4-8 July 2016
Kramer Law building
Africa/Johannesburg timezone
The Proceedings of SAIP2016 published on 24 December 2017
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Effect of Hydrochloric Acid on the Structure, Defect States and Gas Sensing Properties of TiO2 Nanotubes by Hydrothermal Method

Presented by Mrs. Zamaswazi TSHABALALA on 7 Jul 2016 from 10:00 to 10:20
Type: Oral Presentation
Track: Track A - Division for Physics of Condensed Matter and Materials

Abstract

We report on the enhanced gas sensing properties of TiO<sub>2</sub> nanotubes synthesized following a microwave assisted hydrothermal method followed by washing with various concentrations of Hydrochloric acid (HCl) and distilled water (DW). The Scanning electron microscope displayed a change in morphology from nanoparticles to nanotubes after hydrothermal treatment. The nanotubes washed with DW only displayed narrow nanotubes with diameter approximately 13.92 nm. Samples washed with 0.25 and 0.5 M of HCl have diameters approximately 15.08 and 17.09 nm respectively. Introducing 1.0 M HCl more nanotubes were formed with average diameter approximately 22.27 nm. The structural analyses displayed a mixture of anatase and rutile phase with anatase dominating. Moreover, an increase in crystallinity and growth in diameter of the nanotubes is observed at higher HCl concentration. The Photoluminescence (PL) and the Electron paramagnetic resonance (EPR) analysis showed high concentration of oxygen vacancies (V<sub>o</sub>) which have a high contribution on the gas sensing. The gas sensing properties such response, sensitivity and selectivity were carried out towards CH<sub>4</sub>, H<sub>2</sub>, NH<sub>3</sub>, CO and NO<sub>2</sub> gas at different temperatures. The enhanced sensitivity of the TiO<sub>2</sub> nanotubes was attributed to the high surface area provided by the one dimensional nanotubes since they behave as nanochannels for gas diffusion.

Award

Yes

Level

MSc

Supervisor

David Motaung DMotaung@csir.co.za

Paper

Yes

Permission

Yes

Place

Location: Kramer Law building
Address: UCT Middle Campus Cape Town
Room: LT1


Primary authors

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