Preparation and Photocatalytic Properties of a Hierarchical BiOCl/BiOF Composite Photocatalyst

International audienceIn this paper, a BiOCl/BiOF composite photocatalyst was obtained via simple mixture method. The as-synthesized sample was characterized by X-Ray Diffraction, Raman scattering, scanning electron microscopy, UV–Vis. diffuse reflectance measurements and electron spin resonance. A strong visible light absorption was observed with a narrowed bandgap compared with single BiOCl due to presence of oxygen vacancies. The photocatalytic activity of the product was evaluated through photocatalytic degradation of Methyl Orange (MO) under UV–Vis. light irradiation. The results show that the BiOCl/BiOF composite photocatalyst exhibits better photocatalytic activity in degrading MO than single BiOCl or single BiOF. The better photocatalytic properties can be attributed to the special band structure of the composite due to a good band matching between BiOF and oxygen vacancy states in BiOCl leading to an effective separation of electron–hole pairs. Moreover, the specific microstructure of the composite plays an active role in the good evaluated photocatalytic performances due to the intimate interfaces between the two parts