Photocatalytic activity and anticancer properties of green synthesized ZnO-MgO-MnO nanocomposite via Ocimum basilicum L. seed extract.

Green synthesis using plant extracts such as Ocimum basilicum L. (OBL) seed has attracted attention due to its sustainable and environmentally friendly nature. In this study, ZnO-MgO-MnO nanocomposites were synthesized using OBL seed extract at two different calcination temperatures of 500 °C and 600 °C, and evaluated in terms of photocatalytic application and cytotoxicity. Phytochemicals in OBL seeds act as reducing and masking agents in the production route, which leads to the formation of nanomaterials with unique properties. Characterization techniques, including XRD, FE-SEM, and DRS were used to analyze the structural, morphological, and optical features of the nanocomposite. XRD results confirmed increasing crystal size from ~ 32 nm (500 °C) to ~ 84 nm (600 °C). Also, FE-SEM images showed formation of irregularly shaped nanocomposites and the EDX spectra of the samples confirmed the presence of zinc, magnesium, manganese, and oxygen elements. The photocatalytic behavior of the nanocomposite cacined at 500 °C was investigated for different organic pollutants. Removal percentages of 97% for Eriochrome Black T dye (pH = 10 for 90 min), 99% for methylene blue dye (pH = 10 for 60 min), 89% for methyl orange dye (pH = 10 for 105 min), and 86.9% for Rhodamine B dye (pH = 3 for 90 min) were obtained. Moreover, the cytotoxicity of the synthesized nanocomposite at 500 °C was evaluated on the 4T1 cell line to investgate its effect on biological systems, and the IC value was obtained around 323 µg/mL.