Facile green synthesis of NiO nanoparticles and investigation of dye degradation and cytotoxicity effects.

Abstract Dispersed nickel oxide nanoparticles (NiO-NPs) have been obtained through a "green" co-precipitation method using nickel nitrate hexahydrate and starch as Ni precursor and stabilizing/capping agent, respectively, while ammonia has been applied in the role of a complex agent throughout this procedure. The structural, photocatalyst, optical, and magnetic qualities of the NiO-NPs have been enquired into by FTIR, UV–Vis, XRD, FESEM, EDX, VSM, and TGA/DTG. Magnetic measurement has confirmed the superparamagnetic behavior of NiO-NPs at ambient temperature after calcination procedures. The band gap of NiO-NPs has been calculated to be about 3.55 eV and thus, this sample is a semiconductor that can be utilized as photocatalysts. According to the obtained results, about 80% of methylene blue (MB) degrades in the presence of NiO-NPs under UV light after 270 min. In vitro cytotoxicity investigations on cells has exhibited a dose-dependent toxicity with non-toxic consequences in concentrations below ∼7 μg/mL. The synthesis outcomes have shown that starch can be an interesting material with the potential of being employed as a stabilizer for preparing small nanoparticles, as well as being a bio-template for nanoparticles growth. Graphical abstract Image Highlights • A facile "green" method was developed to synthesize NiO-NPs in starch solutions. • It was observed that the size of spherical shape NiO-NPs is < 40 nm. • The formed NiO-NPs are characterized by FESEM and XRD. • Cytotoxicity of NiO-NPs showed a toxic effect on cancerous cells. [ABSTRACT FROM AUTHOR]