School of Mechanical Engineering , Korea University , 145 Anam-ro , Seongbuk-gu , Seoul 02841 , South Korea.
Department of Mechanical Engineering , Stanford University , 440 Escondido Mall , Stanford , California 94305 , United States.
ACS Appl Mater Interfaces. 2019 Mar 20;11(11):10608-10615. doi: 10.1021/acsami.8b19064. Epub 2019 Mar 6.
In this work, we evaluated the oxygen evolution performance of cobalt oxide (CoO )-coated carbon fiber paper in electrochemical water splitting. For a uniform coating of CoO layers along the carbon fiber paper, the atomic layer deposition (ALD) technique was applied. We achieved a uniform and conformal coating of atomic-layer-deposited CoO (ALD-CoO ) on the carbon fiber paper. The overpotential for oxygen evolution measured for the optimized ALD-coated carbon fiber paper was as low as 343 mV at 10 mA cm, which is competitive with the activity of state-of-the-art CoO prepared on electrodes with large surface areas. Oxygen evolution is not enhanced after a critical thickness, about 28 nm in our study, is reached. The optimal thickness of the ALD-CoO film is dependent on two competing effects: the high oxidation state of cobalt ions in thicker CoO helps the oxygen evolution, whereas the introduction of a thick oxide coating decelerates the rate of charge transfer at the surface.
在这项工作中，我们评估了钴氧化物 (CoO) 涂层碳纤维纸在电化学水分解中的析氧性能。为了在碳纤维纸上均匀地涂层 CoO 层，应用了原子层沉积 (ALD) 技术。我们在碳纤维纸上实现了均匀且保形的原子层沉积 CoO (ALD-CoO) 涂层。优化的 ALD 涂层碳纤维纸的析氧过电势低至 343 mV 时 10 mA cm，与在具有大表面积的电极上制备的最先进的 CoO 的活性相当。在达到约 28 nm 的临界厚度后，析氧性能不会增强。最佳的 ALD-CoO 薄膜厚度取决于两个竞争效应：较厚 CoO 中钴离子的高氧化态有助于析氧，而厚氧化物涂层的引入则会降低表面处的电荷转移速率。
