Facile synthesis of stable Cu and CuO particles for 4-nitrophenol reduction, methylene blue photodegradation and antibacterial activity
Dinesh Patil, J. Manjanna, Santosh Chikkamath, Vijayakumar Uppar, Mallikarjun Chougala
Abstract
For the first time, highly stable Cu metal particles were prepared using cupric acetate precursor and ascorbic acid as a reducing agent in ethylene glycol (EG) at ambient conditions. These submicron particles (SMPs) have shown an excellent catalytic reduction of 4-nitrophenol (NP) to 4-aminophenol (AP) in the presence of NaBH 4 at room temperature in the aqueous medium. During, the successive cycles, the time required for complete reduction was prolonged by a few minutes as a fraction of Cu was converted to Cu 2 O/ CuO over the period of reuse. The spent Cu SMPs were converted to CuO nanoparticles upon heating at around 450 °C for 5 h. The band gap of CuO nanoparticles was determined using Tauc's equation and found to be 3.33 eV. This semiconducting CuO was used as a photocatalyst for the degradation of methylene blue (MB) dye under UV light in basic pH. Active species scavenger study confirms, the OH · are primary species in MB degradation. The possible degraded products of 4-NP reduction and MB degradation were analyzed by mass spectrometry. Furthermore, both Cu and CuO were tested for their antibacterial activity against six different bacterial pathogens. As expected, Cu exhibited good bactericidal activity, when compared to CuO.