TiO₂ nanocrystal rods on titanium microwires: growth, vacuum annealing, and photoelectrochemical oxygen evolution

Abstract

Titania nanocrystal rods grown hydrothermally onto titanium microwire are mechanically robust and photoelectrochemically active.

Aerosol-assisted chemical vapour deposition of highly efficient mixed anatase-rutile TiO2 for photoelectrochemical water splitting

“…All samples reported in this article were annealed in air at a relatively low temperature of 550 1C, therefore despite the hydrogen-annealed samples in Table 2 showing higher photocurrent densities, the films outlined here far outperformed those same samples when air annealed instead. The effect of H-annealing, as well as previously studied vacuum annealing, 6,14 will be investigated as part of ongoing work on these films, and other metal oxide films developed in a similar manner.…”

A chemist's guide to photoelectrode development for water splitting – the importance of molecular precursor design

“…Nanostructures such as nanorods/nanotubes are among the most promising due to their high surface area, as well as ordered perpendicular growth relative to the substrate surface allowing for easy transport between the solution bulk and the base of the pores. 151 Ordered growth can also allow for more control over active areas of the crystal, increasing the exposure of specific facets.…”

“…331 TiO 2 , which forms Ti 3+ centres with oxygen vacancies, has been reported to have significantly greater PEC performance after hydrogen or vacuum annealing, and vacuum annealing has also been shown by Marken et al to change the material selectivity from oxygen evolution to chorine evolution in the presence of chloride ions. 13,151…”

“…The Ti 3+ at the surface is both more catalytically active than Ti 4+ , and has a selectivity towards chloride oxidation over hydroxide, as shown in work by Marken et al where TiO 2 in a solution of KCl was inactive to chloride oxidation before vacuum annealing, but active after. 13,151 Finally, the film morphology can be altered due to the impact of dopant precursor presence on the film growth mechanisms (Fig. 14).…”