Fabrication of cobalt oxide nanosheets using Withania somnifera root extract for degradation of organic pollutants

In today’s scenario, material science emerges as pivotal players, as it is an emerging and fast-growing interdisciplinary field. Nanomaterials are increasingly popular among researchers due to their unique physicochemical properties and multifaceted applications. Recently, researchers are exploring more sustainable approaches for the synthesis of nanomaterials due to its numerous advantages. In this context, present investigation reports an approach for the synthesis of cobalt oxide nanosheets (Co 3 O 4 NSs). This approach leverages environmentally friendly and sustainable methods, minimizing the use of hazardous chemicals and reducing energy consumption. Hence it involved Withania somnifera (ashwagandha) root extract as a greener reductant as well as stabilizing agent. The synthesized Co 3 O 4 NSs were thoroughly analyzed using various techniques, including ultraviolet-visible (UV-vis) spectroscopy, fourier-transform infrared spectroscopy (FTIR), powder x-ray diffraction (PXRD), and field emission scanning electron microscopy (FE-SEM). A sharp absorption peak at 252 nm with a tail towards higher wavelength reveal the formation of Co 3 O 4 NSs. The diffraction pattern reveals a face centered cubic structure of Co 3 O 4 NSs. Morphological studies confirmed the substantial surface area of the Co 3 O 4 NSs which enable us to perform the catalytic degradation of azo dye, i.e., methyl orange. It provides that 10 mg of Co 3 O 4 NSs is sufficient to degrade a 10 ppm aqueous methyl orange solution by 75.82% in the dark and by 96.12% under sunlight exposure. Thus, this study offers an excellent pathway for the synthesis of Co 3 O 4 NSs and demonstrates their potential as a promising material for future catalytic applications. • An approach for synthesis of cobalt oxide nanosheets is reported. • Introduction of Withania somnifera (ashwagandha) root extract as a greener reductant as well as stabilizing agent. • Substantial surface area of the Co 3 O 4 make them promising candidate for catalysis • Azo dye degradation was done using cobalt oxide nanosheets • Excellent photocatalytic activity was noticed.