Region-specific defect engineering of Bi2W1-xO6-γ induces nanoscale electric fields and surface active-sites for enhanced visible-light oxidation of salt-lake flotation agents
摘要
Breaking the limitations of conventional defect engineering, this work pioneers region-specific dual-defect engineering in Bi2WO6. By precisely tailoring tungsten (W) and oxygen (O) vacancies at nanoscale spatial domains-W vacancies at the edges and O vacancies at the center-a spatially asymmetric defect configuration is achieved. This configuration induces a synergistic “defect dipole” effect, amplifying the internal electric field by 2.74 times while simultaneously enriching surface-active sites. As a result, the photocatalytic efficiency is dramatically enhanced, achieving complete oxidation of recalcitrant flotation agents-octadecylamine (ODA) and 4-dodecylmorpholine (DMP)-within just 2 h of visible light irradiation, which is 3.6 times faster than that of pristine Bi2WO6. Additionally, the generation of reactive species (