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arXiv · 2012.01109

Interfacial studies in CNT fibre/TiO$_{2}$ photoelectrodes for efficient H$_{2}$ production

Alicia Moya·Mariam Barawi·Belén Alemán·Patrick Zeller·Matteo Amati·Alfonso Monreal-Bernal·Luca Gregoratti·Víctor A. de la Peña O'Shea·Juan J. Vilatela
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Abstract

An attractive class of materials for photo(electro)chemical reactions are hybrids based on semiconducting metal oxides and nanocarbons (e.g. carbon nanotubes (CNT), graphene), where the nanocarbon acts as a highly-stable conductive scaffold onto which the nanostructured inorganic phase can be immobilised; an architecture that maximises surface area and minimises charge transport/transfer resistance. TiO$_{2}$/CNT photoanodes produced by atomic layer deposition on CNT fabrics are shown to be efficient for H$_{2}$ production ($0.07 \mu mol/min$ $H_{2}$ at $0.2V$ $vs Ag/AgCl$), nearly doubling the performance of TiO$_{2}$ deposited on planar substrates, with $100 \%$ Faradaic efficiency. The results are rationalised based on electrochemical impedance spectroscopy measurements showing a large reduction in photoelectron transport resistance compared to control samples and a higher surface area. The low TiO$_{2}$/CNT interfacial charge transfer resistance ($10 \Omega$) is consistent with the presence of an interfacial Ti-O-C bond and corresponding electronic hybridisation determined by spatially-resolved Scanning Photoelectron Microscopy (SPEM) using synchrotron radiation.

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Alicia Moya, Mariam Barawi, Belén Alemán, Patrick Zeller, Matteo Amati, Alfonso Monreal-Bernal, Luca Gregoratti, Víctor A. de la Peña O'Shea, Juan J. Vilatela. 2020-12-02. Interfacial studies in CNT fibre/TiO$_{2}$ photoelectrodes for efficient H$_{2}$ production. https://doi.org/10.1016/j.apcatb.2020.118613

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