Controlled synthesis of octahedral Cu2O on TiO2 nanotube arrays by electrochemical deposition

TiO2 nanotube (TNT) arrays loaded with octahedral Cu2O particles were successfully prepared by anodic oxidation followed with cathodic deposition. Annealing the TNT arrays before the cathodic deposition could effectively lower the electric resistance at the bottom of TNTs walls and then favor the deposition of octahedral Cu2O particles into TNT arrays. The effects of the applied reduction potential, the CuSO4 concentration, the pH value, the reaction temperature on the kinetics of cathode deposition and the Cu2O morphology were investigated. It was found that octahedral Cu2O particles were obtained under larger deposition current, while amorphous Cu2O were obtained under smaller current.