Green synthesis and catalytic activity of copper nanoparticles supported on TiO2 as a highly active and recyclable catalyst for the reduction of nitro-compounds and degradation of organic dyes

In this research, Cu/TiO2 nanocomposite has been successfully synthesized through Chimonanthus praecox flower extract and applied for the reduction of various pollutants such as 2,4-dinitrophenylhydrazine (2,4-DNPH), 4-nitrophenol (4-NP), Congo red (CR), methylene blue (MB), and Nigrosin (NS) at ambient temperature in eco-friendly media. The raw extract was identified by FT-IR and UV–visible techniques. The UV–Vis spectra confirmed the formation of Cu NPs. The functional groups of the methanolic extract involved in the synthesis and stabilization of Cu NPs were investigated by FT-IR. Besides, the Cu/TiO2 nanocomposite with the size of 55 nm was characterized using XRD, SEM, EDS, elemental mapping, TEM, UV–Vis, and FT-IR techniques. The ensuing Cu/TiO2 nanocomposite demonstrated superior catalytic prowess (100% conversion within a short time for the aforementioned pollutants. The remarkable advantages of this green protocol exhibit operational simplicity, easy workup procedure, inexpensive, evading of toxic solvents, and also avoidance of high temperature and pressure. Furthermore, Cu/TiO2 nanocomposite was recyclable for 5 cycles and showed high recyclability, excellent chemical stability, and a promising efficiency in the fast reduction of organic pollutants in aqueous media.