Abstract
Nanostructured metal oxide semiconductors have shown outstanding performances in photoelectrochemical (PEC) water splitting, but limitations in light harvesting and charge collection have necessitated further advances in photoelectrode design. Herein, we propose anodized Fe foams (AFFs) with multidimensional nano/micro-architectures as a highly efficient photoelectrode for PEC water splitting. Fe foams fabricated by freeze-casting and sintering were electrochemically anodized and directly used as photoanodes. We verified the superiority of our design concept by achieving an unprecedented photocurrent density in PEC water splitting over 5 mA cm−2 before the dark current onset, which originated from the large surface area and low electrical resistance of the AFFs. A photocurrent of over 6.8 mA cm−2 and an accordingly high incident photon-to-current efficiency of over 50 % at 400 nm were achieved with incorporation of Co oxygen evolution catalysts. In addition, research opportunities for further advances by structual and compositional modifications are discussed, which can resolve the low fill factoring behavior and improve the overall performance.
Original language | English (US) |
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Pages (from-to) | 6583-6588 |
Number of pages | 6 |
Journal | Angewandte Chemie - International Edition |
Volume | 56 |
Issue number | 23 |
DOIs | |
State | Published - Jun 1 2017 |
Funding
Y.-E.S. acknowledges financial support from the Institute for Basic Science (IBS) in the Republic of Korea (Project Code: IBS-R006-G1). H.C. acknowledges supports from the Basic Science Research Program (2014R1A2A1A11052513) and Priority (2012-0006680) Research Centers Program through the National Research Foundation (NRF) of the Republic of Korea.
Keywords
- anodization
- iron oxide
- metal foam
- photoelectrochemistry
- water splitting
ASJC Scopus subject areas
- General Chemistry
- Catalysis