Lattice Distortion Engineering over Ultrathin Monoclinic BiVO₄ Nanoflakes Triggering AQE up to 69.4% in Visible-Light-Driven Water Oxidation

An efficient water oxidation photocatalyst is imperative for the realization of artificial photosynthesis. Herein, a cooperative strategy is represented that enables 2D structure tailoring and lattice distortion engineering simultaneously over a BiVO₄ photocatalyst for efficient visible-light-driven oxygen evolution reaction (OER). Specifically, the lattice distortion engineering is achieved through the introduction of a sodium (Na⁺) additive during the ion exchange process. Structural characterizations suggest the formation of ultrathin 2D monoclinic BiVO₄ nanoflakes with shrank V-O and elongated BiO bonds. Mechanistic investigations reveal the advantages of ultrathin 2D features for exposing more (010) active facets and shortening the required migration distance for charge carriers to reach the catalytic surface. More importantly, the lattice distortion effect is found to crucially govern the charge carrier dynamics and catalytic surface behavior of BiVO₄ photocatalyst, endowing the optimized sample with an outstanding photocatalytic OER performance triggering up to 69.4% apparent quantum efficiency over Fe³⁺ sacrificial solution. These findings highlight the functional application of morphology and dimensional modification, as well as lattice distortion engineering in synthesizing superior monoclinic BiVO₄ photocatalyst for efficient visible-light-driven water oxidation.