Electrochemical Synthesis of Chitosan‐co‐polyaniline/WO3⋅nH2O Composite Electrode for Amperometric Detection of NO2 Gas |
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| Authors: | Ashutosh Tiwari Shaoqin Gong |
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| Institution: | 1. Department of Mechanical Engineering, University of Wisconsin‐Milwaukee, 3200 North Cramer Street, Milwaukee, WI 53202, USA;2. Department of Materials, University of Wisconsin‐Milwaukee, 3200 North Cramer Street, Milwaukee, WI 53202, USA |
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| Abstract: | An electrode of hydrated tungsten oxide (WO3?nH2O) embedded chitosan‐co‐polyaniline (CHIT‐co‐PANI) composite was electrochemically prepared on an indium tin oxide (ITO) coated glass surface using mineral acid as a supporting electrolyte. The resulting CHIT‐co‐PANI/WO3?nH2O/ITO electrode was characterized using ultraviolet‐visible spectroscopy (UV‐vis), Fourier transform infrared spectroscopy (FTIR), cyclic voltammetry (CV), and scanning electron microscopy (SEM). The composite electrode exhibited a three‐dimensional nanofibrous structure with the diameter of the nanofibers ranging from 20 to 100 nm. The CHIT‐co‐PANI/WO3?nH2O/ITO electrode allowed for the low potential detection of NO2 gas in acidic medium. The NO2 gas sensing characteristics were studied by measuring change in the current with respect to concentration and time. Using the CHIT‐co‐PANI/WO3?nH2O/ITO electrode, NO2 gas was detected electrochemically without interference at pH 2.0 and 0.25 V vs. Ag/AgCl. The current of the electrochemical cell with the CHIT‐co‐PANI/WO3?nH2O/ITO electrode decreased linearly with an increase in NO2 gas concentration in a range from 100 to 500 ppb with a response time of eight seconds. |
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| Keywords: | Chitosan‐co‐polyaniline/WO3⋅ nH2O Nanofiber composite Sensing electrode NO2 gas sensor Response time |
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