Photocatalytic Activity of CdS Nanoparticles Obtained by Microbial Synthesis on the Model of Decolorization of Methylene Blue Dye

It has been demonstrated for the first time that biogenic nanoparticles of cadmium sulfide (NPsCdS) obtained using the bacterial strain Bacillus subtilis 168 by an optimized environmentally friendly, nature-like microbial synthesis are able to photocatalytically decolorize methylene blue dye under UV irradiation (365 nm). NPsCdS, characterized as quantum dots, fluoresce in the blue spectral region (400-440 nm), have a spherical shape, a diameter of 5±1 nm and a hydrodynamic diameter of 250--300 nm. The dynamics of methylene blue decolorization was studied depending on the NPsCdS and the dye concentrations, the thickness of the dye solution layer, as well as the power and time of exposure to UV irradiation. The possibility of reusing biogenic NPsCdS for dye decolorization was shown, which characterizes the photostability of the nanoparticles and is relevant for the practical application of biogenic photonanocatalysts. biogenic CdS nanoparticles, Bacillus subtilis 168, photocatalysis, UV irradiation, methylene blue The authors are grateful to the Russian National Collection of Industrial Microorganisms of NRC "Kurchatov Institute" - GOSNIIGENETIKA for providing the bacterial strains and to the Kurchatov Genomic Center-NRC "Kurchatov Institute"- GosNIIGENETIKA for the opportunity to determine the photocatalytic degradation of the dye using biogenic nanoparticles on spectrophotometric equipment. This work was supported by the Russian Foundation for Basic Research in the framework of project no. 19-04-00088.