Fabrication of Z-scheme Cd0.85Zn0.15S/Co9S8 dual-functional photocatalyst for effective hydrogen evolution and organic pollutant degradation

Abstract A Z-scheme Cd 0.85 Zn 0.15 S/Co 9 S 8 (CZS-CS) photocatalyst was reasonably fabricated by a simple solvothermal method for the effective visible-light-driven H 2 evolution and organic pollutants degradation. The precise construction of the CZS-CS composites provided an efficient heterogeneous contact interface and abundant reaction sites for the proposed photocatalytic reaction. The homogeneous Co 9 S 8 nanocrystals were uniformly wrapped on the surface of Cd 0.85 Zn 0.15 S nanorods, forming an intimate-contact interface, markedly contributed to the light collection and effectively inhibited the charge-carrier recombination. The optimized CZS-CS-15 composites exhibited a special H 2 production rate reaching 19.15 mmol·h −1 ·g −1 , roughly 1915 and 4.5 times of pure Co 9 S 8 and Cd 0.85 Zn 0.15 S samples and 85% of tetracycline (TC) molecule within 15 min was degraded. Furthermore, trapping experiments confirmed that h + was the main active species for TC photodegradation. Moreover, the obtained photocatalysts manifested stability without apparent activity declines during the proposed reactions. Finally, the Z-scheme photocatalytic mechanism was verified to illustrate the characteristics of efficient charge transfer and high redox ability. This study provided a rational and learnable strategy for designing dual-functional Z-scheme heterojunction photocatalysts.