RGO and TiO2 Nanotube Matrix based Binary Hybrid Device for Reliable Detection of Methyl Acetate Vapor

This paper demonstrates the development of highly sensitive methyl acetate sensor based on reduced graphene oxide (RGO) decorated TiO2 nanotube (NT) matrix. Methyl acetate is a colorless, volatile liquid, used as a solvent... [ view full abstract ]

This paper demonstrates the development of highly sensitive methyl acetate sensor based on reduced graphene oxide (RGO) decorated TiO2 nanotube (NT) matrix. Methyl acetate is a colorless, volatile liquid, used as a solvent during the preparation of wine, resins, dyes and pharmaceutical products. Inhalation of such acetate vapors (even mild amount) can cause irritation in eye and skin, dyspnea, palpitations, headache, ataxia, asthenia, etc. Therefore, efficient detection of acetate contamination is important to the beverage and pharmaceutical industry for securing the human safety. However, commercial unavailability of such sensors warrants the development of a potential methyl acetate sensor. In this study, RGO decoration on TiO2 NT matrix was performed by two-step electrochemical process. Acetate vapor sensing performance of the device was tested towards methyl acetate, ethyl acetate and n-butyl acetate vapors (in the concentration range of 1-400 ppm). The High mobility RGO clusters on TiO2 NTs facilitates the enhance sensitivity towards methyl acetate at 210°C in a high dynamic concentration range. The response magnitude, response time and recovery time was found to be 85.87%, 30 sec and 90 sec respectively, towards 400 ppm methyl acetate. Fig. 1(f) represents the response magnitude variation with the exposure of three vapors for different concentrations at 210°C. It is worth mentioning that, at the same concentration, response magnitude towards methyl acetate is significantly higher than that of the others. The high sensitivity of methyl acetate at lower temperature attributed to the smaller molecular size and lower bond dissociation energy than that of its counter parts. A transient response characteristic towards exposure of methyl acetate is plotted in Fig. 1(h), which substantiates the RGO decorated TiO2 NTs matrix as an efficient methyl acetate sensor. Response and recovery time with the exposure of methyl acetate are depicted in Fig. 1(i) and found to be very promising. Such highly sensitive phenomenon possibly attributed to the high surface to volume ratio of TiO2 NTs matrix as well as high mobility carriers in RGO. According to the literature review, it is imperative to mention that this is the first report on solid state device based methyl acetate sensor.