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Abstract: An amperometric sensor that measured ascorbic acid by the oxidation of the ascorbic acid on a Ni–Pt electrode was fabricated. The Ni component of the Ni–Pt alloy played a crucial role as a modifier that developed an erinaceous surface, which enlarged the sensing area and increased the sensitivity of the electrode. The Pt82Ni18 electrode exhibited the best sensitivity of 333μAcm−2 mM−1 for ascorbic acid sensing. This electrode was further tested for reproducibility of the sensitivity, endurance, and interference; it exhibited excellent performance compared with electrodes reported in the literature. [Copyright &y& Elsevier]

Abstract: In this paper, binary Pt–Ru/Nafion working electrodes for amperometric sensing of hydrogen were characterized and evaluated. Pt was alloyed with Ru on Nafion membranes by the Takenaka–Torikai method (T–T method). By controlling the amount of Ru in the alloys, the morphologies of the films varied from coarse particles to fine granules, some of which were fine enough to merge into the substrate. The response currents of all electrodes were proportional to hydrogen concentrations ranging from 100 to 1000ppm. The sensitivity of the Pt–Ru/Nafion electrodes was inversely proportional to the amount of Ru in the electrodes. However, both response and recovery times as well as sensitivity of the Pt80Ru20/Nafion electrode were improved while increasing the operational temperature. Binary electrodes that possessed a bi-functional mechanism for hydrogen oxidation were found to mitigate the impact of CO poisoning effectively only at low applied potential of 0.2V (vs. Ag/AgCl). Moreover, the Pt80Ru20/Nafion electrode entailed fast response and recovery times (90% response and recovery times) within 40s. [Copyright &y& Elsevier]