Institute of Nanoscience and Nanotechnology, National Center for Scientific Research 'DEMOKRITOS', 15310, Athens, Greece.
Nanotechnology. 2019 Oct 11;30(41):415404. doi: 10.1088/1361-6528/ab3155. Epub 2019 Jul 11.
MoC/graphene heterostructures prepared by chemical vapor deposition have demonstrated excellent electrocatalytic activity in a hydrogen evolution reaction (HER). This is attributed to the high catalytic activity of MoC while the high electrical conductivity of graphene facilitates charge transfer. In the as-grown direct vertical order, graphene is placed above the MoC film. This reduces the catalytic activity of the heterostructure, since graphene in chemically inert. Here, a simple transfer method is proposed that results in the reverse order deposition of the heterostructure on the electrode. This method places graphene at the interface between MoC and the electrode, enhancing charge transfer between them, which results in an overpotential of 440 mV at 10 mA cm and corresponds to ∼65 mV overpotential reduction as compared to the direct heterostructure. At the same time, when a direct Cu/MoC/graphene junction with a Cu catalyst substrate is used as a working electrode, the improvement of the heterostructure HER activity is observed which is manifested in an overpotential of 275 mV at 10 mA cm with a correspondent ∼230 mV reduction. All above performances are accompanied with excellent endurance.
采用化学气相沉积法制备的 MoC/石墨烯杂化结构在析氢反应（HER）中表现出优异的电催化活性。这归因于 MoC 的高催化活性，而石墨烯的高导电性有利于电荷转移。在生长的直接垂直有序中，石墨烯位于 MoC 薄膜之上。这降低了杂化结构的催化活性，因为石墨烯是化学惰性的。在这里，提出了一种简单的转移方法，导致杂化结构在电极上的逆序沉积。该方法将石墨烯置于 MoC 和电极之间的界面处，增强了它们之间的电荷转移，从而导致在 10 mA cm 时的过电势为 440 mV，与直接杂化结构相比，过电势降低了约 65 mV。同时，当使用具有 Cu 催化剂基底的直接 Cu/MoC/石墨烯结作为工作电极时，观察到杂化结构 HER 活性的提高，在 10 mA cm 时的过电势为 275 mV，相应的降低约 230 mV。所有上述性能都伴随着出色的耐久性。
