Synergistic effect of lignin-derived carbon dots and CdS for enhanced visible-light hydrogen generation
摘要
The development of efficient and sustainable photocatalysts is crucial for addressing the global energy crisis. This study focuses on the design and preparation of a novel heterojunction photocatalyst composed of cadmium sulfide (CdS) nanoparticles and carbon quantum dots (CQDs) derived from lignin, aimed at significantly enhancing photocatalytic hydrogen production. Using methanol as a solvent, lignin-based CQDs were synthesized via a hydrothermal method and in situ loaded onto CdS to form a closely contacted heterointerface. The optimized CdS/CQD composite with a nominal CQD loading of 1.0 wt% (denoted as CdS/CQDs-1) exhibited a markedly improved hydrogen evolution rate of 1.504 mmol h⁻1 g⁻1 under simulated sunlight, which is approximately 1.45 times higher than that of pure CdS, with excellent stability over multiple cycles. Mechanistic investigations revealed that CQDs act as efficient electron acceptors, facilitating charge separation and reducing electron–hole recombination. This work not only demonstrates a green, biomass-derived strategy for constructing high-performance photocatalysts but also provides new insights into the design of sustainable heterojunction systems for solar energy conversion.