Recyclable PhotoFuel Cell for Use of Acidic Water as a Medium
Yuta Ogura, Mao Yoshiba, and Yasuo Izumi,
Oil & Gas Science and Technology, 70(5), 853-862 (2015). DOI: 10.2516/ogst/2015031[The PDF file]
We reported a new PhotoFuel Cell (PFC) comprising two photocatalysts for use of acidic water as a recyclable medium. Nitrogen and oxygen flow was required in the photoanode and photocathode, respectively. In this study, we developed a gas-circulating PFC that needs no gas supply from outside. In the gas-circulating PFC, the reverse reaction of water oxidation at the anode was prevented by the gas flow of photogenerated O2 from the anode to the cathode inside the PFC. The gas-circulating PFC accommodated an organic solvent layer over the aqueous electrolyte for the anode, and also a vent hole in the upper part of the Proton-Conducting Polymer (PCP) film. O2 transferred from the anode electrolyte to the organic solvent due to the solubility difference between the HCl solution and organic solvent. O2 transfer from the gas phase in the anode to that in the cathode was achieved by the vent hole in the PCP film due to the pressure difference due to the progress of the reaction. By the addition of a hexane layer to the anode of the PFC, it was demonstrated to achieve a photocurrent value of 69.7 μA per 1.3 cm2 of photocatalysts. However, in the stability tests for more than 7 h, the small amount of remaining O2 in the electrolyte (2.85 μmol L−1) exhibited serious effects on the PFC performance. The ISC, VOC and PMax values of the gas-circulating PFC were 29.2 μA, 1.18 V and 6.10 μW, that were 40%, 74% and 44%, respectively, of those for a N2 and O2 flow-type PFC. Apparently, photocurrents were dramatically suppressed by the reverse reaction at the photoanode in the extended tests for the gas-circulating PFC.
Chiba University > Graduate School of Science > Department of Chemistry > Dr. Yasuo Izumi Group