Electrochemical Oxidation of Cyanide Using Platinized Ti Electrodes

Abstract

The cyanide-containing effluents are dangerous ecological hazards and must be treated before discharging into the environment. Anodic oxidation is one of the best ways to degrade cyanides. Pt anodes as the most efficient material for the cyanide electrochemical degradation are widely used. However, these electrodes are too expensive for industrial purposes. In this work Ti electrodes covered with nano-sized Pt particle layer were prepared and used for the anodic oxidation of cyanide ions. Surface images of Ti electrodes and Ti electrodes covered with different thickness layer of Pt were compared and characterized by the atomic force microscopy (AFM). The products formed in the solution during the CNions electrooxidation were examined by the Raman spectroscopy. An electrochemical Fast Fourier transformation (FFT) impedance spectroscopy was used to estimate the parameters that reflect real surface roughness of Pt-modified Ti electrodes.

Carbon-Nitrogen Bond Formation on Cu Electrodes During Co2 Reduction in No3- Solution

“…3b). In excess of CN − in aqueous solution, CuCN can form higher, soluble complexes, generalized as Cu(CN) n (n−1) (n = 2, 3, 4), which structure depends on the CN − /Cu ratio 53 . At higher CN − concentration, the Raman signals of Cu 2 O decrease in intensity (Supplementary Figure S8), which proves chemical reaction of CN − to be likely with (surface) copper oxide, forming higher CuCN-complexes 54 .…”

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

“…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].…”

“…Therefore, it is complicated to choose an appropriate potential value for the effective platinization of a glass|Ti electrode from the voltammetric data (Figure 4). Previous investigations [18][19][20][21]29] suggest that by using hexachloroplatinate electrolytes, high-quality Pt coatings can be deposited galvanostatically over a wide range of cathodic current densities (from −1.5 mA cm −2 to −35 mA cm −2 ).…”

“…In our case, the potential of −0.6 V (vs. Ag|AgCl, KClsat), corresponding to an electrode current of approximately −2.0 mA (Figure 4), was chosen as the potential for microparticle growth (E2), while the short polarization pulse at −1.5 V was chosen as the potential (E1) to induce nucleation of Pt on the glass|Ti substrate. Under these conditions, a Pt layer with a theoretical thickness of 500 nm was deposited on the electrode, while our previous research [19,21] showed that a Ti electrode coated with a Pt layer thicker than 400 nm is an effective anode for the electrochemical oxidation of cyanide ions. (Equation ( 5)):…”

Corrosion characteristics of ZnNiCo ternary alloy electrochemically deposited by using different anodes

“…U okviru ovoga rada nisu vršena određivanja vrijednosti prenapona izdvajanja kiseonika na korištenim anodama. Dosadašnja istraživanja u primjeni različitih anodnih materijala su pokazala različite vrijednosti anodnog prenapona izdvajanja kiseonika [10][11][12][13][14][15][16].…”