Facile synthesis of zero valent sulfur nanoparticles for catalytic detoxification of hexavalent chromium, cytotoxicity against microalgae and ultraviolet protection properties

Industrial effluents that contain various toxic substances have polluted our water and soil and posed major health issues. Thus, their removal or conversion to non-toxic products is highly crucial and desirable. This work emphasizes the synthesis of sulfur nanoparticles through precipitation method using anionic and cationic surfactants for exploring its catalytic efficiency in the photocatalytic reduction of hexavalent chromium Cr (VI). As-synthesized sulfur nanoparticles (SNPs) were physically characterized by UV-Vis absorption, scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and dynamic light scattering (DLS) measurements. The SNPs prepared using both surfactants have narrow size distribution with great homogeneity (50–80 nm). Moreover, excellent efficiency for Cr (VI) to Cr (III) reduction was recorded for SNPs. Besides, cytotoxicity analysis against microalgae Picochlorum sp. was analyzed and the SNPs showed no negative effect on algal growth and chlorophyll a concentration. Finally, the SNPs were found to provide excellent sunlight protection. Our results highlight that SNPs have great potential for the treatment of industrial wastewater with greater reproducibility. Moreover, they are equally effective against harmful sun rays and are suitable in different skin care products.