Photocatalytic activity of chlorophyll in hydrogen peroxide generation in water

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“…Furthermore, electron transfer from excited photosensitizer to oxygen to form the superoxide anion О 2 -which can produce hydrogen peroxide by the following reactions [59][60][61]:…”

Special Features of Singlet Oxygen Generation Photosensitized by Magnesium Complexes of Tetrapyrrolic Macrocycles

“…Immobilization of TPS on Sil was performed as described earlier. [9] The kinetics of oxidation of anthracene (An), followed by loss of optical density of its solutions at the absorption bands of λ max = 360 and 378 nm. The concentration of H 2 O 2 formed was determined by iodometric titration in combination with spectrophotometry.…”

“…The concentration of H 2 O 2 formed was determined by iodometric titration in combination with spectrophotometry. [9] Quantum yields (Φ) of formation of AnO 2 and H 2 O 2 were determined as the ratio of the number of formed molecules to the number of photons absorbed by the TPS in the initial fixed period of time. [12,13] The error of Φ determination was ±10%.…”

“…We have previously shown that Mg-Chl in the water systems photosensitizes formation of H 2 O 2 , and it was thermodynamically substantiated and experimentally confirmed that transformation of primary photogenerated 1 O 2 is the advantageous channel for the synthesis of H 2 O 2 . [9,31] • in acidic medium. [32] In this case, the following diffusion controlled reactions with known rate constants take place: [24] • ОН +…”

“…At the same time, there are mechanisms for effective decontamination of 1 O 2 by chlorins [2] and transformation of 1 O 2 in a physiologically important hydrogen peroxide in the chloroplasts. [9] In this paper features of 1 O 2 generation photosensitized by magnesium complexes of TPS and accumulation of products of 1 O 2 transformation in organic (for example, anthracene) and aqueous phases were studied.…”