Sustainable synthesis of HKUST-1 and its composite by biocompatible ionic liquid for enhancing visible-light photocatalytic performance

Cyhalothrin is lethally toxic to aquatic organisms and has caused adverse effects in the hydrosphere . It is urgent to develop efficient and sustainable material for its removal. High-quality HKUST-1 was rapidly synthesized by cholinium ionic liquids (ILs) in water at room temperature. Yields of HKUST-1 showed obviously positive correlation with Hammett values of ILs. When applying CuCl 2 as a copper salt, the yield of products was reached up to 95.5%, which was much higher than that of reported research. The reaction could be readily scalable with high space-time yield (242512 kg m −3 d −1 ). Additionally, ZrO 2 @HKUST-1 composite was successfully synthesized through a sol-gel method without complicated heat treatment. The whole process eliminates the use of environmentally unfriendly solvents/amines and enables the production of material at a reasonable cost. The obtained HKUST-1 and ZrO 2 @HKUST-1 possessed large pore volume (0.88–0.95 cm 3  g −1 ) and high surface area (1152–1484 m 2  g −1 ). The composite material was used for the adsorption/degradation of cyhalothrin and showed superior photocatalytic activity under moderate visible light, as compared to pure ZrO 2 , HKUST-1 and commercial TiO 2 samples. ZrO 2 @HKUST-1 displayed the high cyhalothrin adsorption capacity of 333 mg g −1 through π−π stacking, which facilitated more target molecules to contact the composite in a short time. ZrO 2 incorporating with HKUST-1 protected ZrO 2 nanoparticles from rapid agglomeration, thus narrowed the band gap of the composite. Moreover, the formation of a junction between HKUST-1 and ZrO 2 effectively reduced the recombination of photoinduced carriers in composite. Therefore, the novel ZrO 2 @HKUST-1 composite can be used as a sustainable efficient heterogeneous photocatalyst for the removal of organic pollutant.