Fabrication of electrochemically nonporous NiO–ZnO/TiO2 nanotubes/Ti plates for photocatalytic disinfection of microbiological pollutants

Abstract

Nonporous NiO–ZnO/TiO2 nanotubes/Ti photocatalyst plates were fabricated via facile electrochemical method. The structural and morphological properties of the modified plates were investigated by scanning electron microscopy and X-ray diffraction, while their photoelectrochemical (PEC) characterizations were evaluated by transient photocurrent responses and electrochemical impedance spectroscopy. Antimicrobial activities of the fabricated plates against Escherichia coli bacteria and Candida albicans fungi were studied under UV light irradiation. The results indicated that the photocatalytic and PEC activities of the NiO–ZnO/TiO2 nanotubes/Ti plates are much higher than those of TiO2 nanotubes/Ti, ZnO/TiO2 nanotubes/Ti and NiO/TiO2 nanotubes/Ti. The synergetic effect among NiO, ZnO and TiO2 nanotubes motivated a fast charge separation as well as a slow electron/hole recombination, thus increasing the photocatalytic performance of the nonporous NiO–ZnO/TiO2 nanotubes/Ti photocatalyst plate.