Hybrid 2D Dual-Metal-Organic Frameworks for Enhanced Water Oxidation Catalysis
Hybrid 2D Dual-Metal-Organic Frameworks for Enhanced Water Oxidation Catalysis
复制标题
用于增强水氧化催化的混合二维双金属有机框架
DOI：
10.1002/adfm.201801554
复制
发表时间：
2018-06-27
影响因子：
19
通讯作者：
Dou, Shi Xue
中科院分区：
文献类型：
--
作者：
Rui, Kun;Zhao, Guoqiang;Dou, Shi Xue
金属有机骨架(MOF)及其衍生的纳米结构是近年来出现的一种很有前途的电催化催化剂。本论文合成了Fe-MOF纳米颗粒修饰的2D MOF纳米片，并对其在碱性介质中的水氧化催化性能进行了评价。通过将电化学惰性的Fe-MOF纳米粒子引入到活性2D MOF纳米片上，证明了催化活性的显著提高。对于活性的Ni-MOF纳米片(Ni-MOF@Fe-MOF)，在1mKOH中的过电位为265 mV，电流密度达到10 mA cm(-2)，杂化后的过电位降低了约100 mV，这是由于Ni活性中心和Fe物种之间的协同作用。在活性NiCo-MOF纳米片中也成功地展示了类似的性能改进。更重要的是，揭示了Ni-MOF@Fe-MOF杂化催化剂中真实的催化活性物种。研究发现，在析氧反应(OER)过程中，原位生成了NiO纳米颗粒(约5 nm)，并作为OER活性中心和多孔纳米片催化剂的构件。这些发现为理解MOF基水氧化催化催化剂提供了新的见解，也为设计高效的MOF衍生纳米电催化结构提供了启示。
Metal-organic frameworks (MOFs) and MOF-derived nanostructures are recently emerging as promising catalysts for electrocatalysis applications. Herein, 2D MOFs nanosheets decorated with Fe-MOF nanoparticles are synthesized and evaluated as the catalysts for water oxidation catalysis in alkaline medium. A dramatic enhancement of the catalytic activity is demonstrated by introduction of electrochemically inert Fe-MOF nanoparticles onto active 2D MOFs nanosheets. In the case of active Ni-MOF nanosheets (Ni-MOF@Fe-MOF), the overpotential is 265 mV to reach a current density of 10 mA cm(-2) in 1 m KOH, which is lowered by approximate to 100 mV after hybridization due to the 2D nanosheet morphology and the synergistic effect between Ni active centers and Fe species. Similar performance improvement is also successfully demonstrated in the active NiCo-MOF nanosheets. More importantly, the real catalytic active species in the hybrid Ni-MOF@Fe-MOF catalyst are unraveled. It is found that, NiO nanograins (approximate to 5 nm) are formed in situ during oxygen evolution reaction (OER) process and act as OER active centers as well as building blocks of the porous nanosheet catalysts. These findings provide new insights into understanding MOF-based catalysts for water oxidation catalysis, and also shed light on designing highly efficient MOF-derived nanostructures for electrocatalysis.