Enhancing the solar water splitting activity of TiO2 nanotube-array photoanode by surface coating with La-doped SrTiO3.
LUCAS, Thalles Thadeu Assunção; MELO JUNIOR, Mauricio Alves de; FREITAS, André L. M.; SOUZA, Flavio Leandro; GONÇALVES, Renato Vitalino.
LUCAS, Thalles Thadeu Assunção; MELO JUNIOR, Mauricio Alves de; FREITAS, André L. M.; SOUZA, Flavio Leandro; GONÇALVES, Renato Vitalino.
Abstract: Photoelectrochemical water splitting has been considered one of the most promising alternatives for the sub- stitution of fossil fuels with a clean and renewable fuel, such as H2. Two of the most studied photocatalysts for such application are titanium dioxide and strontium titanate due to their favourable photoactivity, robustness and availability; although specific limitations have hindered their large-scale implementations. In this investi- gation, we produced photoanodes comprising heterojunctions of TiO2 nanotubes and lanthanum-doped SrTiO3 for the photoelectrochemical split of water, under simulated solar irradiation. A thin layer of SrTiO3 formed on the surface of TiO2 nanotubes through a hydrothermal route was effective in promoting the electron-hole sep- aration at the interface, leading to a photocurrent density enhancement from 58.9 to 109.4 µA cm??2 (at 1.23 V vs RHE). The charge transfer resistance at the solid/liquid interface was substantially reduced, according to elec- trochemical impedance spectroscopy measurements. Further photoactivity increase was achieved by doping the SrTiO3 overlayer with La3+. This is the first time the application of such La:SrTiO3/TiO2 nanocomposite in sustainable energy production is reported. The doping with 10 mol% of La3+ into the Sr2- sites enhanced the photoelectrochemical response to 144.2 µA cm-2 (1.23 V vs RHE) due to the suppression of deep trapping states related to formed SrO species.
@article={002986966,author = {LUCAS, Thalles Thadeu Assunção; MELO JUNIOR, Mauricio Alves de; FREITAS, André L. M.; SOUZA, Flavio Leandro; GONÇALVES, Renato Vitalino.},title={Enhancing the solar water splitting activity of TiO2 nanotube-array photoanode by surface coating with La-doped SrTiO3},journal={Solar Energy Materials and Solar Cells},note={v. 208, p. 110428-1-110428-9},year={2020}}