Structural, morphological, optical and UV-light driven enhanced photocatalytic properties of Fe-doped NiO nanoparticles

Abstract

This work comprehensively investigates the effects of iron (Fe) doping on structural, morphological, optical, and photocatalytic properties of nickel oxide (NiO) nanoparticles. The Ni1−xFexO (0.0 ≤ x ≤ 0.1) nanoparticles (NPs) have been prepared by using simple and low cost sol–gel auto-combustion method. The Rietveld refined x-ray diffraction patterns, FT-IR spectra, high-resolution transmission electron microscopy (HRTEM) images and Raman spectroscopy were employed for structural investigations, which confirm the single cubic phase geometry of NiO NPs. The average crystallite size of each sample is found to be decreased from 40 nm to 29 nm for x = 0.0 to x = 0.1. Surface morphology was examined using scanning electron microscopy (SEM), and the presence of Ni, Fe, and O was confirmed using energy dispersive x-ray spectroscopy (EDS). From the UV–Vis absorption spectra, we may deduce that the optical band gap has increased slightly due to Fe doping. Tauc plot analysis reveals that band gap widens as a result of doping. Photocatalytic properties of each sample were evaluated under the ultra-violet light irradiation for the photodegradation of toxic methylene blue (MB) dye in an aqueous medium. The high photocatalytic activity of x = 0.1 sample for MB dye degradation makes it a promising wastewater treatment candidate.