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Boosting the performance of TiO2 nanotubes with ecofriendly AgIn5Se8 quantum dots for photoelectrochemical hydrogen generation

2021; Elsevier BV; Volume: 506; Linguagem: Inglês

10.1016/j.jpowsour.2021.230165

1873-2755

Danilo A.P. Velásquez, Felipe L. N. Sousa, Thiago A. S. Soares, Anderson J. Caires, Denilson V. Freitas, Marcelo Navarro, Giovanna Machado,

Advanced Photocatalysis Techniques

Photoelectrochemical (PEC) cells composed by ecofriendly quantum dots (QDs) are promising devices for solar-to-hydrogen conversion. In this work, photoanodes of Ti/TiO 2 NTs sensitized by ecofriendly AgIn 5 Se 8 (AISe) QDs are prepared and characterized. Two different electrochemical procedures are used on the preparation of the precursor nanomaterials. TiO 2 NTs are prepared by Ti plate electrochemical anodization and the colloidal aqueous solutions of AISe QDs are prepared by electrosynthesis, using an electrochemical cavity cell. The photoanodes of Ti/TiO 2 NTs are sensitized by the linker-assisted method, i.e. , photoanode immersion in the AISe solution during 2 h, 24 h, and 48 h. The immersion time is an important parameter, where longer periods of immersion provided higher photocurrent density and lower electron-transfer resistance. The photoanodes Ti/TiO 2 NTs/AISe QDs produce a maximum photocurrent after 24 h of sensitization (125 μA cm −2 ), being 2.4 times higher than the Ti/TiO 2 NTs (54 μA cm −2 ). The photoelectrochemical hydrogen production shows up be effective, giving an H 2 total production of 6.47 μmol cm −2 (3.1 times the amount of H 2 produced on Ti/TiO 2 NTs) after 3 h of irradiation (Xe lamp 300 W, AM 1.5 G filter, 100 mW cm −2 ). Therefore, can be expected a potential application of these photoanodes in solar fuel production. • Ecofriendly preparation of Ti/TiO 2 /AgIn 5 Se 8 photoanodes for PEC H 2 production. • Electrochemical preparation of Ti/TiO 2 nanotubes (NTs) and AgIn 5 Se 8 nanocrystals (NCs). • Sensitization of Ti/TiO 2 NTs with AgIn 5 Se 8 QDs by a linker-assisted method. • Immersion time is an important sensitization parameter to reach higher photocurrent. • PEC H 2 production on Ti/TiO 2 NTs/AgIn 5 Se 8 NCs is 3.1 times higher than on Ti/TiO 2 NTs.