Photochemistry of ZnO in Heptane: Detection by Oxygen Uptake and Spin Trapping

Article abstract of DOI:10.1021/j100343a071

The utilization of a Clark O2 electrode to monitor O2 consumption in low-dielectric, aliphatic solvents has been succesfully realized.Thus, the consumption of oxygen in ZnO dispersion in heptane could be readily monitored upon photoexcitation of the ZnO.Addition of an amine as electron donor enhanced this O2 uptake with the rate of O2 uptake being directly proportional to the concentration of added amine.ESR results from use of the technique of spin trapping revealed that a nitrogen-centered radical was photogenerated in the presence of amines.Electrochemical oxidation of the amine in the presence of the spin trap provided evidence that the amine cation radical is the species being trapped.The mechanism of this reaction is discussed.