Lyu Siliu, Guo Chenxi, Wang Jianing, Li Zhongjian, Yang Bin, Lei Lecheng, Wang Liping, Xiao Jianping, Zhang Tao, Hou Yang
Key Laboratory of Biomass Chemical Engineering of Ministry of Education, College of Chemical and Biological Engineering, Zhejiang University, 38 Zheda Road, Hangzhou, 310027, China.
Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, 1219 Zhongguan West Road, Ningbo, 315201, China.
Nat Commun. 2022 Oct 18;13(1):6171. doi: 10.1038/s41467-022-33847-z.
Oxygen evolution reaction (OER) plays a key role in many renewable energy technologies such as water splitting and metal-air batteries. Metal-organic frameworks (MOFs) are appealing to design efficient OER electrocatalysts, however, their intrinsic poor conductivity strongly hinders the activity. Here, we show a strategy to boost the OER activity of poor-conductive MOFs by confining them between graphene multilayers. The resultant NiFe-MOF//G gives a record-low overpotential of 106 mV to reach 10 mA cm and retains the activity over 150 h, which is in significant contrast to 399 mV of the pristine NiFe-MOF. We use X-ray absorption spectroscopy (XAS) and computations to demonstrate that the nanoconfinement from graphene multilayers not only forms highly reactive NiO-FeO distorted octahedral species in MOF structure but also lowers limiting potential for water oxidation reaction. We also demonstrate that the strategy is applicable to other MOFs of different structures to largely enhance their electrocatalytic activities.
析氧反应（OER）在许多可再生能源技术中起着关键作用，如水电解和金属空气电池。金属有机框架（MOF）对于设计高效的析氧反应电催化剂具有吸引力，然而，其固有的低导电性严重阻碍了活性。在此，我们展示了一种通过将低导电性的MOF限制在多层石墨烯之间来提高其析氧反应活性的策略。所得的NiFe-MOF//G在达到10 mA cm时具有创纪录的106 mV低过电位，并在150小时以上保持活性，这与原始NiFe-MOF的399 mV形成显著对比。我们使用X射线吸收光谱（XAS）和计算来证明，多层石墨烯的纳米限域不仅在MOF结构中形成了高活性的NiO-FeO扭曲八面体物种，而且降低了水氧化反应的极限电位。我们还证明了该策略适用于其他不同结构的MOF，以大幅提高其电催化活性。
