Novel ZnIn2S4/Co(acac)2: An inorganic-organic hybrid nanocomposite for enhanced removal of imidacloprid from aqueous phase

Abstract

Herein, the synthesis and application of an entirely novel ZnIn2S4/Co(acac)2 (ZIS-Co-2) nanocomposite for degradation of hazardous pesticide imidacloprid (IMD) under visible-light irradiation has been investigated. The ZIS-Co-2 nanocomposite demonstrated an outstanding 97.43 ± 1.84 % removal effectiveness against IMD within 60 min of 23 W LED. This improved catalytic performance was attributable to synergistic effects from ZnIn2S4 doping, which significantly delayed charge recombination and boosted visible-light absorption, promoting efficient photocatalytic degradation. Furthermore, the degradation of IMD was thoroughly verified using chemical oxygen demand (COD), and the total organic carbon (TOC) removal and breakdown mechanism was elucidated using liquid chromatography-mass spectrometry (LC-MS). Notably, the ZIS-Co-2 nanocomposite revealed outstanding recyclability, preserving catalytic activity for up to six cycles and the ability to degrade other emerging contaminants. Furthermore, neither Co(acac)2 nor the combination of ZnIn2S4 with metal complexes has been previously produced or explored for visible light-active photocatalytic applications, highlighting the originality of our study. Overall, the ZIS-Co-2 nanocomposite is a promising and sustainable solution for efficiently removing IMD and other environmental pollutants, with significant practical implications in wastewater treatment and environmental restoration.