Water oxidation reaction promoted by MIL-101(Fe) photoanode under visible light irradiation

作者：Lionet Zakary; Kamata Yusuke; Nishijima Shun; Toyao Takashi; Kim Tae Ho; Horiuchi Yu^*; Lee Soo Wohn; Matsuoka Masaya^*

来源：Research on Chemical Intermediates, 2018, 44(8): 4755-4764.

DOI：10.1007/s11164-018-3271-x

• Metal-organic framework
• Photoanode
• Water oxidation reaction
• Visible light

This work spotlights the recently discovered photoelectrocatalytic properties of iron-based metal-organic frameworks (MOFs) for water oxidation reaction (WOR) under visible light irradiation. The low efficiency of WOR is one of the biggest difficulties faced by photoelectrochemical solar energy conversion; the development of new photoanodes for WOR is greatly desired. In view of the fact that a higher efficiency for WOR was forecast thanks to the peculiar properties of MOFs, such as a highly ordered framework and homogenous porous structure, the photoelectrodes based on MIL-101(Fe) containing photo-active iron(III) clusters have been fabricated by using a drop-casting method and applied to photoelectrochemical water oxidation as photoanodes. XRD measurements revealed the successful formation of MIL-101(Fe) electrodes while retaining their framework structures. From the results of photoelectrochemical measurements, the optimal thickness of the MIL-101(Fe) electrodes was determined to be ca. 60 mu m, and the optimized MIL-101(Fe) electrode was found to promote photoelectrochemical WOR under visible light irradiation more efficiently than conventional alpha-Fe2O3 electrodes. Moreover, electrochemical impedance spectroscopy measurements demonstrated a lower resistance of charge transfer at the interface between the MOF surface and the electrolyte, resulting in better photoelectrochemical performance of the MIL-101(Fe) electrode.

• 出版日期2018-8