Zhou Weide, Xue Ziqian, Liu Qinglin, Li Yinle, Hu Jianqiang, Li Guangqin
College of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou, 510640, Guangdong, P. R. China.
MOE Laboratory of Bioinorganic and Synthetic Chemistry Lehn Institute of Functional Materials, School of Chemistry, Sun Yat-Sen University, Guangzhou, 510275, P. R. China.
ChemSusChem. 2020 Nov 6;13(21):5647-5653. doi: 10.1002/cssc.202001230. Epub 2020 Sep 9.
Developing earth-abundant and high-performance electrocatalysts for water splitting has long been a vital research in energy conversion field. Herein, we report the preparation of a series of trimetallic uniform Mn Fe Ni-MOF-74 films in-situ grown on nickel foam, which can be utilized as bifunctional electrocatalysts towards overall water splitting in alkaline media. The introduction of Mn can simultaneously regulate the morphology of MOF-74 to form uniform film and modulate electronic structure of Fe to form more Fe(II)-O-Fe(III) motifs, which is conducive to the exposure of active sites and stabilizing high-valent metal sites. The optimized Mn Fe Ni-MOF-74 film electrode showed excellent electrocatalytic performance, affording a current density of 10 mA ⋅ cm at an overpotential of 99 mV for HER and 100 mA ⋅ cm at an overpotential of 267 mV for OER, respectively. Assembled as an electrolyser, Mn Fe Ni-MOF-74 film electrode exhibited excellent performance towards overall water splitting, with ultralow overpotential of 245 and 462 mV to achieve current density of 10 and 100 mA ⋅ cm , respectively. This work provides a new view to develop multi-metal MOF-based electrocatalysts.
开发用于水分解的储量丰富且高性能的电催化剂长期以来一直是能源转换领域的一项重要研究。在此，我们报道了一系列在泡沫镍上原位生长的三金属均匀Mn Fe Ni-MOF-74薄膜的制备，其可作为碱性介质中全水解的双功能电催化剂。Mn的引入可以同时调节MOF-74的形貌以形成均匀薄膜，并调节Fe的电子结构以形成更多的Fe(II)-O-Fe(III) motif，这有利于活性位点的暴露和高价金属位点的稳定。优化后的Mn Fe Ni-MOF-74薄膜电极表现出优异的电催化性能，在HER的过电位为99 mV时提供10 mA·cm的电流密度，在OER的过电位为267 mV时提供100 mA·cm的电流密度。作为电解槽组装时，Mn Fe Ni-MOF-74薄膜电极在全水解方面表现出优异的性能，分别在245和462 mV的超低过电位下实现10和100 mA·cm的电流密度。这项工作为开发多金属MOF基电催化剂提供了新的视角。
