Preparation of BiOX Visible-Light Photocatalytic Materials and Optimization of Their NO Degradation Performance
BiOX (X=Cl, Br, I) photocatalytic materials were synthesized via a chemical precipitation method. Their structures and properties were characterized using scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, nitrogen adsorption-desorption, and ultraviolet-visible diffuse reflectance spectroscopy. Results showed that BiOBr exhibits a flower-like nanomicrosphere structure composed of nanosheets, providing a more three-dimensional morphology, larger specific surface area, and moderate light absorption range, resulting in superior visible light absorption. Consequently, BiOBr demonstrated the best photocatalytic degradation of NO under xenon lamp irradiation. The study further investigated the effects of light intensity, NO flow rate, and oxygen presence on the NO degradation performance of BiOBr. Optimal NO removal rate of 58% was achieved under conditions of a light source distance of 15 cm, NO flow rate of 15 mL/min, and in the presence of oxygen. The degradation rate constant for BiOBr was 11×10⁻⁴ min⁻¹, significantly higher than that of BiOCl and BiOI. BiOBr also exhibited good reusability and stability. These findings provide an important experimental basis for the application of BiOBr in the photocatalytic degradation of NO.