Selective selenization of mixed-linker Ni-MOFs: NiSe2@NC core-shell nano-octahedrons with tunable interfacial electronic structure for hydrogen evolution reaction
Selective selenization of mixed-linker Ni-MOFs: NiSe2@NC core-shell nano-octahedrons with tunable interfacial electronic structure for hydrogen evolution reaction
复制标题
混合连接体Ni-MOFs的选择性硒化：具有可调界面电子结构的NiSe2@NC核壳纳米八面体用于析氢反应
DOI：
10.1016/j.apcatb.2020.118976
复制
发表时间：
2020-09-05
影响因子：
22.1
通讯作者：
Sun, Daofeng
中科院分区：
文献类型：
--
作者：
Huang, Zhaodi;Yuan, Shuai;Sun, Daofeng
用杂原子掺杂的碳材料调整催化剂的电子结构有望获得更高的电催化性能，但挑战仍然存在于界面结构的控制上。利用高度可调的金属有机骨架(MOF)模板，成功地合成了界面结构可控的NiSe2@N掺杂碳(NiSe2@NC)核-壳纳米八面体，并对其析氢性能进行了优化。混合连接体Ni-MOF的选择性硒化允许阴离子羧酸盐配体被Se-2(2-)取代，同时将中性N配位配体捕获到NiSe2纳米晶中。N-配体进一步碳化嵌入NiSe2纳米晶，得到NiSe2@NC核壳纳米八面体，表面覆盖着超薄的N掺杂碳壳。通过改变MOF前驱体中的N配位配体来控制催化剂中的N物种，得到了优化的HER催化剂，在10 mA cm-2时具有162 mV的小过电位，在1.0M KOH溶液中具有良好的长期稳定性(长达40h)。实验定义了吡啶-N与其活性之间的强相关性，并用密度泛函理论进行了解释。
Tuning the electronic structures of catalysts with heteroatom-doped carbon materials promises advanced electrocatalytic performance, but challenge remains in the control of interface structures. Taking advantage of the highly tunable metal-organic framework (MOF) templates, NiSe2@N-doped carbon (NiSe2@NC) core-shell nano-octahedrons with well controlled interface structures were successfully synthesized and optimized for the hydrogen evolution reaction (HER). Selective selenization of mixed-linker Ni-MOFs allows the replacement of anionic carboxylate ligands by Se-2(2-) while trapping neutral N-coordinating ligands in NiSe2 nanocrystals. Further carbonization of N-ligands embedded NiSe2 nanocrystals resulted in NiSe2@NC core-shell nano-octahedrons covered by ultrathin N-doped carbon shells. The N-species was controlled by changing N-coordinating ligands in MOF precursors, resulting in an optimized HER catalyst with a small overpotential of 162 mV at 10 mA cm(-2), and good long-term stability (up to 40 h) in 1.0 M KOH solution. A strong correlation between pyridinic-N and HER activity was experimentally defined and explained by DFT calculations.