Vertically mounting molybdenum disulfide nanosheets on dimolybdenum carbide nanomeshes enables efficient hydrogen evolution

• Published in: Nano research Vol. 15; no. 5; pp. 3946 - 3951
• Main Authors: Wang, Tingting, Wang, Pengyan, Pang, Yajun, Wu, Yitian, Yang, Jin, Chen, Hao, Gao, Xiaorui, Mu, Shichun, Kou, Zongkui
• Format: Journal Article
• Language: English
• Published: Beijing Tsinghua University Press 01.05.2022; Springer Nature B.V
• Subjects: Adsorption; Atomic/Molecular Structure and Spectra; Biomedicine; Biotechnology; Catalysis; Catalysts; Chemistry and Materials Science; Condensed Matter Physics; Cycle ratio; Free energy; Heterostructures; Hydrogen; Hydrogen evolution reactions; Kinetics; Materials Science; Molybdenum; Molybdenum carbide; Molybdenum disulfide; Nanosheets; Nanotechnology; Research Article; transition metal disulfide; transition metal carbide; hydrogen adsorption/desorption; hydrogen evolution reaction; two-dimensional nonlayered/layered heterostructure
• ISSN: 1998-0124; 1998-0000
• DOI: 10.1007/s12274-022-4072-5

Designing hierarchical heterostructure to optimize the adsorption of hydrogen intermediate (H*) is impressive for hydrogen evolution reaction (HER) catalysis. Herein, we show that vertically mounting two-dimensional (2D) layered molybdenum disulfide (MoS 2 ) nanosheets on 2D nonlayered dimolybdenum carbide (Mo 2 C) nanomeshes to form a hierarchical heterostructure largely accelerates the HER kinetics in acidic electrolyte due to the weakening adsorption strength of H* on 2D Mo 2 C nanomeshes. Our hierarchical MoS 2 /Mo 2 C heterostructure therefore gives a decrease of overpotential for up to 500 mV at −10 mA·cm −2 and an almost 200-fold higher kinetics current density compared with the pristine Mo 2 C nanomeshes and maintains robust stability with a small drop of overpotential for only 16 mV upon 5,000 cycles. We further rationalize this finding by theoretical calculations and find an optimized adsorption free energy of H*, identifying that the MoS 2 featuring strong H* desorption plays a key role in weakening the strong binding of Mo 2 C with H* and therefore improves the intrinsic HER activity on active C sites of Mo 2 C. This present finding shines the light on the rational design of heterostructured catalysts with synergistic geometry.