Enhancing photocatalytic degradation of La-BiVO4 through bidirectional regulation of oxygen vacancy and the Mott-Schottky effect

Abstract

Selective oxidation of photocatalysts is an important reaction, but catalytic capacity and reaction selectivity are usually contradictory. Herein, ultrafine La nanoparticles were introduced to regulate and control the coordination number and environment of Bi, and a catalyst was synthesized with oxygen defects (La-BiVO4) for Rhodamine degradation. Particularly, La-BiVO4 achieved a better reaction rate and selectivity under visible-light irradiation. The results revealed that the degradation rate of Rhodamine by La-BiVO4 reached 94.9 %. Additionally, the characterization and density functional theoretical calculation demonstrated that the Mott-Schottky effect in La-BiVO4 not only changed the BiVO4 electron density and boosted the visible-light-sensitivity, but also hastened the photogenerated charge migration and reduced the energy barrier. This study not only reveals the important role of optimizing single-atom coordination environment in generating free radicals in photocatalytic reactions, but also provides a reasonable degradation strategy for specific pollutants in the environment.