Effect of Elemental Composition on the Structure, Electrochemical Properties, and Ozone Production Activity of Ti/SnO2-Sb-Ni Electrodes Prepared by Thermal Pyrolysis Method

Abstract

Ti/SnO2-Sb-Ni electrodes with various Ni- and Sb-doping levels have been prepared by dip-coating thermal pyrolysis procedure, and their simultaneous electrochemical ozone production (EOP) and oxygen evolution reaction (OER) were investigated. The effects of electrode composition on the nanostructure, morphology, electrochemical behavior, kinetic parameters, and lifetime of the electrodes were systematically studied using X-ray diffraction, scanning electron microscopy, cyclic voltammetry, linear sweep voltammetry, and chronopotentiometry. Dissolved ozone was produced in a quartz cell and its concentration was monitored by in situ UV spectrophotometry. The presence of small amounts of Ni (Ni : Sn atomic ratio of 0.2 : 100) gives valuable characteristics to the electrodes such as increasing EOP activity and service life. Higher Ni concentrations increase the electrode film resistance and decrease its capacitance, roughness factor, and service life, while increasing Sb level up to 12 atom% improves the electrode performance with respect to these parameters. Nevertheless, the Sb/Sn atomic ratio of more than 2% reduces the EOP current efficiency in favor of OER. The optimum composition of the electrode for EOP was determined to be Sb/Sn and Ni/Sn atomic ratios of 2% and 0.2%, respectively. The highest current efficiency was 48.3% in 0.1 M H2SO4solution at room temperature.

Deposition efficiency in the preparation of ozone-producing nickel and antimony doped tin oxide anodes

“…An intriguing aspect of the material was that a very small concentration of nickel added to the mixed oxide yielded an electrode that made it possible to produce ozone at low anode potentials (2.2 V vs. Ag/AgCl) at room temperature and at relatively high current efficiencies (∼30 %) while the current efficiency was almost 0 % in the absence of nickel. Since then, several groups have studied the material and current efficiencies of up to 54 % at potentials below 3 V vs. Ag/AgCl have been reported [7,[10][11][12][13][14][15][16]. The minimum energy demand found so far is 18 kWh/kg O3 [7] which, to our knowledge, is the lowest value reported for the electrochemical formation of ozone and is moreover low enough to compete with the CCD process.…”

“…The metal salts SnCl45H2O, SbCl3 and NiCl26H2O were dissolved in alcohol to the molar ratios of 1000: (16)(17)(18)(19)(20):(2-6) (Sn:Sb:Ni) [7,[9][10][11][12][13]15]. This precursor solution is then coated on a pre-treated titanium substrate (foil or mesh) by brush, dip or spray coating.…”

“…The current efficiencies reported for the electrodes prepared in this fashion ranges from 24 to 54 %. The molar ratios mentioned are optimized for the generation of ozone (maximizing current efficiency) [7,9,15].…”

Experimental study and theoretical calculation on the conductivity and stability of praseodymium doped tin oxide electrode

“…Sumanta et al [9] synthesized Pt doped SnO 2 thin films on TCO (transparent conducting oxide) substrates, and it was used as electrode to oxidize methanol, the study revealed that Pt-SnO 2 electrode is more effective for methanol electro-oxidization than pure SnO 2 . Shekarchizade et al [10] prepared Ti/SnO 2 -Sb-Ni electrodes with various Ni-and Sb-doping levels by dip-coating thermal pyrolysis procedure, the results showed that the presence of appropriate amounts of Ni and Sb can improve the electrode performance, such as EOP activity, resistance, capacitance, roughness factor and service life. Dong et al [11] studied the conductivity and stability of Bi-doped SnO 2 electrode using electrochemical method and first principle calculation, it turned out that the conductivity and stability of Bi-doped SnO 2 electrode reached best when the doping ratio is 100:8.…”

A novel approach for textile dye degradation by zinc, iron–doped tin oxide/titanium moving anode

“…For Ti/SnO 2 -Sb 2 O 5 anode, 5 % of Sb dopant is an optimum concentration for electro-oxidation of 4-chlorophenol (Watts et al 2008). Addition of Ni onto TiO 2 /SnO 2 -Sb electrode yields satisfactory results (Shekarchizade and Amini 2011). Macroporous Sb-doped SnO 2 /TiO 2 nanotube electrodes have successfully been synthesized and found to display superior performance as a catalyst with regard to decreasing the toxicity of p-nitrophenol (Chai et al 2011).…”