Highly Sensitive ppb Level Methanol Sensor by Tuning C:O Ratio of rGO-TiO2 Nanotube Hybrid Structure
| Autor: | Mon-Shu Ho, Partha Bhattacharyya, Debanjan Acharyya, Pei-Fang Chung, Kuo-You Huang, Snehanjan Acharyya |
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| Rok vydání: | 2017 |
| Předmět: |
Nanotube
Materials science Graphene Analytical chemistry Oxide chemistry.chemical_element 02 engineering and technology 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences Oxygen 0104 chemical sciences Computer Science Applications law.invention symbols.namesake chemistry.chemical_compound X-ray photoelectron spectroscopy chemistry law symbols Methanol Electrical and Electronic Engineering 0210 nano-technology Raman spectroscopy Deposition (law) |
| Zdroj: | IEEE Transactions on Nanotechnology. 16:1122-1128 |
| ISSN: | 1941-0085 1536-125X |
| Popis: | In this paper, ppb level methanol sensing by a hybrid gas sensor device based on reduced graphene oxide (rGO) and TiO2 nanotubes is reported. Tuning of carbon to oxygen ratio, in rGO layers, was found to be very effective in modulating the sensor response. The C:O ratio was tuned by varying the voltage (11–31 V) during the electro-deposition of rGO (on top of the TiO2 nanotube matrix) and was confirmed by Raman spectroscopy and X-ray photoelectron spectroscopy. Due to variations in the C:O ratio in rGO, the barrier height of rGO-TiO2 nanotube junctions and etch hole dimension on rGO layer were varied. Judicious optimization of these two pivotal parameters resulted in the sensor device (for rGO deposition voltage of 16 V), capable of detecting ppb level (up to 62 ppb) methanol efficiently. The sensor showed ∼16%, ∼59%, and ∼94% response magnitude for 62 ppb, 1 ppm, and 200 ppm concentrations, respectively. A comprehensive discussion elucidating the role of rGO-TiO2 NTs junctions (with a tunable C:O ratio) has also been presented correlating the experimental findings. |
| Databáze: | OpenAIRE |
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