MECHANISTIC INTERPRETATIONS OF THE DYE-SENSITIZED FORMATION OF HYDROGEN PEROXIDE IN AN AQUEOUS SOLUTION.

Article abstract of DOI:10.1246/bcsj.53.2716

Kinetic studies of the photosensitized formation of hydrogen peroxide and hyperoxide ions in a mixed aqueous solution of eosine, oxygen, and EDTA have been attempted on the basis of a switch-over of the primary processes, i. e. , the so-called DD, DR, and DO mechanisms. The rate constants for reactions of E** plus . . . E** minus and E** plus . . . O//2** minus intermediates with oxygen and EDTA were obtained. The yield of hydrogen peroxide via the DO-initated mechanism was enhanced as much as one order of magnitude ( approximately equals 0. 012) by the addition of 0. 15 mol dm** minus **3 of sodium borate or sodium carbonate. The maximum yield, 0. 08, of hydrogen peroxide was obtained in an aerated aqueous solution of 1. 0 multiplied by 10** minus **4 mol dm** minus **3 of eosine, 5. 0 multiplied by 10** minus **2 mol dm** minus **3 of EDTA, and 8. 8 multiplied by 10** minus **2 mol dm** minus **3 of sodium borate.