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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 BiO 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. [ABSTRACT FROM AUTHOR]

Strong coupling between the Si photocathode and a low‐cost cocatalyst is of great significance for enhancing the photoelectrochemical hydrogen evolution. Here, a facile method is proposed to in situ assemble amorphous MoSx (a‐MoSx) thin‐film onto a single crystal p‐Si through a self‐reduction mechanism to achieve strong coupling. In the process of self‐reduction, the (MoS4)2− anion is reduced to form a‐MoSx by the oxidation of H–Si to form SiOx, which is etched further to form H–Si again in the hydrofluoric aqueous solution. The cyclic formation of H–Si and SiOx plays a decisive role in the continuous deposition of a‐MoSx and provides a unique way to synthesize metal sulfides. Such a‐MoSx/p‐Si photocathode exhibits an excellent activity, achieving the optimal onset potential of +0.31 VRHE and the current density of −28.2 mA cm−2 at 0 VRHE with a Faradaic efficiency close to 98%, respectively, outperforming the thermally exfoliated 2H‐MoS2 and 1T‐MoS2 cocatalysts on p‐Si and comparable to the previous studies. The proposed method for uniform deposition at room temperature is simple to carry out and can be used for fabricating other Si‐based photoelectrodes. [ABSTRACT FROM AUTHOR]