For a photoanode, a large overpotential for water oxidation, which limits the solar-to-hydrogen efficiency, may be caused by slow water oxidation kinetics and the recombination of photo-induced electrons and holes. Herein, taking flat and thin BiVO₄ photoanodes as an example, the composite AgO_x/NiO_x electrocatalyst was found to promote not only the water oxidation kinetics, but also the bulk charge separation. As a result, the surface charge injection efficiency (η_inj) and the bulk charge separation efficiency (η_sep) of BiVO₄ photoanodes were improved by the composite AgO_x/NiO_x electrocatalyst. Photo-assisted electrochemical impedance spectroscopy (EIS) was employed to illustrate the significantly reduced surface charge transfer resistance of the BiVO₄/AgO_x/NiO_x sample at the interface between the photoanode surface and the electrolyte. Analysis of the surface potential changes obtained from photo-assisted Kelvin probe force microscopy (KPFM) revealed that the surface photovoltage (SPV) of the BiVO₄/AgO_x/NiO_x photoanode is higher than those of BiVO₄/AgO_x and BiVO₄/NiO_x, representing its large band bending region for bulk charge separation. The open circuit photovoltage (OCP) measurements also demonstrated the superior charge separation ability of the BiVO₄/AgO_x/NiO_x photoanode. The possible working mechanism is that one component of the composite AgO_x/NiO_x electrocatalyst may stabilize the high valence states of the other metal ions, which is beneficial for the formation of water oxidation active sites and the extension of the band bending region.

In situdeveloped MgO nanoparticle segregations are found to serve as effective surface-trap passivators for CuBi₂O₄photocathodes.

This work report a Fe ₃ O ₄ film with inherent chiral structure that effectively promoted OER, owing to its CISS effect on spin aligning intertwined with the capability of half-metallic materials to facilitate the transfer of spin-aligned electrons.

A ZnIn₂S₄ nanoflake-decorated 24-faceted concave MIL-88B(Fe) polyhedron S-scheme system was perfectly created, manifesting simultaneously enhanced photocatalytic cleanup of Cr(vi) and tetracycline.