Abstract
Water splitting by photocatalysis, for example employing seawater or wastewater, has the potential to make a substantial contribution to a future hydrogen economy. New types of 3D metal-wire substrates in woven form or brushes for photoelectrochemical processes are desirable to replace flat semiconductor-coated surfaces. In this report, titanium microwires (100 μm diameter; pre-passivated) are employed to produce high surface area photoanodes with a TiO 2 (rutile) nanocrystal array coating that was grown hydrothermally. A photo-active electrode is obtained with nanocrystal TiO 2 rods of adjustable length from 1.67 μm up to 7.38 μm. Saturation of the photoelectrochemical response occurs at an intermediate length of approx. 3.19 μm with a photocurrent density of approximately 4.4 mA cm −2 at 1.0 V vs. Ag/AgCl (3 M) in aqueous 1 M Na 2SO 4 under 100 mW cm −2 385 nm LED illumination. The effectiveness of vacuum annealing for enhancing TiO 2 photochemical processes is demonstrated. The formation of oxygen in aqueous 1 M Na 2SO 4 electrolyte media (with/without chloride) is assessed using Clark probe measurements. Co-evolution of chlorine was evident in 1 M KCl. This work demonstrates that microwire photoelectrodes for woven form or brush structures are entirely feasible, and that pre-passivated titanium metal can be readily coated with titania nanocrystals via hydrothermal synthesis.
Original language | English |
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Pages (from-to) | 8385-8392 |
Number of pages | 8 |
Journal | New Journal of Chemistry |
Volume | 46 |
Issue number | 18 |
Early online date | 7 Apr 2022 |
DOIs | |
Publication status | Published - 14 May 2022 |
Bibliographical note
Funding Information:We gratefully acknowledge the financial support of the University of Bath and University of Monash, and the provision of a Bath/Monash PhD studentship to T.R.H.L. L.W. thanks the China Scholarship Council (201906870022) for a PhD stipend.
ASJC Scopus subject areas
- Catalysis
- General Chemistry
- Materials Chemistry