Comparative Analysis and Applications of Green Synthesized Cobalt Oxide (Co3O4) Nanoparticles: A Systematic Review

The green synthesis method is an eco-friendly and sustainable approach to producing nanoparticles, contributing to lowering environmental impact and enhancing their compatibility for biological applications. Cobalt oxide (Co3O4) nanoparticles have recently gained significant attention due to their unique properties and diverse applications in various fields. This review presents a comprehensive comparative analysis of different green synthesis routes for Co3O4 nanoparticles, including plant extracts, microorganisms, and other natural sources. Various physicochemical characterization methods like X-ray diffraction, scanning electron microscopy, transmission electron microscopy, Fourier-transform infrared spectroscopy, and UV-vis spectroscopy are employed to evaluate the synthesized nanoparticles' structural, morphological, and optical properties. Also, this review examines the applications of green-manufactured Co3O4 nanoparticles in catalysis, sensors, energy storage devices, eco-friendly remediation, and biomedical fields. The comparative analysis highlights the advantages and limitations of different green synthesis methods regarding nanoparticle size, morphology, stability, and functional properties. Insights from this comparative analysis provide valuable guidance for optimizing green synthesis approaches and expanding the applications of Co3O4 nanoparticles in various domains, paving the way for sustainable and eco-friendly nanomaterial synthesis and utilization.