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Diffusion Effect On The Anodic Reactions Of Tungsten, Mustafa Anik, Tuba Cansizoğlu, Si̇nem Çevi̇k

Turkish Journal of Chemistry

Potentiodynamic and potentiostatic polarizations, and a rotating disk electrode technique were used to study the influence of diffusion on the anodic reactions of tungsten (W) in a broad pH range (\sim 0.3--13.5) in H_3PO_4 buffered solutions. The anodic current was controlled totally by the kinetics of H^+ -assisted dissolution below pH 1 (Region A). At around pH 2.5 (Region B), in addition to the kinetics of H_2O-assisted dissolution, specimen rotation had an effect on the current. This observation was attributed mainly to the physical damage to an oxide phase by hydrodynamic effects and partly to the diffusion of surface H_2WO_4(aq) …