ZIF-67/Zn075Cd0.25S heterojunction for efficient photocatalytic hydrogen production: Lignin-carbon quantum dots synergistic enhanced charge separation and hydrogen diffusion.

Based on the carbon quantum dots (CQDs) derived from waste lignin, this study coupled them with visible light-responsive Zn0.75Cd0.25S (ZCS) and the catalytically active ZIF-67 to construct the ternary composite photocatalyst ZIF-67/ZCS/CQDs, aiming to suppress carrier recombination and broaden the light absorption range. The characterization results show that this composite system effectively integrates the catalytic activity of ZIF-67, the visible light absorption characteristics of ZCS, and the charge transfer advantages of CQDs, forming an efficient charge transfer channel. This design significantly enhances the separation and migration efficiency of photogenerated carriers, thereby greatly improving the performance of photocatalytic hydrogen production. This research provides new ideas for the design of highly efficient photocatalysts and also opens up new avenues for the high-value utilization of waste biomass.