Pi Chaoran, Li Xingxing, Zhang Xuming, Song Hao, Zheng Yang, Gao Biao, Kızılaslan Abdulkadir, Chu Paul K, Huo Kaifu
Wuhan National Laboratory for Optoelectronics (WNLO), School of Optical and Electronic Information Huazhong University of Science and Technology, Wuhan, 430074, P. R. China.
The State Key Laboratory of Refractories and Metallurgy, Institute of Advanced Materials and Nanotechnology, Wuhan University of Science and Technology, Wuhan, 430081, P. R. China.
Small. 2022 Jun;18(22):e2201137. doi: 10.1002/smll.202201137. Epub 2022 May 8.
Cost-effective electrocatalysts for the hydrogen evolution reaction (HER) spanning a wide pH range are highly desirable but still challenging for hydrogen production via electrochemical water splitting. Herein, Mo N -MoS heterojunction nanosheets prepared on hollow carbon nanoribbons (Mo N -MoS /HCNRs) are designed as Mott-Schottky electrocatalysts for efficient pH-universal HER. The in-plane Mo N -MoS Mott-Schottky heterointerface induces electron redistribution and a built-in electric field, which effectively activates the inert MoS basal planes to intrinsically increase the electrocatalytic activity, improve electronic conductivity, and boost water dissociation activity. Moreover, the vertical Mo N -MoS nanosheets provide more activated sites for the electrochemical reaction and facilitate mass/electrolyte transport, while the tightly coupled HCNRs substrate and metallic Mo N provide fast electron transfer paths. Consequently, the Mo N -MoS /HCNRs electrocatalyst delivers excellent pH-universal HER performances exemplified by ultralow overpotentials of 57, 59, and 53 mV at a current density of 10 mA cm in acidic, neutral, and alkaline electrolytes with Tafel slopes of 38.4, 43.5, and 37.9 mV dec , respectively, which are superior to those of the reported MoS -based catalysts and outperform Pt in overall water splitting. This work proposes a new strategy to construct an in-plane heterointerface on the nanoscale and provides fresh insights into the HER electrocatalytic mechanism of MoS -based heterostructures.
在广泛的pH范围内具有成本效益的析氢反应（HER）电催化剂是非常理想的，但对于通过电化学水分解制氢仍然具有挑战性。在此，在中空碳纳米带（MoN - MoS /HCNRs）上制备的MoN - MoS异质结纳米片被设计为用于高效pH通用HER的莫特-肖特基电催化剂。面内MoN - MoS莫特-肖特基异质界面诱导电子重新分布和内建电场，有效激活惰性MoS基面，从而本质上提高电催化活性、改善电子导电性并增强水离解活性。此外，垂直的MoN - MoS纳米片为电化学反应提供了更多的活性位点，并促进了质量/电解质传输，而紧密耦合的HCNRs基底和金属MoN提供了快速的电子转移路径。因此，MoN - MoS /HCNRs电催化剂在酸性、中性和碱性电解质中，在10 mA cm的电流密度下，分别具有57、59和53 mV的超低过电位，塔菲尔斜率分别为38.4、43.5和37.9 mV dec，展现出优异的pH通用HER性能，优于已报道的基于MoS的催化剂，并且在整体水分解方面优于Pt。这项工作提出了一种在纳米尺度上构建面内异质界面的新策略，并为基于MoS的异质结构的HER电催化机制提供了新的见解。
