Facile synthesis of NiSe2–ZnO nanocomposites for enhanced photocatalysis and wastewater remediation

Abstract

In this study, NiSe₂ nanocubes, ZnO rods, and their composites were prepared by simple chemical methods to investigate their photocatalytic response and antibacterial activity. The optimal concentration of NiSe₂ nanocubes was explored for enhanced photocatalytic performance by varying its percentage in the NiSe₂–ZnO composites. The findings suggested that the optical response of ZnO was significantly improved and shifted towards visible region by incorporating NiSe₂ as a co-catalyst. The photocatalytic properties of NiSe₂, ZnO, and NiSe₂–ZnO composites were assessed under visible light by using methylene blue (MB) as a model pollutant. The results showed that the optimized composite containing 75% NiSe₂ with ZnO exhibited outstanding photocatalytic efficiency of 97%. The degradation of MB dye by NiSe₂, ZnO, and their composites followed the pseudo-first-order reaction kinetics (Langmuir–Hinshelwood model). Furthermore, the prepared NiSe₂–ZnO composite displayed exceptional reusability and stability over a number of cycles, demonstrating its practical applicability. This research presents unique findings, showcasing the comparative antibacterial performance of NiSe₂, ZnO, and NiSe₂–ZnO nanocomposites against Bacillus cereus (B. cereus). Of all the prepared photocatalysts, the 75% NiSe₂–ZnO nanocomposite revealed the best performance, exhibiting an inhibition zone of 28 mm.