ELECTROCHEMICAL STUDIES OF THE REDOX BEHAVIOR OF ANTIMONY IONS IN SODIUM-BORATE AND SILICATE MELTS

An electrochemical study of antimony ions doped in sodium berate and s ilicate glass melts was investigated by differential pulse voltammetry at various temperatures, by which Sb5+-Sb3+ redox reactions were obse rved. The half wave potentials for reduction of Sb5+ to Sb3+ shifted t oward negative values with increasing Na2O content of the glass-formin g liquids and with decreasing temperature. Substitution of Na2O by CaO in sodium silicate liquids shifted the half wave potential to the pos itive side. These results correspond to an increase of the content of pentavalent antimony ions with an increase of the basicity of the glas s-forming liquids.