Xu Huizhu, Ye Ke, Zhu Kai, Yin Jinling, Yan Jun, Wang Guiling, Cao Dianxue
Key Laboratory of Superlight Materials and Surface Technology of Ministry of Education, College of Materials Science and Chemical Engineering, Harbin Engineering University, Harbin 150001, China.
Dalton Trans. 2020 May 7;49(17):5646-5652. doi: 10.1039/d0dt00605j. Epub 2020 Apr 14.
Herein, a three-dimensional (3D) Ni/Fe bimetallic organic framework (MOF-Ni@MOF-Fe) with a structure of rhombus blocks on nanosheets is synthesized on Ni foam by a 2-step solvothermal method. After sulfide reaction, MOF-Ni@MOF-Fe-S is vulcanized by MOF-Ni@MOF-Fe with a structure of interwoven and folding nanosheets. Meanwhile, NiS is formed under the influence of iron. This special structure makes MOF-Ni@MOF-Fe-S to expose more active sites. MOF-Ni@MOF-Fe-S shows superior urea oxidation reaction (UOR) and hydrogen evolution reaction (HER) performance. When MOF-Ni@MOF-Fe-S is used as UOR and HER catalysts, it has low potentials of 1.347 V (vs. RHE) at 10 mA cm and 0.145 V (vs. RHE) at 10 mA cm in 1.0 M KOH with 0.5 M urea, respectively. MOF-Ni@MOF-Fe-S as a bifunctional electrode is assembled as an alkaline urea electrolyzer, showing catalytic activity at a low cell voltage of 1.539 V at 10 mA cm and excellent stability during 10 h chronopotentiometry analysis.
在此，通过两步溶剂热法在泡沫镍上合成了一种具有纳米片上菱形块结构的三维（3D）镍/铁双金属有机框架（MOF-Ni@MOF-Fe）。经过硫化反应后，MOF-Ni@MOF-Fe-S由具有交织和折叠纳米片结构的MOF-Ni@MOF-Fe硫化而成。同时，在铁的影响下形成了硫化镍。这种特殊结构使MOF-Ni@MOF-Fe-S暴露更多活性位点。MOF-Ni@MOF-Fe-S表现出优异的尿素氧化反应（UOR）和析氢反应（HER）性能。当MOF-Ni@MOF-Fe-S用作UOR和HER催化剂时，在含有0.5 M尿素的1.0 M KOH中，在10 mA cm²时的低电位分别为1.347 V（相对于可逆氢电极，RHE）和0.145 V（相对于RHE）。将MOF-Ni@MOF-Fe-S作为双功能电极组装成碱性尿素电解槽，在10 mA cm²时，在1.539 V的低电池电压下表现出催化活性，并且在10小时的计时电位分析过程中具有出色的稳定性。
