Photoinduced processes of hydrogen peroxide formation and decomposition and their role in photosynthesis and biosphere origin

Processes of mutual photocatalytic transformation of O-2 and H2O2 in aqueous suspensions of chlorophyll and phthalocyanine immobilized on silica gel were investigated with application to the problem of the origin and evolution of the biosphere. It was demonstrated that chlorophyll affects the processes of H2O2 generation in water saturated in air oxygen and H2O2 decomposition in water upon illumination. The efficiency of these photocatalytic processes was shown to depend on pH of the medium and the amount of the pigment coating the substrate surface. The formation of organic products was detected at the irradiation of the suspensions of chlorophyll (phthalocyanine)/silica gel/water containing H2O2 and an inorganic carbon source.