Preparation of 3D TiO2 nanotube arrays photoelectrode on Ti mesh for photoelectric conversion and photoelectrocatalytic removal of pollutant

The 3D TiO2 nanotube arrays (TiO2 NTs) were prepared by the anodization of Ti meshes via adjusting the anodization voltage. The anodization voltage between 15 and 60 V could form the uniform tubular structures revolving around Ti wires, and the diameter and length increased with the increasement of voltages. The results indicated that the anatase TiO2 NTs (30) prepared with the andization voltage of 30 V showed excellent solar photocurrent, photovoltage, interface impedance and photoelectrocatalytic (PEC) efficiencies for the removal of dye molecules and Cr(VI) heavy metal ions. The TiO2 NTs (30) sample with the average diameter of 70 nm and thickness of 4.56 μm showed photocurrent density of 1.63 mA/cm2, photovoltage of −0.36 V/cm2 and removal efficiencies of 71.31%, 51.39%, 98.07% and 48.26% for the PEC removal of methyl orange (MO), Rhodamine B (RhB), methyl blue (MB) and Cr(VI), respectively. The excellent photoelectrochemical propery of TiO2 NTs (30) could be attributed to the effective pollutant adsorption and carrier transportation. This flexible photoelectrode would cause intense attention in the applications of solar cells, pollutant degradation, photolysis of water, and gas sensor.