Ultrafine Dual-Phased Carbide Nanocrystals Confined in Porous Nitrogen-Doped Carbon Dodecahedrons for Efficient Hydrogen Evolution Reaction
Ultrafine Dual-Phased Carbide Nanocrystals Confined in Porous Nitrogen-Doped Carbon Dodecahedrons for Efficient Hydrogen Evolution Reaction
复制标题
DOI：
10.1002/adma.201900699
复制
发表时间：
2019-07-01
影响因子：
29.4
通讯作者：
Lou, Xiong Wen (David)
中科院分区：
文献类型：
--
作者：
Lu, Xue Feng;Yu, Le;Lou, Xiong Wen (David)
设计结构和组成受控的新型非贵金属电催化剂仍然是高效析氢反应（HER）的巨大挑战。本文报道了通过用钼酸盐或钨酸盐对功能性沸石咪唑酯骨架（ZIF-8）进行退火，合理合成限制在多孔氮掺杂碳十二面体（PNCD）中的超细碳化物纳米晶体。通过控制ZIF-8骨架中MO4单元（M = Mo或W）的取代量，可以获得限制在PNCD中的双相碳化物纳米晶（表示为MC-M2C/PNCDs），其对HER的活性优于单相MC/PNCDs和M2C/PNCDs。均匀分布的超细纳米晶体有利于活性位点的暴露。 PNCD 作为载体可促进电荷转移并保护纳米晶体在 HER 过程中免于聚集。此外，MC和M2C之间的强耦合相互作用为水解离和氢解吸提供了有利的位点。这项工作突出了一种通过纳米结构和成分工程探索高效电催化剂的新可行策略。
Designing novel non-noble electrocatalysts with controlled structures and composition remains a great challenge for efficient hydrogen evolution reaction (HER). Herein, a rational synthesis of ultrafine carbide nanocrystals confined in porous nitrogen-doped carbon dodecahedrons (PNCDs) by annealing functional zeolitic imidazolate framework (ZIF-8) with molybdate or tungstate is reported. By controlling the substitution amount of MO4 units (M = Mo or W) in the ZIF-8 framework, dual-phase carbide nanocrystals confined in PNCDs (denoted as MC-M2C/PNCDs) can be obtained, which exhibit superior activity toward the HER to the single-phased MC/PNCDs and M2C/PNCDs. The evenly distributed ultrafine nanocrystals favor the exposure of active sites. PNCDs as the support facilitate charge transfer and protect the nanocrystals from aggregation during the HER process. Moreover, the strong coupling interactions between MC and M2C provide beneficial sites for both water dissociation and hydrogen desorption. This work highlights a new feasible strategy to explore efficient electrocatalysts via engineering on nanostructure and composition.