Photocatalytic outcomes for methylene blue degradation from CTAB mediated mesoporous ZnS, synthesized with an insoluble precursor in ethanol media

The aim of the present study is to demonstrate how mesoporous nanostructures of Zinc Sulfide (ZnS) will precipitate in an ethanol media in spite of negligible solubility of Sodium Nitrate (Na2S), which is role-played as sulfur precursor. On the following, the role of such synthesizing method on the photocatalytic behavior of ZnS mesoporous nanostructures has been investigated. Characterization of the synthesized samples was carried out through X-ray diffraction patterns (XRD), Furrier Transformation Infrared Spectroscopy (FTIR), Transmission Electron Microscopy (TEM), Diffuse Reflectance Spectroscopy (DRS), Field Emission Scanning Electron Microscopy (FESEM) and N2 adsorption – desorption analysis. Formation of NaNO3 in assistance with negligible solubility of Na2S in ethanol enhances the stability of ZnS nanoparticles. Besides, formation of NaNO3 as well as sonication process can induce mesopores in the ZnS nanoparticles. Changes in the critical micelle concentrations (CMCs) of CTAB had impacts either in the lattice properties or in the textural structure of the mesopores of the synthesized samples. An attempt was made to explain how enhancement of CMCs values made crystallite size decreased and subsequently lattice strain increased. The photocatalytic behavior and the adsorption capacity of the ZnS mesoporous structures were studied through methylene blue degradation from aqueous solution. It was found that adsorption capacity and photocatalytic efficiency of synthesized samples were improved by modification of CMC values of CTAB. Findings were in compatibility with the band gap energy values and water droplet contact angle measurements. This study is finalized with explaining how the synthesized photocatalysts remove contaminations under ultraviolet irradiation.