Evaluation of Physicochemical, Optical, Morphological, and Photocatalytic Properties of Metal Oxide Nanostructures Derived From Metal Organic Hybrids

p-Nitrophenol (PNP) is a toxic and persistent organic pollutant that poses serious risks to the environment and human health due to its carcinogenic and mutagenic properties. Therefore, it is essential to alleviate these toxic substances from aqueous environments to preserve freshwater resources and protect our well-being. Photocatalysis is considered a promising route for dye and pollutant degradation, where a photocatalyst generates electron-hole pairs by absorbing light (UV or visible) to drive the essential degradation process. Traditionally, various metal oxides have been utilized as photocatalysts for the degradation of organic pollutants and dyes. In this present study, several metal oxide nanoparticles (NPs), such as ZnO, CuO, NiO, CoO, and FeO, were synthesized from metal-organic frameworks by a simple cost-effective coprecipitation method followed by calcination to evaluate their photocatalytic activity toward PNP degradation. The crystallinity, elemental composition, and surface morphology of the prepared samples were investigated using powder x-ray diffraction (XRD) analysis, energy-dispersive x-ray analysis (EDX), and field-emission scanning electron microscopy (FESEM) analysis. The band gap and optical properties were studied using ultraviolet-visible (UV–vis) spectral analysis. Among the metal oxides studied, CoO with a particle size of 9.97 nm and an optimal band gap of 2.07 eV revealed the highest photocatalytic degradation efficiency under optimized conditions. These findings provide insight into the potential application of CoO as an effective photocatalyst for the treatment of PNP-contaminated wastewater. © 2026 Wiley-VCH GmbH.