Plasma chemical synthesis and modification of MnO₂ as potential photocatalyst

Mixed-phase MnO₂ was obtained by the action of a glow discharge at atmospheric pressure on a solution of KMnO₄ acting as an electrolyte cathode. The process is based on the action of reactive species in the solution possessing reducing properties. Composites based on MnO₂/CuO were obtained by treating the obtained manganese dioxide with underwater plasma. Powder X-ray diffraction, scanning electron microscopy, and molecular nitrogen absorption/desorption were used to characterize the obtained products. It was found that the treatment with underwater plasma leads to the formation of a more developed surface. The obtained materials were tested as a photocatalyst for the decomposition of a model solution of a mixture of dyes (concentration 1.2 mg/L of each). The results showed high photocatalytic activity (100% removal of all dyes within 20-30 min).