REGULARITIES OF Na2MoO4 ONTO Se|SnO2|GLASS SURFACE

Abstract

Na₂MoO₄ electrochemical reduction from 0.22 mol/dm³ sodium citrate supporting solution was investigated by the cyclic voltammetry, X-ray photoelectron spectroscopy and lateral force microscopy techniques. Experimental results have indicated that molybdenum oxide is initially deposited on the Se|SnO₂|glass surface in a potential range from -0.20 V to -0.80 V. XPS analysis exhibited the molybdenum oxide stoichiometry of 2.9.

The nucleation mechanism of MoO_x onto Se|SnO₂|glass surface was investigated by the current transient technique. The deposition transients analyzed in the non-dimensional plots I₂/I²_m=f(t/t_m) and I₂/I²_m=f(t/t_m)² have shown that MoO_x nucleates according to a progressive mechanism. The nucleation rate depends on Na₂MoO₄ concentration in the supporting electrolyte and on the deposition potential.