Sonochemical synthesis of amphoteric Cu0-Nanoparticles using Hibiscus rosa-sinensis extract and their applications for degradation of 5-fluorouracil and lovastatin drugs.

Recent studies reported the detection of numerous emerging and active pharmaceutical constituents in the ground and surface water. To address these issues, the present study reported the ultrasound-assisted synthesis of zero-valent copper (Cu0) nanoparticles using Hibiscus rosa-sinensis extract as reducing and stabilizing agent. The catalyst was characterized using XRD, SEM, EDX, PSA, BET, etc., and the results revealed that sonochemical synthesis technique influenced the crystallinity with controlled growth of Cu0. While the hard ligand hydroxyl group (-OH) reduces the Cu2+ to Cu0 and soft ligand carbonyl group (CO) present in the oxidized polyphenols helps in capping and stabilizing the Cu0-nanoparticles. During the ultrasound application, continuous release of Cu+ from Cu0 promoted the degradation by producing OH and O2•- radicals. Approx. 91.3 % and 93.2 % degradation efficiencies were achieved for 5-fluorouracil and lovastatin. The results showed that Cu0 nanoparticles were amphoteric in nature and the synergy calculation revealed that ultrasound has a direct influence on degradation of drugs which are difficult to degrade/mineralize using conventional techniques. Based on the results, a possible degradation mechanism of drug molecules in the presence of oxidants, zero-valent copper and ultrasound has been proposed.