Reinforced Hole Trapping in S‐Scheme Photoharvesters for Markedly Enhanced Photocatalytic Hydrogen Evolution and Nitrogen Fixation

Abstract The S‐scheme heterojunction exerts a profoundly positive influence on enhancing carrier separation efficiency and redox capability. However, there are few reports on accelerating the reaction rate of photogenerated charge carriers, particularly the consumption rate of photogenerated holes in S‐scheme heterojunction. Herein, an in situ construction strategy is employed to construct ultra‐small nonprecious metal NiO (≈2 nm) on an S‐scheme heterojunction. By incorporating ultra‐small NiO into S‐scheme heterojunctions, photocatalytic hydrogen production performance is significantly improved by 380 times, and nitrogen fixation performance is enhanced by 20 times. Density function theoretical (DFT) calculations, in situ X‐ray photoelectron spectroscopy (in situ XPS), and in situ Diffuse Reflectance Infrared Fourier Transform Spectroscopy (in situ DRIFTS) characterization results indicate that the incorporation of ultra‐small NiO into S‐scheme heterojunctions can not only enhance the separation efficiency of photo‐generated carriers and the redox ability of S‐scheme heterojunctions but also further promote the consumption rate of photo‐generated holes by sacrificial agents, thereby achieving a secondary enhancement in carrier separation efficiency. Therefore, the photocatalytic performance of hydrogen (H₂) production and nitrogen (N₂) fixation is markedly improved. The successful execution of this work provides a novel approach to material structure design, offering valuable insights for the development and performance improvement of high‐performance heterojunction materials.