The catalytic activity of cysteine and cystine on the electroreduction of Bi(III) ions

The Effect of Protonated Ethionine Adsorption on Bi(III) Electroreduction in Chlorate(VII) Solutions with Varied Water Activity

“…2a). At the same time, reduction of peak width in the half of their height is observed which evidences the increase in reversibility of Bi(III) ion electroreduction with water activity drop [14][15][16][17]. Also, the picture of DC polarographic waves of Bi(III) ion electroreduction in the presence of ethionine [21] at all the studied concentrations of chlorates (VII) confirms the increase of electrode process reversibility.…”

“…It was found that an essential role in the electrode process acceleration is played by the ability of organic substance, undergoing adsorption on the electrode, to form complexes with the depolarizer in the circum electrode layer and location of the depolarizer reduction potential in the area of labile adsorption equilibrium of the organic substance [7,12]. The previous studies proved a significant effect of water activity [13], some amino acids [14][15][16][17], and change of the protonation of the amino acids on mechanism and kinetics of Bi(III) ions electroreduction [18][19][20][21], which developed the interpretation of the Bcap-pair^effect mechanism [11].…”

The Catalytic Impact of Ethionine on the Multi-Step Electroreduction of Bi(III) Ions in Chlorates(VII) Solutions

“…It has also been shown that the process of Bi(III) ion electroreduction is catalysed by methionine [15], cysteine and cystine [16,17]. Values of the standard rate constant k s [4] indicate that the catalytic effect of amino acids grows-in the order of cystine < methionine < cysteine-for chlorates(VII) with high water activity (from 1 to 4 mol dm…”

Investigation of the colloidal Cr2O3 removal possibilities from aqueous solution using the ionic polyamino acid block copolymers

“…In this situation the zeta potential changes are associated with the flat copolymer chains conformation and the resulting effects involving the electrolyte ions replacement in the Stern layer. In the other solution pH range (6)(7)(8)(9)(10), the increase in the copolymer concentration directly leads to the solid particles zeta potential growth. This follows from a larger number of the amino groups in the Cr 2 O 3 diffusion layer.…”

“…Interactions between various metal oxides and polymers containing only one type of the functional groups in the chain structure were repeatedly tested [5][6][7][8]. Searching for new stabilizers or suspension destabilizing agents have led to the increased interest in copolymers -the macromolecular compounds consisting of two (or more) types of structural units (monomers) of the specified character, connected via a covalent bond.…”