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Bulk-Heterojunction Electrocatalysts in Confined Geometry Boosting Stable,Acid/Alkaline-Universal Water Electrolysis |
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| Authors: | Gyu Yong Jang Sungsoon Kim Jinu Choi Jeonghwan Park SiEon An Jihyun Baek Yuzhe Li Tae-Kyung Liu Eugene Kim Jung Hwan Lee Haotian Wang MinJoong Kim Hyun-Seok Cho Xiaolin Zheng Jong Suk Yoo Kwanyong Seo Jong Hyeok Park |
| Affiliation: | 1. Department of Chemical and Biomolecular Engineering, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul, 03722 Republic of Korea Department of Chemical and Biomolecular Engineering, Rice University, Houston, TX, 77005 USA;2. Department of Chemical and Biomolecular Engineering, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul, 03722 Republic of Korea Department of Mechanical Engineering, Stanford University, Stanford, CA, 94305 USA;3. Department of Chemical Engineering, University of Seoul, 163 Seoulsiripdae-ro, Seoul, 02504 Republic of Korea;4. School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), 50 UNIST-gil, Ulsan, 44919 Republic of Korea;5. Hydrogen Research Department, Korea Institute of Energy Research, 152 Gajung-ro, Daejeon, 34129 Republic of Korea School of Mechanical Engineering, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul, 03722 South Korea;6. Department of Mechanical Engineering, Stanford University, Stanford, CA, 94305 USA;7. Department of Chemical and Biomolecular Engineering, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul, 03722 Republic of Korea;8. Department of Chemical and Biomolecular Engineering, Rice University, Houston, TX, 77005 USA Department of Materials Science and NanoEngineering, Rice University, Houston, TX, 77005 USA Department of Chemistry, Rice University, Houston, TX, 77005 USA;9. Hydrogen Research Department, Korea Institute of Energy Research, 152 Gajung-ro, Daejeon, 34129 Republic of Korea |
| Abstract: | Alkaline water splitting electrocatalysts have been studied for decades; however, many difficulties remain for commercialization, such as sluggish hydrogen evolution reaction (HER) kinetics and poor catalytic stability. Herein, by mimicking the bulk-heterojunction morphology of conventional organic solar cells, a uniform 10 nm scale nanocube is reported that consists of subnanometer-scale heterointerfaces between transition metal phosphides and oxides, which serves as an alkaline water splitting electrocatalyst; showing great performance and stability toward HER and oxygen evolution reaction (OER). Interestingly, the nanocube electrocatalyst reveals acid/alkaline independency from the synergistic effect of electrochemical HER (cobalt phosphide) and thermochemical water dissociation (cobalt oxide). From the spray coating process, nanocube electrocatalyst spreads uniformly on large scale (≈6.6 × 5.6 cm2) and is applied to alkaline water electrolyzers, stably delivering 600 mA cm−2 current for >100 h. The photovoltaic-electrochemical (PV-EC) system, including silicon PV cells, achieves 11.5% solar-to-hydrogen (STH) efficiency stably for >100 h. |
| Keywords: | acid/alkaline-universal alkaline water electrolysis electrocatalysis heterojunction transition metal phosphide unassisted water splitting |