On the pseudocapacitive behavior of nanostructured molybdenum oxide

Nanostructured molybdenum oxide was potentiodynamically deposited onto a stainless steel surface from an aqueous bath by cycling the potential between 0 and -0.75 V vs. Ag/AgCl. The deposit consisted of particulates in the range of 30 to 80 nm. Electrochemical studies under galvanostatic charge/discharge and also impedance spectroscopy revealed capacitive behavior in the potential range of -0.3 to -0.55 V vs. Ag/AgCl with the value of 477 F g(-1) at 0.1 mA/cm(2). An equivalent circuit comprising of three parallel branches consisting of double-layer capacitance, Warburg impedance, and a constant phase element signifying pseudo-capacitance each coupled with their corresponding resistances was fitted to the experimental findings, and the magnitudes of the elements were derived.