Double-template-regulated bionic mineralization for the preparation of flower-like BiOBr/carbon foam/PVP composite with enhanced stability and visible-light-driven catalytic activity

Abstract A novel flower-like BiOBr/carbon foam (CF)/polyvinylpyrrolidone (PVP) composite with a narrow bandgap was fabricated by double-template-regulated bionic mineralization using CF as a hard template and PVP as a soft template. The structure, morphology, and optical properties of the BiOBr/CF/PVP composite were systematically characterized. The photocatalytic activity of the samples was investigated based on the catalytic degradation efficiency of rhodamine B (RhB). The results indicated that the photocatalytic performance of the BiOBr/CF/PVP composite with an optimal mineralization time of 10 h was superior to those of BiOBr/CF, BiOBr/PVP, and pure BiOBr. The enhanced activity of the BiOBr/CF/PVP composite could be attributed to the good hydrophilic properties, unique three-dimensional flower-like structure, improved visible-light absorption, effective separation of photogenerated electron-hole pairs, and an increase in (110)/(102) crystal plane ratio of BiOBr. In addition, the possible degradation pathways of RhB photocatalyzed by BiOBr/CF/PVP were analyzed by tracking the degradation by-products. After consecutive degradation reactions, the catalytic performance and structure of BiOBr/CF/PVP exhibited no remarkable changes. Notably, the BiOBr/CF/PVP composite exhibited good reusability, excellent stability, and high adsorption-photocatalytic properties and could be easily separated from the reaction system for recycling.