NiCoS2/Cd0.5Zn0.5S heterostructures for enhanced photocatalytic hydrogen evolution coupled with value-added conversion of waste plastics

NiCoS 2 /Cd 0.5 Zn 0.5 S Schottky heterojunctions were successfully constructed. • The 5%NiCoS 2 /Cd 0. 5Zn0 .5 S achieved the optimal rate of H 2 evolution and obtained excellent stability. • The 5%NiCoS 2 /Cd 0. 5Zn0 .5 S efficiently produces H 2 by utilizing pretreated plastic waste as feedstock. • The photocatalytic reduction and oxidation mechanisms were explored. The extensive application of plastics has resulted in considerable ecological problems owing to their durability and non-degradability. Solar-light-driven photoreforming offers a promising solution by simultaneously degrading plastic waste and generating clean hydrogen fuel via water splitting. Herein, we design and prepare NiCoS 2 /Cd 0.5 Zn 0.5 S heterostructure photocatalysts for effective solar-light-driven plastic upcycling coupled with hydrogen production. The optimized 5%NiCoS 2 /Cd 0.5 Zn 0.5 S photocatalyst displayed a H 2 evolution rate equal to 55.18 mmol·g −1 ·h −1 , exceeding pristine Cd 0.5 Zn 0.5 S by 16.13 times, and maintained outstanding stability following six recycling tests. Furthermore, the photocatalyst demonstrated high efficiency in the visible light-driven upcycling of plastic waste. Photoluminescence, photoelectrochemical, and time-resolved photoluminescence studies showed that the NiCoS 2 /Cd 0.5 Zn 0.5 S heterojunction effectively enhanced the charge separation and transfer, with a Schottky junction mechanism allowing improved photocatalytic H 2 evolution. The integration of NiCoS 2 with Cd 0.5 Zn 0.5 S enhances the separation and transfer efficiency of the charges, improves visible-light absorption, and reduces reliance on noble metals. This study offers a potent and cost-effective approach to develop stable, exceptionally active photocatalysts for sustainable hydrogen production and plastic waste remediation. NiCoS 2 /Cd 0.5 Zn 0.5 S Schottky heterojunctions enable efficient photocatalytic H 2 production coupled with plastic waste upcycling. The optimized 5%NiCoS 2 /Cd 0.5 Zn 0.5 achieves a high H 2 evolution rate of 55.18 mmol·g −1 ·h −1 using Na 2 S/Na 2 SO 3 as sacrificial agents and demonstrates excellent stability and a cost-effective strategy for solar energy conversion and plastic remediation. Download: Download high-res image (104KB) Download: Download full-size image