Optimization of Photoanodes for Photocatalytic Water Oxidation by Combining a Heterogenized Iridium Water‐Oxidation Catalyst with a High‐Potential Porphyrin Photosensitizer

• DOI: 10.1002/cssc.201701693
• Publication Date: 2017-09-06T14:54:41Z
• Authors: Kelly L. Materna; Jianbing Jiang; Kevin P. Regan; Charles A. Schmut...; Robert H. Crabtree; Gary W. Brudvig
• Keywords: Photosensitizing Agents; Porphyrins; Water; 02 engineering and technology; Iridium; Photochemical Processes; 7. Clean energy; Catalysis; Solar Energy; Coloring Agents; 0210 nano-technology; Electrodes; Oxidation-Reduction

The development of water-splitting dye-sensitized photoelectrochemical cells has gained interest owing to their ability generate renewable fuels from solar energy. In this study, photoanodes were assembled a SnO2 film sensitized with combination high-potential CF3 -substituted porphyrin dye tetrahydropyranyl-protected hydroxamic acid surface-anchoring group and Cp*Ir (Cp*=pentamethylcyclopentadienyl) water-oxidation catalyst containing silatrane anchoring group. dye/catalyst ratios varied 2:1 32:1 optimize the photocatalytic water oxidation. Photoelectrochemical measurements showed not only more stable reproducible photocurrents for lower but also improved photostability. O2 production was confirmed in real time over 20 h period Clark electrode. Photoanodes prepared 8:1 sensitization solutions provided most active electrodes oxidation performed approximately 30-35 turnovers h.