Influence of AlOOH nanoparticles on the oxidation of iodide by persulphate

The oxidation of iodide by persulphate has been studied in the presence of the AlOOH nanoparticles. The rate of this reaction is significantly higher in the presence of the AlOOH nanoparticles than when it takes place in an aqueous medium. The dependence of the rate constant on the AlOOH content, temperature, ionic strength and pH has been examined. The results are interpreted in terms of electrostatic interaction between negatively charged reactant species and surface charge of the AlOOH nanoparticles. The sensitivity of the rate constant to the pH provides convenient method for precise detection of the point of zero charge of dispersed material.