Rapid carrier extraction and d-band center regulation of Pd-ZnIn2S4 for efficient photocatalytic water splitting

Addressing the dynamic behavior of carrier extraction and the regulation of the metal d‐band center is crucial yet remains a significant challenge in the photocatalytic water-splitting process. In this study, we successfully incorporated different amounts of Pd into the ZnIn₂S₄ lattice using a one-pot oil bath method. This approach facilitated efficient carrier extraction and effective modulation of the d‐band center by introducing numerous S-defect sites. Furthermore, the coupling of 2.79 wt% Pd optimized the adsorption free energy of ZnIn₂S₄ for the crucial hydrogen evolution intermediate (*H). As a result, the solar efficiency, specific surface area, hydrophilicity, and carrier separation efficiency of ZnIn₂S₄ were all enhanced. Illuminated by a 300 W xenon lamp, the photocatalytic hydrogen evolution rate achieved 2.31 mmol/g/h, exhibiting a quantum efficiency of 4.56 % at 420 nm. These findings contribute to overcoming the dynamic bottlenecks in photocatalytic water splitting, thus enhancing the efficiency of solar energy conversion into clean energy sources.