Design of simple and efficient metal nanoparticles templated on ZnO-chitosan coated textile cotton towards the catalytic reduction of organic pollutants

In this study simple, facile and highly active silver coated ZnO-chitosan (Ag/ZnO-CH) textile cotton supported nanocomposites were developed. The nanocomposites were characterized by UV-visible spectroscopy, scanning electron microscopy (SEM), energy dispersive X-rays spectroscopy (EDX), fourier transform infrared spectroscopy (FTIR) and X-rays diffraction (XRD). The prepared nanocomposite fibers were used for the selective removal of seven model pollutants, including para-nitrophenol (p-NP), meta-nitrophenol (m-NP), ortho-nitrophenol (o-NP), 2,4,6-trinitrophenol (TNP), and dyes of methyl orange (MO), congo red (CR), and methyl red (MR). The apparent rate constant (K _app ) of pseudo first order kinetic for p-NP was 2.813 × 10 ⁻³ s ⁻¹ and 1.663 × 10 ⁻³ s ⁻¹ for MO dye. Among the different nitroarenes, the reaction rate matched the ordered of p-NP >TNP > m-NP > o-NP, while for the dyes it was MO > CR > MR. Ag/ZnO-CH nanocomposites were recycled multiple times without any significant loss of its catalytic activity. The higher stability of the Ag/ZnO-CH nanofibers also allows the catalyst to be separated easily by just pulling the catalyst from the reaction mixture and reused. The clean and facile, simple synthesis procedure, outstanding properties and low-cost supports allow these catalysts to be used in the reduction of the organic pollutants individually as well as collectively in the mixture of dyes in wastewater at room temperature.