Zheng Hang-Bo, Chen Hui-Hui, Wang Yuan-Li, Gao Peng-Zhao, Liu Xiao-Pan, Rebrov Evgeny V
College of Materials Science and Engineering, Hunan University, Changsha, Hunan 410082, China.
Hunan Province Key Laboratory for Advanced Carbon Materials and Applied Technology, Hunan University, Changsha, Hunan 410082, China.
ACS Appl Mater Interfaces. 2020 Oct 14;12(41):45987-45996. doi: 10.1021/acsami.0c11816. Epub 2020 Sep 30.
As an ideal hydrogen production route, electrolyzed water still faces the challenges of high cost of noble-metal electrocatalysts and low performance of non-noble-metal catalysts in scalable applications. Recently, introduction of external fields (such as magnetic fields, light fields, etc.) to improve the electrocatalytic water splitting performance of non-noble-metal catalysts has attracted great attention due to their simplicity. Here, a simple method for preparing magnetic superstructure (NiFeO@MOF-74) is described, and the hydrogen evolution reaction (HER) behavior of its carbonized derivative, a ferromagnetic superstructure, is revealed in a wide range of applied voltage under an AC magnetic field. The overpotential (@10 mA cm) required for the HER of the obtained ferromagnetic superstructure in 1 M KOH was reduced by 31 mV (7.7%) when a much small AC magnetic field (only 2.3 mT) is applied. Surprisingly, the promotion effect of the AC magnetic field is not monotonically increasing with the increase of the applied voltage or the strength of AC magnetic field, but increasing first, then weakening. This unusual behavior is believed to be mainly caused by the enhanced induced electromotive force and the additional energy by the applied AC magnetic field. This discovery provides a new idea for adjusting the performance of electrocatalytic reactions.
作为一种理想的制氢途径，电解水在可扩展应用中仍面临着贵金属电催化剂成本高和非贵金属催化剂性能低的挑战。最近，引入外部场（如磁场、光场等）以提高非贵金属催化剂的电催化水分解性能因其简便性而备受关注。在此，描述了一种制备磁性超结构（NiFeO@MOF-74）的简单方法，并揭示了其碳化衍生物（一种铁磁超结构）在交流磁场下宽范围施加电压下的析氢反应（HER）行为。当施加非常小的交流磁场（仅2.3 mT）时，所获得的铁磁超结构在1 M KOH中HER所需的过电位（@10 mA cm）降低了31 mV（7.7%）。令人惊讶的是，交流磁场的促进作用并非随着施加电压或交流磁场强度的增加而单调增加，而是先增加，然后减弱。这种异常行为被认为主要是由施加的交流磁场增强的感应电动势和额外能量引起的。这一发现为调节电催化反应性能提供了新思路。
