Shape-controlled synthesis of cuprous oxide nanocrystals via the electrochemical route with H2O-polyol mix-solvent and their behaviors of adsorption.

With H2O-polyols (glycerol, ethylene glycol and polyethylene glycol 400) mix-solvent as media in the NaCl-NaOH-NaNO3 electrolytic system, we developed a simple and efficient electrochemical route for the synthesis of Cu2O nanocrystals with different morphology. The SEM results indicated that electrolytic media and current density had a great influence on the shape of Cu2O crystals. The mono-disperse and uniform sphere Cu2O nanoparticles could be readily obtained in H2O-glycerol (or H2O-ethylene glycol) mix-solvent (1:1 volume ratio) and current density 5 mA/cm2. The sphere Cu2O nanoparticles exhibit excellent adsorption ability for organic dyes (methyl orange, fuchsin acid and methyl blue), which is obviously superior to that of the irregular shape Cu2O crystals prepared in H2O-PEG400 (polyethylene glycol 400) mix-solvent. The present work further confirmed that the adsorption ability of Cu2O crystals was related to their size and shape.