Synthesis, characterization, electrochemical and catalytic performance of NiO nanostructures and Ag-NiO nanocomposite

Nanocomposites comprising oxide and metal nanoparticles could significantly boost respective functionalities attributing to their synergistic properties. Present work reports synthesis of NiO and its composite; Ag-NiO nanocomposite. The study highlights electrochemical and catalytic performances of synthesized materials. The X-ray diffraction pattern, X-ray photoelectron spectra, magnetic and morphological study is presented with detailed analysis. Transmission electron microscopy images showed Ag nanoparticles distributed within NiO nanostructures. The cyclic voltammetry results showed specific capacitance of 231 F/g for Ag-NiO nanocomposite; higher than bare NiO (90 F/g) at 5 mV/s scan rate in 1 M KOH electrolyte. Moreover, the Ag-NiO nanocomposite exhibited significant catalytic activity towards methylene blue reduction with rate constant 1.1 × 10−2 s−1. The study covers basic analysis of NiO and Ag-NiO nanocomposite extending towards their functional performance

Smart nanocomposites: Harnessing magnetically recoverable MWCNT-CF for efficient organic dyes reduction in water quality monitoring applications

The accelerating use of organic dyes in various industries has led to a surge in water pollution, especially from non-biodegradable dye effluents discharged into water resources. This study addresses the critical issue of catalyzing the reduction of two prevalent dyes, methylene blue (MB) and rhodamine-B (RhB), using a multiwalled carbon nanotube-cobalt ferrite (MWCNT-CF) nanocomposite. The synthesized nanocomposite demonstrates exceptional catalytic activity, stability, and recyclability. Conventional methods for treating dye-containing wastewater often prove expensive. This study explores the efficacy of catalytic reduction, a relatively fast process facilitated by semiconductor nanoparticles. Structural analyses using X-ray diffraction and high-resolution transmission electron microscopy (HRTEM) confirm the formation of the nanocomposite, revealing unsaturated surface bonds and chains conducive to adsorption. The nanocomposite exhibits a remarkable reduction in both dyes, with easy recyclability for multiple cycles. Magnetization studies confirm the ferrimagnetic nature of the nanocomposite, facilitating its efficient separation from the reaction mixture using a magnet. The study delves into the kinetics of the catalytic reduction following pseudo-first-order kinetics. The surface modifications of the nanocomposite, as revealed by TEM, contribute to enhanced adsorption and catalytic efficiency. Notably, the MWCNT-CF nanocomposite demonstrates negligible loss of catalytic activity during recycling, highlighting its potential for cost-effective and sustainable applications in dye reduction across various industries