Improving Performance of an Integrated Solar Flow Battery by Cr- and Cu-Doped TiO2 Photoelectrodes

This work reports on the preparation of Cr-doped TiO2 (Cr-TiO2), Cu-doped (Cu-TiO2), and its utilization in the photoanode of a solar redox flow battery (SRFB). A pure TiO2 electrode, Cr-doped TiO2 electrode, and Cu-doped TiO2 electrode coated with different layers are prepared by the sol-gel method. XRD, XPS, and SEM are used to characterize the relevant data of the electrode. All three electrodes show the structure of the anatase phase, but the Cu-TiO2 and Cr-TiO2 electrodes are more crystalline. Using these materials as photoelectrodes to prepare integrated solar flow cells, the semi-cell and full-cell tests show that the doping of Cr and Cu improves the efficiency and charging current of solar cells. The average charging currents of the Cu-TiO2 and Cr-TiO2 electrodes are 384.20 mu A and 450.75 mu A, respectively, compared with the TiO2 electrode; this increment reaches values of 71.23% and 100.97%.

Automated summary

This study focuses on the preparation of Cr-doped TiO2 and Cu-doped TiO2 electrodes and their application in the photoanode of a solar redox flow battery (SRFB). The electrodes, prepared through the sol-gel method, exhibit anatase phase structure, with the Cu-TiO2 and Cr-TiO2 electrodes showing greater crystallinity. Tests on the solar flow cells using these materials as photoelectrodes demonstrate that the doping of Cr and Cu improves the efficiency and charging current, with significant increases observed compared to the pure TiO2 electrode.