Formation of Nanodispersed Cuprous Sulfide Powder from Solutions Containing Copper and Sulfur Ions Under Electrolysis Conditions

In recent years, transition metal sulfides have been investigated as electrode materials for supercapacitors. Due to their unique crystal structure, morphology and multiple valence states, copper sulfides have high intrinsic electrical conductivity, which is an important requirement for the fabrication of high-performance supercapacitors. The electrochemical mechanism of nanodispersed copper (II) sulfide formation in sulfuric acid medium was studied by voltammetry method. Under voltammetric conditions at a titanium electrode in the presence of divalent copper ions and tetravalent sulfur, the cathodic processes are the reduction of copper ions to the metallic state and sulfite ions to dispersed elemental sulfur. Freshly-formed nanodispersed copper and colloidal sulfur particles chemically interact in the near-cathode space to form univalent copper sulfide. Under galvanostatic conditions on an electrolyzer with a titanium cathode and copper anode, the influence of current density, concentration of electrolyte components on the current yield of nanodispersed univalent copper sulfide was studied. Under optimal electrolysis conditions, the maximum current yield of copper sulfide (II) is 69.86%. The particle size of the obtained copper (II) sulfide, determined using a Hitachi TM-1000 transmission scanning electron microscope, is in the range of 86 nm.