Pd Nanoparticle-Modified\nBiOBr/CdS S‑Scheme\nPhotocatalyst for Enhanced Conversion of CO<sub>2</sub>

S-scheme heterojunction photocatalyst-coupled plasma-resonance\neffect can enhance the response range and absorption of light and\ncharge transfer, and, at the same time, obtain strong redox ability,\nwhich is an effective way to improve CO<sub>2</sub> conversion. In\nthis work, plasma S-scheme heterojunctions of Pd/BiOBr/CdS with heterogeneous\ninterfaces have been successfully constructed by a simple hydrothermal\nmethod. The possible reaction mechanism was proposed by in situ infrared,\nultraviolet–visible spectroscopy (UV–vis), electron\nparamagnetic resonance (ESR), density functional theory (DFT), and\nelectrochemical techniques. It was proved that the plasma S-scheme\nheterojunction can enhance the charge separation efficiency and improve\nthe photocatalytic activity. When the loading ratio is Pd<sub>0.6</sub>-10%-BiOBr/CdS, it has the best performance, and the CO yield is\n30.24 μmol/g, which is 15 and 30 times that of pure BiOBr and\nCdS, respectively. The results show that with the strong absorption\nof photon energy and the special electron transfer mode of S-scheme\nheterojunction, the charge can be effectively separated and transferred,\nand the photocatalytic activity is significantly improved. This study\nprovides a useful strategy for charge transfer kinetics of plasma\nS-scheme heterojunction photocatalysts.