Construction of bimetallic sulfide/carbon nitride nanocomposites for photocatalytic hydrogen evolution from simulated or natural seawater

ZnCo₂S₄/g-C₃N₄ (ZCS/CNN) nanocomposites were synthesized using the impregnation method and employed for photocatalytic hydrogen evolution from various water sources. The structural, morphological, and photoelectrochemical properties were also thoroughly examined. The optimized 10 % ZCS/CNN nanocomposite demonstrated hydrogen production rates of 358.9 μmol·g⁻¹·h⁻¹ in deionized water, 726.5 μmol·g⁻¹·h⁻¹ in simulated seawater, 656.3 μmol·g⁻¹·h⁻¹ in Bohai seawater, and 516.4 μmol·g⁻¹·h⁻¹ in Zhoushan seawater, outperforming both CNN and ZCS. Besides its exceptional photocatalytic performance, the catalyst exhibited high stability over four cycles. The enhanced activity is primarily attributed to the formation of an S-scheme heterojunction, which lowers reactive impedance, increases photocurrent, and promotes efficient electron-hole separation. The g-C₃N₄-based photocatalytic materials developed in this study hold promise for practical applications in marine hydrogen production.