Electrooxidation of cyanide ion on a platinized Ti electrode

Titanium–Platinum Thin Films as a Tool for the Electrooxidation of Cyanide

“…In general, anodes for the electrooxidation of organics are divided into "non-active" anodes (such as boron-doped diamond (BDD) or SnO 2 -Sb [24]) and "active" anodes (such as transition metals and their oxides [20,21]). "Non-active" anodes are used for the indirect electrooxidation of cyanide, generating hydroxyl radicals and other oxidizing species that oxidize CN − ions at high potentials while inhibiting the oxygen evolution reaction (OER) [25].…”

“…"Active" anodes may be considered less efficient for direct electrooxidation because of their high activity towards competing OER. However, it has been shown that "active" anodes can be used for both direct and indirect electrooxidation of cyanide via intermediate hydroxyl radicals [20]. The generally accepted mechanism in the scientific community for the electrooxidation of cyanide is [26,27]:…”

“…Previous efforts have used platinum, stainless steel, graphite, lead, etc., anodes [20,21,[28][29][30][31][32][33][34][35][36] for the electrooxidation of cyanide. Platinum, with current efficiencies up to 80%, is one of the most efficient electrode materials [20,21]. However, Pt is an expensive metal and with the amount of cyanide waste that exists, we need to find cheaper alternatives.…”

“…However, Pt is an expensive metal and with the amount of cyanide waste that exists, we need to find cheaper alternatives. It was suggested that a titanium plate electrode electrochemically coated with a thin layer of Pt could achieve an almost complete oxidation of CN − (from 0.1 M to 0.16 mM), so platinized Ti electrodes could be used instead of Pt plate electrodes [18][19][20][21]37]. Electrochemical Pt deposition on conductive surfaces seems to be a promising and environmentally friendly technique, as it can be performed using various Pt salts and/or Pt-containing wastes instead of pure Pt, which is expensive [38].…”

“…40%) are lower than those obtained Coatings 2023, 13, 1821 3 of 18 with metallurgic Pt electrodes (approx. 80%) [20,21]. Therefore, a critical question remains as to how to produce electrodes with equal or better efficiency for cyanide oxidation.…”