Dual Z-scheme g-C 3 N 4 /GQD/ZnIn 2 S 4 composites with enhanced photocatalytic degradation of xanthate under visible light irradiation

were preferentially adsorbed and activated to generate reactive radicals, whereas xanthate exhibited comparatively weaker adsorption, supporting a radical-dominated degradation pathway. The catalyst retained 92% of its initial activity after five cycles, and post-cycling XPS confirmed good surface chemical stability. This work demonstrates that the CN/GQD/ZIS heterojunction is an effective photocatalytic platform for xanthate removal and supports a GQD-mediated dual Z-scheme charge-transfer pathway in this specific system.