Interfacial studies in CNT fibre/TiO${}_2$ photoelectrodes for efficient H${}_2$ production

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 $0.2V$ $vsAg/AgCl$), 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.

References in corpus (3)

• Large area photoelectrodes based on hybrids of CNT fibres and ALD grown TiO2
• Advanced Surface Chemistry Analysis of Carbon Nanotube Fibers by X-ray Photoelectron Spectroscopy
• Porous nanostructured metal oxides synthesized through atomic layer deposition on a carbonaceous template followed by calcination