Green synthesis of copper nanoparticles using white tea leaf extract: Characterization, adsorption behavior, and antibacterial applications

Abstract

Biosynthesis of metal nanoparticles is a cost-effective and environmentally friendly technology. In the present study, copper nanoparticles (CuNPs) were synthesized using white tea leaf extracts. They were then characterized for their chemical structure and evaluated ability for the methylene blue (MB) degradation in the adsorption system with H2O2. XRD and FTIR analyses revealed that the CuNPs were present as an amorphous phase, with the O-H polyphenol compound bound to the Cu ion. The XPS deconvolution indicated the presence of Cu2+ and Cu+ in the CuNPs. TEM images revealed that the average particle size was less than 10 nm. The CuNPs synthesized using different precursors exhibited effective ability for the MB degradation in the adsorption system. Based on the adsorption theory, the pseudo-second-order model fitted well with the experimental data, and the thermodynamic calculation suggested that the reaction was endothermic, and spontaneous. The CuNPs synthesized using the CuSO4 precursor exhibited higher antibacterial activity compared to those synthesized using Cu(NO3)2. In conclusion, white tea leaf extract is an inexpensive and easily available precursor for the biosynthesis of copper nanoparticles. Further analysis based on an assumed degradation work will be considered in future work.