Adsorptive and photocatalytic degradation of imidacloprid pesticide from wastewater via the fabrication of ZIF-CdS/Tpy quantum dots

Abstract

Pesticides used in agriculture are the problematic pollutants in water resources due to their persistence nature in the environment. The main objective of this work is to report a facile one-pot approach to synthesize stable water-dispersible CdS quantum dots (QDs) stabilized by terpyridine-based ligand (CdS/Tpy QDs), which was subsequently loaded onto ZIF-67 surface to prepare a highly efficient photocatalyst. Compared to ZIF-67 and CdS/Tpy QDs, the ZIF-CdS/Tpy nanocomposite exhibited much higher photocatalytic activity in imidacloprid degradation under simulated visible light at neutral pH. Under similar conditions, photocatalytic degradation of imidacloprid in the presence of ZIF-CdS/Tpy was 1.3 and 1.7 times faster than that in the presence of CdS/Tpy QDs and ZIF-67, respectively. The large specific surface area and exceptionally high porosity of ZIF-CdS/Tpy nanocomposite provide rich adsorption sites and the anchoring of CdS/Tpy onto the surface of ZIF-67 could help improve imidacloprid degradation.