Metallic Bi and oxygen vacancy dual active sites enable efficient oxygen activation: Facet-dependent effect and interfacial synergy

Surface atomic arrangement and coordination of different crystal facets significantly affect the catalytic reactivity of photocatalysts. By modulating the solvent environment, we developed a one-step solvothermal route to synthesize a series of BiOBr nanosheets with different dominating facets ((001) and (010)) and simultaneously decorated metallic Bi and oxygen vacancies (OVs) on the identified preferred facets ((010)). The resulting Bi/OV-BiOBr-(010) outperform BiOBr-(010) with mono OVs, bare BiOBr-(010), and other well-known photocatalysts in both O2 activation and pollutant degradation under both same catalyst loading and optical thickness conditions. The synergistic effects of the Bi-OV dual active sites in O2 adsorption-activation and charge separation-transfer were confirmed by experimental characterization and DFT calculation. This study highlights the facet-dependent synergy of plasmonic metal-defect dual active sites and shed light on the rational design of photocatalysts for more efficient O2 activation and refractory pollutant degradation.