Post-synthetic Ln@modified MIL (Ti) framework in sono-photocatalysis degradation of carbaryl

Carbaryl is one of the most widely applicable pesticide to protect fruits, cereals and vegetables, however it is ascribed as one of human carcinogens by US Environmental Protection Agency. Hence, removal of carbaryl from water down to the permissible level is highly recommended. Therefore, the current study interested in the successful removal of carbaryl by catalytic degradation assisted by sonolysis and photolysis. Metal organic framework-based MIL-125-NH2 was synthesized and post modified with pyridine-2,6-dicarbonyl dichloride to produce PDC-MIL-125-NH2. Secondly, lanthanide (Ln) based Eu and Tb was doped in the PDC-MIL-125-NH2 to obtain [email protected]2. The synthesized materials were characterized and confirmed by 1HNMR, FTIR, SEM, EDX and XRD. The all obtained materials were employed in the sonolysis, photolysis and sono-photolysis degradation of carbaryl. The results declared that the carbaryl degradation was followed the order of MIL-125-NH2 < [email protected]2 < [email protected]@MIL-125-NH2 < [email protected]@MIL-125-NH2 < Eu/[email protected]@MIL-125-NH2. In case of Eu/[email protected]@MIL-125-NH2, the carbaryl degradation amounts (percentage) within 30 min were significantly enlarged from 304 mg/g (40.5%) for sonolysis to 630 mg/g (84%) for photolysis and to 749.7 mg/g (99.9%) for sono-photolysis. Doping of Eu and Tb within [email protected]2 improved the catalytic degradation of carbaryl by factor of 2.1. After doping of Eu/Tb within PDC-MIL-125-NH2, the degradation rate in sono-photolysis was accelerated by factor of 2.6. The catalytic degradation of carbaryl was significantly enhanced by applying of sono-photolysis and by immobilization of Ln within PDC-MIL-125-NH2 catalyst. After 6 repetitive sono-photolysis degradation cycles, the degradation percentage of carbaryl was lowered from 99.9% to 92.4% only.