Degrading Pesticides with Waste Product: Imidazole-Functionalized Rice Husk Catalyst for Organophosphate Detoxification

Rice husk (RH) is one the largest agricultural waste products worldwide, and rice is one of the crops that use the most pesticides. Among these, organophosphates have been of increasing concern due to their high toxicity. Herein, we report the functionalization of RH with imidazole groups (RHIMZ) to obtain sustainable catalysts from waste for organophosphate degradation. The waste-derived catalyst showed prominent catalytic activity in dephosphorylation reactions with the model substrate diethyl 2,4-dinitrophenyl phosphate (DENDPP), over 10-fold, compared to the spontaneous reaction (lifetime = 1 month). Finally, RHIMZ was also effective in degrading the pesticide Paraoxon (spontaneous lifetime = 1 million years), degrading 60% in 20 days, giving a 10-fold enhancement. Overall, the proposed approach is environmentally friendly for reusing the waste for a noble cause, i.e., degrading toxic pesticides, which is promising for designing sensors and detoxification processes.