Composition-driven morphological evolution of BaTiO3 nanowires for efficient piezocatalytic hydrogen production

Kaili Xue; Yue Jiang; Sajjad S Mofarah; Esmail Doustkhah; Shujie Zhou; Xiaoran Zheng; Suchen Huang; Danyang Wang; Charles C Sorrell; Pramod Koshy

doi:10.1016/j.chemosphere.2023.139337

Composition-driven morphological evolution of BaTiO₃ nanowires for efficient piezocatalytic hydrogen production

Chemosphere. 2023 Oct:338:139337. doi: 10.1016/j.chemosphere.2023.139337. Epub 2023 Jul 11.

Authors

Affiliations

¹ School of Materials Science and Engineering, UNSW Sydney, Sydney, NSW, 2052, Australia.
² School of Materials Science and Engineering, UNSW Sydney, Sydney, NSW, 2052, Australia. Electronic address: yue.jiang2@unsw.edu.au.
³ Koç University Tüpraş Energy Center (KUTEM), 34450, Istanbul, Turkey.
⁴ Particles and Catalysis Research Group, School of Chemical Engineering, UNSW Sydney, Sydney, NSW, 2052, Australia.
⁵ School of Materials Science and Engineering, UNSW Sydney, Sydney, NSW, 2052, Australia. Electronic address: koshy@unsw.edu.au.

PMID: 37442379
DOI: 10.1016/j.chemosphere.2023.139337

Abstract

Hydrogen production from water by piezocatalysis is very attractive owing to its high energy efficiency and novelty. BaTiO₃, a highly piezoelectric material, is particularly suitable for this application due to its high piezoelectric potential, non-toxic nature, and physicochemical stability. Owing to the critical role of morphology on properties, one-dimensional (1D) materials are expected to exhibit superior water-splitting performance and thus there is a need to optimise the processing conditions to develop outstanding piezocatalysts. In the present work, piezoelectric BaTiO₃ nanowires (NWs) were hydrothermally synthesised with precursor Ba:Ti molar ratios of 1:1, 2:1, and 4:1. The morphology, defect chemistry, and hydrogen evolution reaction (HER) efficiency of the as-synthesised BaTiO₃ NWs were systematically investigated. The results showed that the morphological features, aspect ratio, structural stability and defect contents of the 1D morphologies collectively have a significant impact on the HER efficiency. The morphological evolution mechanism of the 1D structures were described in terms of ion exchange and dissolution-growth processes of template-grown BaTiO₃ NWs for different Ba:Ti molar ratios. Notably, the BaTiO₃ NWs synthesised with Ba:Ti molar ratio of 2:1 displayed high crystallinity, good defect concentrations, and good structural integrity under ultrasonication, resulting in an outstanding HER efficiency of 149.24 μmol h^-1g^-1 which is the highest obtained for nanowire morphologies. These results highlight the importance of synthesis conditions for BaTiO₃ NWs for generating excellent piezocatalytic water splitting performance. Additionally, post-ultrasonication tested BaTiO₃ NWs demonstrated unexpected photocatalytic activity, with the BTO-1 sample (1:1 Ba:Ti) exhibiting 56% photodegradation of RhB in 2 h of UV irradiation.

Keywords: BTO nanowires; Defect chemistry; Morphology evolution; Piezocatalysis; Water splitting.

MeSH terms

Barium Compounds
Hydrogen
Ion Exchange
Nanowires*

Substances

barium titanate(IV)
Barium Compounds
Hydrogen