ELECTROCHEMICAL REDUCTION DOPING OF TiO2 NANOTUBES TO INCREASE THE EFFICIENCY OF PHOTOELECTROCHEMICAL WATER SPLITTING

Abstract

TiO2 films being a 1D nanotube structure were obtained by electrochemical anodic oxidation of titanium foil. Electrochemical reduction activation of electrodes based on TiO2 nanotubes was carried out using the method of cyclic voltammetry (CV). The activated electrodes showed significantly higher current density and quantum efficiency of the photoelectrochemical water splitting compared to native TiO2 nanotubes. Electrochemical treatment of electrodes by the CV method leads to an increase in the photocurrent density from 4 to 14 times, depending on both the wavelength used and the applied potential. The analysis of electrochemical impedance spectra showed that the increase in the photoelectrochemical process performance is due to an increase in the charge transfer rate at the semiconductor/electrolyte interface, as well as improved electronic conductivity of the oxide layer, which contributes to better charge carrier separation and a decrease in their recombination rate.