Ball-milling fabrication of n-p heterojunctions Bi4O5Br2/α-MnS with strengthened photocatalytic removal of bisphenol A in a Z-Scheme model

Abstract

In this investigation, α-MnS with a large magnetic moment was typically selected to modify Bi4O5Br2 to produce a train of binary n-p heterojunction composites Bi4O5Br2/α-MnS (BMS) through a facile mechanical ball-milling manner. These achieved composites were subsequently subjected to physicochemical properties analyses. It was confirmed that both expected components were present and integrated into heterojunction structures. An endocrine disruptor bisphenol A (BPA) was typically selected as a target contaminant to estimate photocatalytic degradation efficiency under visible light. Under the identical condition, composites BMS exhibited obviously improved degradation efficiencies. Notably, the best catalog, composite BMS0.05, displayed the best catalytic outcome with an apparent reaction rate constant of 2.67 times that of Bi4O5Br2, primarily ascribed to the strengthened visible-light absorption, suitable phase composition, and boosted generation of reactive radicals caused by efficient carries redistribution and segregation along the appropriate band alignment. In addition, some reaction parameters were varied to optimize such a photocatalytic system. Moreover, degradation pathways were speculated through intermediates detection. Eventually, a rational Z-scheme photocatalysis mechanism was proposed in the light of capture experiments and band structure estimation.