Heterogeneous Deposition of Cu2O Nanoparticles on TiO2 Nanotube Array Films in Organic Solvent

A novel method for decoration of anodic TiO2 nanotube array films (NAFs) with Cu2O nanoparticles has been reported. The method is based on the reduction of Cu(II) in a mixture of ethylene glycol and N,N-dimethylformamide at 120 degrees C for 16 h, where the resulting Cu2O can heterogeneously nucleate and grow on TiO2 NAFs. The nanosized Cu2O is found to be well dispersed on the wall of TiO2 nanotubes without blocking the nanotube, a commonly observed phenomenon in the case of deposition of Cu2O via electrochemical method. The amount of Cu2O deposited on the TiO2 NAFs can be varied by adjusting the concentration of Cu(II) in the organic solution. UV-vis spectra measurement indicates that the decoration of TiO2 NAFs with Cu2O nanoparticles greatly improves their ability to respond to visible light. By examining the photocurrent and photodegradation of methyl orange under simulated sunlight, it is found that these Cu2O-decorated TiO2 NAFs show much more photoactive in comparison with the as-prepared TiO2 NAFs.