Enhancing the solar water splitting activity of TiO2 nanotube-array photoanode by surface coating with La-doped SrTiO3

Autor(es)

Lucas, Thalles T. A. ^[1] ; Melo, Mauricio A. ^[1] ; Freitas, Andre L. M. ^[2] ; Souza, Flavio L. ^[2] ; Goncalves, V, Renato

Afiliação do(s) autor(es)

^[1] V, Univ Sao Paulo, Sao Carlos Inst Phys, POB 369, BR-13560970 Sao Carlos, SP - Brazil

^[2] Fed Univ ABC, BR-09210580 Santo Andre, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: SOLAR ENERGY MATERIALS AND SOLAR CELLS; v. 208, MAY 2020.
• Citações Web of Science: 0

Resumo

Photoelectrochemical water splitting has been considered one of the most promising alternatives for the substitution of fossil fuels with a clean and renewable fuel, such as H-2. 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 investigation, 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 separation at the interface, leading to a photocurrent density enhancement from 58.9 to 109.4 mu A cm(-2) (at 1.23 V vs RHE). The charge transfer resistance at the solid/liquid interface was substantially reduced, according to electrochemical 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 mu A cm(-2) (1.23 V vs RHE) due to the suppression of deep trapping states related to formed SrO species. (AU)

• Processo FAPESP: 17/18716-3 - Fotossíntese artificial: desenvolvimento de sistemas Tandem para a produção de hidrogênio combustível a partir da água e luz solar
• Beneficiário: Renato Vitalino Gonçalves
• Modalidade de apoio: Auxílio à Pesquisa - Jovens Pesquisadores