Study Of The Impact Of Ultrasound On The Electrochemical Process

The effects of ultrasound on gas evolution, mass transport and cathode electrodeposition were studied in the electrochemical reaction system with the key technique of ultrasound. The aim of the researches is to provide theoretical basic and technological parameters for the application of ultrasound to the electrochemical process.1. Oxygen evolution at the anode during the electrolysis of the aqueous solution with ultrasoundThe effect of ultrasound on oxygen evolution at the anode was studied in the electrolysis of 1.0 mol/L KOH aqueous solution. The polarization curves at the anode were obtained with and without ultrasound at several operating temperatures. The current density, the yield of oxygen and the current efficiency were discussed with a potentiostatic method under the influence of power ultrasound. The results indicate that the process of the oxygen evolution is affected by ultrasound. The current density in the presence of ultrasound is higher than that in the absence of ultrasound. The current density with ultrasound is 1.27-fold than that without ultrasound at the potential of 0.500V (vs. SCE) and at the temperature of 25 °C. The yield of oxygen under the action of ultrasound is higher than that under the silent condition, and that the ratio of yield of oxygen in the presence of ultrasound to that in the absence of ultrasound decreases from 1.37 to 1.20 at the potential of 1.000V(vs. SCE) when the temperature ranges from 25 °C to 55 °C. The current efficiencies with and without ultrasound are increased with increasing temperatures.2. The reaction rate for the electrochemical reduction of K3Fe(CN)6 to at both presence and absence power sonicationThe effects of ultrasound on the electrochemical reduction of K3Fe(CN)g to K4Fe(CN)6 were studied at several temperatures and reactant concentrations. The current-potential curves were measured in the presence of ultrasound and in the absence of ultrasound. The experimental results show that the current density is sharply increased under the action of ultrasound, and the effect of ultrasound on the current density in the mass-transfer-controlled region is higher than that in the non-mass-transfer-controlled region. The current density in the presence of ultrasound is 26-fold than that in the absence of ultrasound at the potential of 0.15Y(vs. SCE), but the limiting current density with ultrasound is 65-fold than that without ultrasound at the potential of -0.30V(v,s. SCE). The ratio of the limiting current density with ultrasound to that without ultrasound decreases from 68.4 to 54.0 with increasing operating temperatures from 25 °C to 65 °C because the effect of cavitation is decreased with increasing operating temperatures from 25 °C to 65 °C. The limiting current density increases with increasing concentrations and the limiting current densities are proportional to the concentrations of K3Fe(CN)6 in the presence of ultrasound or in the absence of ultrasound.3. The effects of ultrasound on the processes for the copper electrodepositionThe current-potential curves for copper electrodeposition were measured in the presence and in the absence of ultrasound. The effects of ultrasound on the crystal orientation and surface morphology were discussed in the copper electrochemical reduction. The experimental results show that the mass-transfer-controlled current density of the electrochemical reduction of copper ions is significantly increased in the presence of ultrasound. The influence of ultrasound on the average limiting current density decreases with the increasing temperature. The average current density in the presence of ultrasound is about 14.1-fold than that in the absence of ultrasound at 25 °C.Otherwise, the ratio of the current density with ultrasound to that without ultrasound is 8.4 at the temperature of 55°C. Ultrasound can change texture coefficient in the process of copper electrodeposition. The texture coefficient of 200 is improved with increasing time under the condition of ultrasonic irradiation. The electrodeposited grain size is also dec...