Region-specific defect engineering of Bi<sub>2</sub>W<sub>1-x</sub>O<sub>6-γ</sub> induces nanoscale electric fields and surface active-sites for enhanced visible-light oxidation of salt-lake flotation agents.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 41315373.
- Also identified by DOI 10.1038/s41467-025-66466-5 and PMC identifier 12722310.
- Licence recorded as CC BY.
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Abstract
Breaking the limitations of conventional defect engineering, this work pioneers region-specific dual-defect engineering in Bi<sub>2</sub>WO<sub>6</sub>. 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 Bi<sub>2</sub>WO<sub>6</sub>. Additionally, the generation of reactive species ( <math xmlns="http://www.w3.org/1998/Math/MathML"><mo>⋅</mo> <msubsup><mrow><mi>O</mi></mrow> <mrow><mn>2</mn></mrow> <mrow><mo>-</mo></mrow> </msubsup> </math> , <math xmlns="http://www.w3.org/1998/Math/MathML"> <mmultiscripts><mrow><mi>O</mi></mrow> <mrow><mn>2</mn></mrow> <none></none> <mprescripts></mprescripts> <none></none> <mrow><mn>1</mn></mrow> </mmultiscripts> </math> , and h⁺) is significantly boosted by factors of 8.98, 5.55, and 20.02, respectively, highlighting the material's remarkable reactivity. Photoelectrochemical analyses reveal a remarkable 290% increase in charge separation efficiency. This enhancement is further supported by an improved O<sub>2</sub> adsorption capacity, which promotes the formation of reactive oxygen species involved in the degradation process. Impressively, the engineered Bi₂W₁₋ₓO₆₋ᵧ exhibits outstanding performance in real-world industrial wastewater treatment under solar irradiation, demonstrating its practical viability. Overall, this work establishes a new paradigm in photocatalysis by integrating precise nanoscale defect engineering with enhanced electrostatic modulation.