Plasma electrochemical synthesis of cuprous oxide nanoparticles and their visible-light photocatalytic effect

A plasma electrochemical method is used to synthesize cuprous oxide nanoparticles (Cu2O NPs). In this system, a gaseous discharge plasma is used to replace the usual solid electrode in a conventional electrodeposition, and Cu2+ ions are released from anodic dissolution and take a form of Cu-2(OH)(2+) in the solution. The Cu-2(OH)(2+) moves to the cathode reaction zone and then is reduced to the Cu2O monomer by reductants generated from the plasma-liquid interactions. Consequently, Cu2O NPs are formed in the solution by the combination of Cu2O monomers. The results indicate that the morphology and Cu valence in the nanoparticles are tuned by the added surfactant of glucose or ascorbic acid. Moreover, the Cu2O NPs synthesized with a suitable concentration of ascorbic acid demonstrate strong visible light photocatalytic activity on the methyl orange degradation. (C) 2016 Elsevier Ltd. All rights reserved.