Highly dispersed Zn0.5Cd0.5S nanoparticles anchored on NiCo2O4 nanosheets as the direct Z-scheme heterojunction for enhanced visible light photocatalysis

By virtue of their green and environmentally friendly properties, photocatalysis has become one of the most ideal solutions for antibiotic pollution. Herein, a series of direct Z-scheme Zn 0.5 Cd 0.5 S/NiCo 2 O 4 photocatalysts have been successfully fabricated. The obtained Zn 0.5 Cd 0.5 S/NiCo 2 O 4 photocatalysts displayed outstanding photocatalytic performance for tetracycline hydrochloride (TC-HCl) degradation under the irradiation of a low-energy lamp (white LED lamp, 5 W). Compared to pure Zn 0.5 Cd 0.5 S nanoparticles and NiCo 2 O 4 nanosheets, the Zn 0.5 Cd 0.5 S/NiCo 2 O 4 photocatalysts exhibited significantly enhanced photocatalytic activity. This pleasantly surprised result can be attributed to the formation of Z-scheme heterojunction, which effectively inhibited the recombination of electron–hole pairs and boosted the transfer efficiency of photoinduced electrons. Moreover, anchoring Zn 0.5 Cd 0.5 S nanoparticles on the surface of NiCo 2 O 4 nanosheets can effectively reduce the aggregation of Zn 0.5 Cd 0.5 S nanoparticles and thus increase the active site. Furthermore, free radical trapping experiments confirmed that •O 2− and h + radicals play a major role in the photocatalytic process and verified the rationality of the proposed Z-scheme mechanism. Therefore, our study provides a simple strategy for the construction of direct Z-scheme system with outstanding photocatalytic performance. Graphical abstract