Microwave-assisted preparation of flower-like C60/BiOBr with significantly enhanced visible-light photocatalytic performance

Highlights: • Photogenerated charges separation rate was promoted. • Modification of C₆₀ results in higher surface hydroxyl and higher OVs. • Formation of O₂⁻ in the C₆₀/BiOBr photocatalytic system was accelerated. • Photocatalytic performance has been apparently improved under visible light. The surface properties of photocatalysts significantly affect the photocatalytic activity. For this reason, it is desirable to boost the photocatalytic activity of BiOBr photocatalysts via surface modification. In this demonstration, C₆₀ was used to decorate BiOBr by a microwave hydrothermal method. The flower-like C₆₀/BiOBr photocatalysts, assembled by nanosheets, were carefully examined with structural, optical, and compositional analyses. The results confirm that C₆₀ and BiOBr have been combined together. Because of the existence of synergistic interaction, C₆₀/BiOBr has a higher specific surface area, higher partition and migration of photoinduced carriers, higher surface hydroxyl and O₂⁻ levels, higher oxygen vacancies (OVs) concentration on the catalytic surface. The formation of O₂⁻ was significantly enhanced, confirmed by nitrotetrazolium blue chloride (NBT) measurements. O₂⁻ can be effectively formed by two channels. Based on the photodestruction result of Rhodamine B (RhB), the photocatalytic activity of C₆₀/BiOBr composites was significantly boosted. In light of all the observations and the high electron affinity of C₆₀, separation of photoinduced carriers and a formation mechanism of active free radicals is proposed.