@article{33cdbc4ddc72495a90c6bbd965d78d90,
title = "Surface electron accumulation and enhanced hydrogen evolution reaction in MoSe2 basal planes",
abstract = "The spontaneous formation of surface electron accumulation (SEA) was observed in synthesized molybdenum diselenide (MoSe2) layered crystals with two-hexagonal (2 H) structure. An anomalously high electron concentration at the surface up to 1019 cm−3 is several orders of magnitude higher than that (3.6 × 1012 cm−3) of the inner bulk. The SEA is found to be generated easily by mechanical exfoliation and room temperature deselenization. Se-vacancies have been confirmed to be the major source resulting in SEA and n-type conductivity, and also the active sites for electrochemical catalysis in MoSe2. Noted that the SEA conjugated with the Se-vacancy-related surface defects enhances the electrochemical hydrogen evolution reaction (HER) activity substantially. The optimized HER efficiency with an overpotential at 0.17 V and Tafel slope at 60 mV/dec of the basal plane of 2 H-MoSe2 was achieved by the nitrogen plasma treatment, which has outperformed several nanostructures, thin films, and hybrid counterparts. This study reveals the intriguing surface-dominant electronic property and its effect on the HER enhancement of the basal plane, which is crucial for development of a stable, low-cost and highly efficient catalyst using 2 H-MoSe2.",
keywords = "Angle-resolved photoemission spectroscopy, Hydrogen evolution reaction, Molybdenum diselenide, Scanning tunneling microscopy, Selenium vacancy, Surface electron accumulation",
author = "Chang, {Y. S.} and Chen, {C. Y.} and Ho, {C. J.} and Cheng, {C. M.} and Chen, {H. R.} and Fu, {T. Y.} and Huang, {Y. T.} and Ke, {S. W.} and Du, {H. Y.} and Lee, {K. Y.} and Chao, {L. C.} and Chen, {L. C.} and Chen, {K. H.} and Chu, {Y. W.} and Chen, {R. S.}",
note = "Funding Information: This paper is in memory of Prof. Y. S. Huang at Taiwan Tech for his support of the MoSe 2 single crystals. RSC, CMC, and TYF thank the support of the Ministry of Science and Technology ( MOST ), Taiwan under the projects MOST 108-2628-M-011-001-MY3 , 105-2112-M-011-001-MY3 , 104-2923-M-011-001-MY3 , 105-2112-M-213-006-MY2 , 107-2112-M-213–001-MY3 , and 105-2112-M-003-014 . HYD, LCC and KHC thank the financial supports under the Science Vanguard Research Project (MOST 108-2119-M-002-030 and 109-2123-M-002-004 ), the Center of Atomic Initiative for New Materials (AI-Mat), National Taiwan University ( 108L9008 and 109L9008 ) and the Deep Decarbonization Project, Academia Sinica ( AS-SS-106-02-3 and AS-iMATE-108-31 ). Publisher Copyright: {\textcopyright} 2021 Elsevier Ltd",
year = "2021",
month = jun,
doi = "10.1016/j.nanoen.2021.105922",
language = "English",
volume = "84",
journal = "Nano Energy",
issn = "2211-2855",
publisher = "Elsevier BV",
}
