVO4/Sepiolite Composites

Abstract To increase specific surface area and light utilization of photo‐catalysts, a series of Fe 3 O 4 /Ag/BiVO 4 /sepiolite composites with different Fe 3 O 4 contents were synthesized via co‐precipitation. The structure, composition, and optical properties of these composites were characterized using X‐ray diffraction (XRD), nitrogen adsorption and desorption (BET), UV‐Vis diffuse reflectance spectroscopy (UV‐Vis DRS), and fluorescence spectroscopy (PL). The photo‐catalytic activity of the composites was further evaluated using rhodamine B as a model for photo‐catalytic degradation. The results revealed that the composites with optimal Fe 3 O 4 loading exhibited the narrowest bandgap width, approximately 2.13 eV, and the highest electron‐hole pair separation efficiency. Rhodamine B could be almost completely degraded within a short illumination time in the presence of the Fe 3 O 4 /Ag/BiVO 4 /sepiolite composites. The degradation mechanism of rhodamine B was proposed to involve the improvement of the photo‐catalytic activity of the resulting composites by the Fe 3 O 4 and the Z‐type heterojunction structure. Additionally, the composites could be recycled and reused multiple times, making them an environmentally friendly and sustainable option.