Electrochemical Investigation of Metal Oxide Conducting Electrodes for Direct Detection of Sulfide |
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Authors: | Md Abdul Aziz Manzar Sohail Munetaka Oyama Wael Mahfoz |
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Institution: | 1. Center of Research Excellence in Nanotechnology, King Fahd University of Petroleum and Minerals, Dhahran 31261, Saudi Arabia tel: +966‐13‐860‐3744, fax: +966‐13‐860‐7264;2. Department of Material Chemistry, Graduate School of Engineering, Kyoto University, Nishikyo‐ku, Kyoto 615‐8520, Japan |
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Abstract: | This study examined the performance of four conducting metal oxide electrodes for the direct electrochemical analysis of sulfide; the electrode materials studied were indium tin oxide (ITO), fluorine doped tin oxide (FTO), aluminum doped zinc oxide (AZO) and gallium doped zinc oxide (GZO). Cyclic voltammetry (CV) results obtained using the ITO, AZO, GZO and FTO electrodes showed direct electrooxidation peak potential of sulfide at 381, 507, 400, and 850 mV vs. Ag/AgCl, respectively; however, the less positive oxidation potential and high catalytic current response of the ITO electrode made it the electrode of choice for the direct oxidation of sulfide. The effects of different electrolytes and buffer solutions on the CV responses were also evaluated. A linear concentration range up to 350 µM and a detection limit of 8.0 µM were achieved. CV response was highly reproducible, remaining unaffected even after 50 measurements. The sensor was found to have good selectivity, with no interference from sulfite, sulfate or chloride ions. The present findings demonstrate that the bare ITO electrode can be used as the basis of an inexpensive, sensitive, selective and robust sulfide sensor. |
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Keywords: | Sulfide Indium tin oxide Electrochemical sensor Stability Selectivity |
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