Detection of hydroxyl radicals in sonoelectrochemical system

We established an efficient method to trap the hydroxyl radicals (center dot OH) derived from the sonoelectrochemical system, the model compound crystal violet was used as a scavenger. Parameters affecting the trapping reaction, such as reaction time, electrolyte, applied voltage, power, and solution pH, were investigated. The dynamics model was used to analyze the reaction kinetics and the origin of center dot OH. The detection method is stable and accurate, comparing with the single electrochemical and ultrasonic systems, more center dot OH could be trapped in the sonoelectrochemical system; the higher the concentration of the scavenger, the more center dot OH is captured; the center dot OH is promoted to generate in the alkaline conditions; appropriate electrolyte concentration and voltage will enhance the center dot OH yields by increasing the current efficiency; inhibitors can significantly reduce the yields of center dot OH, inorganic inhibitors have better removal effect than organic inhibitors on the center dot OH; the enhancement of power is beneficial to the generation of cavitation effect increasing free radical production, it is not conducive to generate center dot OH when the power is strengthened to a certain degree; the center dot OH may be produced by the decomposition of water molecules and the oxidation of OH in the system; the process follows first-order reaction kinetics with good linearity.