Enhancement of OH radical formation during ultrasonic cavitation in water with an Ar-CO2 mixture

When a small amount CO2 was introduced into a pure Ar system, an enhancement of sonochemical formation of H2O2 was observed. At low CO2 volume fractions in the Ar-CO2 gas mixture, the concentration of dissolved gas in the solution increased due to the higher solubility of CO2 in water. The greater amount of dissolved gas nuclei leaded to an increase in the number of cavitation bubbles, resulting in the enhancement of OH radical formation.