Interfacing Photosystem I Reaction Centers with a Porous Antimony-Doped Tin Oxide Electrode to Perform Light Driven Redox Chemistry

Photoelectrochemical Water Oxidation by Cobalt Cytochrome C Integrated-ATO Photoanode

“…Leaching of the protein is also unlikely in this pH range because the pI of cyt c is 9.6. The data suggest that protonation and de-coordination of the axial histidine are involved in the catalysis, which have been previously postulated with other systems bearing pendant bases [5,46]. A similar pendantbase assisted water oxidation mechanism has been observed with a "xanthene-hangman" corrole complex ([Co III (bpfxc)], bpfxc = 5, 15-bis-(pentafluorophenyl)-10-(2,7-di-tert-butyl-5-carboxy-9,9-dimethyl-9H-xanthene-4-yl)corrole) that is active for electrocatalytic WO when immobilized in Nafion films, with a TOF close to 0.8 s −1 at 1.6 V vs. SHE applied potential (pH = 7) [22].…”

“…First, we optimized the pH, at which the photoelectrocatalytic studies with ATO-Cocyt c should be performed, within the pH range, where our protein is stable (5-9) [40,46]. The ability of the ATO-Co-cyt c photoanode to generate a photocurrent upon irradiation with a blue light is highest at pH 5 in citrate buffer, resulting in a photocurrent of 55 µA•cm −2 when 0.25 V of potential vs. RHE was applied (Figure 4).…”

“…A previously established sol−gel route for producing highly mesoporous ATO coatings was adapted for the fabrication of macroporous ATO coatings [26,38,40,45,46]. Briefly, a clear solution with 1.00 g of SnCl 4 •5H 2 O (Alfa Aesar, 98%) (Haverhill, MA, USA) and 0.05 g of SbCl 3 (Alfa Aesar, ≥99.9%) in 6.50 g of n-BuOH and 1.0 g of deionized water was prepared and cooled to about 4 • C in ice bath, and then transferred into an Ultra-Turrax tube drive with a rotor stator element.…”