State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology , Beijing 100029, People's Republic of China.
Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education, College of Chemistry, Beijing Normal University , Beijing 100875, People's Republic of China.
ACS Appl Mater Interfaces. 2017 Oct 25;9(42):36762-36771. doi: 10.1021/acsami.7b10338. Epub 2017 Oct 12.
Hydrogen generation from water splitting could be an alternative way to meet increasing energy demands while also balancing the impact of energy being supplied by fossil-based fuels. The efficacy of water splitting strongly depends on the performance of electrocatalysts. Herein, we report a unique space-confined earth-abundant electrocatalyst having the bifunctionality of simultaneous hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), leading to high-efficiency water splitting. Outperforming Pt/C or RuO catalysts, this mesoscopic, space-confined, bifunctional configuration is constructed from a monolithic zeolitic imidazolate framework@layered double hydroxide (ZIF@LDH) precursor on Ni foam. Such a confinement leads to a high dispersion of ultrafine CoO nanoparticles within the N-doped carbon matrix by temperature-dependent calcination of the ZIF@LDH. We demonstrate that the OER has an overpotential of 318 mV at a current density of 10 mA cm, while that of HER is -106 mV @ -10 mA cm. The voltage applied to a two-electrode cell for overall water splitting is 1.59 V to achieve a stable current density of 10 mA cm while using the monolithic catalyst as both the anode and the cathode. It is anticipated that our space-confined method, which focuses on earth-abundant elements with structural integrity, may provide a novel and economically sound strategy for practical energy conversion applications.
从水分解中产生氢气可能是一种替代方法，可以满足不断增长的能源需求，同时平衡由化石燃料供应的能源的影响。水分解的效率强烈依赖于电催化剂的性能。在此，我们报告了一种独特的空间受限的丰富地球电催化剂，具有同时进行析氢反应（HER）和析氧反应（OER）的双功能，从而实现高效水分解。这种介观、空间受限、双功能的结构由块状沸石咪唑酯骨架@层状双氢氧化物（ZIF@LDH）前体在 Ni 泡沫上构建，优于 Pt/C 或 RuO 催化剂。这种限制通过 ZIF@LDH 的温度依赖性煅烧导致超细 CoO 纳米颗粒在 N 掺杂碳基质中的高分散。我们证明，OER 在电流密度为 10 mA cm 时的过电位为 318 mV，而 HER 在 -106 mV @ -10 mA cm 时的过电位为 -106 mV。在使用整体催化剂作为阳极和阴极的情况下，施加到两电极电池以实现稳定的 10 mA cm 电流密度的总水分解的电压为 1.59 V。预计我们的空间受限方法，重点关注具有结构完整性的丰富地球元素，可能为实际的能量转换应用提供一种新颖且经济合理的策略。
