TiO2 microrods with stacked 3D nanovoids for photoelectrochemical water splitting

0508513 - ÚACH 2020 RIV DE eng J - Journal Article
Mamoň, Filip - Fajgar, Radek - Jandová, Věra - Kočí, Eva - Jakubec, Ivo - Zhigunov, Alexander - Brovdyová, T. - Bakardjieva, Snejana
TiO2 microrods with stacked 3D nanovoids for photoelectrochemical water splitting.
Pure and Applied Chemistry. Roč. 91, č. 11 (2019), s. 1733-1747. ISSN 0033-4545. E-ISSN 1365-3075.
[International Conference on Solid State Chemistry /13./. Pardubice, 16.09.2018-21.09.2018]
R&D Projects: GA ČR(CZ) GA18-15613S
Institutional support: RVO:61388980 ; RVO:67985858 ; RVO:61389013
Keywords : nanovoids * photoelectrochemistry * SSC-2018 * TiO2 microrods * water splitting
OECD category: Inorganic and nuclear chemistry; Inorganic and nuclear chemistry (UCHP-M); Polymer science (UMCH-V)
Impact factor: 1.919, year: 2019
Method of publishing: Open access with time embargo

This paper reports an original nonstandard green concept to obtain TiO2 microrods with polyhedral densely stacked 3D nanovoids prepared via the heat treatment of a hydrogen titanate. The intermediate hydrogen titanate was synthesized by a solid-liquid-solid (SLS) route from an ammonia-saturated aqueous solution of TiOSO4 at 0 °C. The effect of the postgrowth thermal annealing procedure to remove ice (water) and the proposed mechanism to explain the underlying transitions from the intermediate precursor to nanostructured TiO2 microrods with stacked 3D nanovoids were investigated. The small-angle X-ray scattering (SAXS) analysis indicates that at temperatures above 500 °C, the release of confined ice (water) takes place, which leads to the creation of self-assembled polyhedral nanovoids open to the surface. Their size ranges from 5 to 78 nm in both length and width, with a depth of ~3.88 nm. The first use of these stacked 1D TiO2 microrods as the working electrode in a photoelectrochemical (PEC) cell for water splitting is demonstrated. The estimated value of ζ-potential depends on both annealing temperature and crystallite size. Anatase sample 1D TiO/800 with ζ-potential (−29.1) mV and average crystallite size ~68 nm was observed to be highly stable in aqueous suspension. The SLS method yields low-cost 1D TiO2 materials possessing high photoreactivity with water. The PEC measurements indicate that three-dimensional hollow structures with a controlled geometry via patterned 1D TiO2 surface are promising materials for hydrogen generation from water splitting.
Permanent Link: http://hdl.handle.net/11104/0302580