Morphological evolution of hierarchical Bi2Se3/BiOBr nanostructures and enhanced activity for p-nitrophenol reduction by NaBH4

Abstract

An emerging Bi₂Se₃/BiOBr composite with a flower-like microsphere structure has been synthesized by a solvothermal method using CTAB as a template agent. It is found that the obtained Bi₂Se₃/BiOBr composite showed a good catalytic performance for the hydrogenation of p-nitrophenol. The catalytic times of the conversion of up to 90% for the Bi₂Se₃/BiOBr composite, Bi₂Se₃ and BiOBr are about 5.0, 12.5 and 15.0 min, respectively. The enhanced catalytic activity of the Bi₂Se₃/BiOBr composite results from a synergistic effect of Bi₂Se₃ and BiOBr, probably owing to the unique structure, and the combination promotes the transfer of electrons. A self-assembling growth mechanism of the Bi₂Se₃/BiOBr composite is proposed by observing the morphology and composition of the products at different times. It is found that BiOBr microspheres first formed, then BiOBr microspheres gradually reacted with selenium powder to grow the Bi₂Se₃/BiOBr composite.