Orange peel-derived Cu₂O/RGO nanocomposite: Mesoporous binary system for degradation of doxycycline in water

In recent times, there is a mammoth challenge for the world and mankind to deal with the frequent use and misuse of antibiotics and its casual discard to the water bodies. The scavenging degradation of antibiotics which are no longer in use from the environment is a growing concern and compulsively needs to be addressed. Herein, we have devised a novel and green protocol for the synthesis of Cu₂O decorated on reduced graphene oxide (Cu₂O/RGO) nanocomposite (NCs) using agro-waste, i.e., orange pomace extract (OPE) as a reducing and stabilizing agent for the degradation of antibiotic. The biogenically synthesized Cu₂O/RGO NCs proved to emerge as an excellent degradation catalyst exhibiting efficiency of 98.68% within 15 min and 86.38% within 30 min for 10 mg/L DC concentration assisted by ultrasound waves and solar light respectively in separate reactions. The complete degradation process followed a pseudo-first-order kinetics with a rate constant of 0.29 min^- 1 and 0.0542 min^- 1 for sonocatalytic and photocatalytic degradation process, respectively. Surface area analysis showed that with the increase in the GO amount, the doxycycline degradation increases. An in-depth mechanistic account of sonocatalytic and photocatalytic process has been discussed followed by a radical scavenging test which validated the major role of the synthesized NCs in the degradation of DC. The extraordinary catalytic indulgence of biogenically synthesized graphene-based nanocatalyst opens newer avenues for future research in green chemistry and catalytic field.

The online version contains supplementary material available at 10.1007/s10668-022-02895-2.