Mixed solvent based surface modification of CuS nanostructures for an excellent photocatalytic application

Abstract

A variety of high-quality, shape and size consistent nanostructures of copper sulfide (CuS) in the form of hierarchical architectures composed of intersecting nano-sheets have been fabricated via mixed solvent route. Copper chloride and thiourea have been utilized as precursors for copper and sulfur sources for each experimentation in the presence of a variety of mixed solvents to obtain various morphologies of CuS. The prepared products have been characterized by X-ray powder diffraction (XRD) and all of the synthesized products have been investigated to be the phase pure single crystalline. Scanning Electron Microscopy (SEM) revealed the well-ordered and isolated particles. The Energy Dispersive Spectroscopy (EDS) spectrum further proved that the obtained products in all of the synthetic processes don’t contain any kind of impurity. Ultraviolet– visible–near infrared (UV–vis–NIR) transmittance spectrophotometer has been utilized to ascertain the optical properties of the as prepared nanostructures. An extended U.V absorption in near-IR region, indicate the covellite phase of CuS. Most importantly, the synthesized nanostructures demonstrated an excellent photo-catalyst response in degrading highly concentrated rhodamine B (RhB) dye aqueous solutions under visible light irradiation along with an excellent reusability, suggesting a promising application in wastewater purification. The excellent photo-catalytic activity has been attributed to surface hierarchical structure with good absorbing and adsorbing properties, high visible light utilization and low electron hole recombination rate.