Silver Selenide as a Potential Electro-catalyst for L-Ascorbic Acid Electro-oxidation in Alkaline Solution

摘要

Cathodically deposited Ag2Se, to form a 1-μm-thick film, characterized by energy dispersive X-ray analysis and scanning electron microscopy, showed high electro-catalytic activity for L-ascorbic acid oxidation in alkaline solution. The onset of the process was about 80 mV cathodic of that previously observed on Ag under the same conditions and far superior over glassy carbon and Pt. The values of the exchange current density, standard heterogeneous rate constant, and transfer coefficient of the reaction were 1.65 x 10~(-4) A cm~(-2), 4.35x10~(-7) cm s~(-1), and 0.60, respectively. Diffusion coefficient of L-ascorbate di-anion was also measured and was around 7.00 x 10~(-6) cm~2 s~(-1).