Conformal growth of ZnO on TiO2 nanowire array for enhanced photocatalytic activity

Abstract

Quasi-aligned core–shell TiO2/ZnO nanowires were fabricated by a conformal growth of ZnO along TiO2 nanowires through pulsed laser deposition. The TiO2 nanowire array was fabricated simply by direct oxidation of metallic Ti substrates in hydrogen peroxide solutions containing trace melamine and nitric acid. The X-ray diffraction pattern shows that, the ZnO layer was oriented grown to exhibit an abnormal strong X-ray peak corresponding to (0 0 2). The UV–vis diffuse reflectance spectra reveal that the bandgap of TiO2 nanowire array and that after the ZnO deposition for 30 min was 3.1 eV and 2.7 eV, respectively. The pulsed laser deposition of ZnO on the TiO2 nanowire array is effective to improve both the photoelectrochemical response and the efficiency to assist photodegradation of rhodamine B in water.