Photodegradation of methyl orange over Cu, Co AND Fe doped NiO under visible light

This study focuses on the photocatalytic degradation of methyl orange (MO) using Cu, Co, and Fe doped nickel oxide (NiO) catalysts synthesized via the precipitation method. Characterization was carried out using Fouriertransform infrared spectroscopy (FTIR) and ultraviolet-visible (UV-Vis) spectroscopy, while further structural analysis is recommended through Raman and X-ray diffraction (XRD) techniques. FTIR results confirmed the formation of Ni-O bonds and identified secondary peaks corresponding to C-O and nitrate residues. The absence of a broad absorption band around 3200–3600 cm⁻¹ indicates complete oxide formation with minimal hydroxyl content. However, UV-Vis analysis showed an increase in absorbance under light exposure, suggesting poor photocatalytic performance. This may be attributed to low dopant concentration, neutral pH conditions, and insufficient light intensity. Although the catalysts were successfully synthesized, the overall photocatalytic degradation efficiency remained low. Future improvements should focus on optimizing dopant levels, modifying solution conditions, and confirming doping success via Raman and XRD analysis.