Dual‐Native Vacancy Activated Basal Plane and Conductivity of MoSe2 with High‐Efficiency Hydrogen Evolution Reaction

• Published in: Small (Weinheim an der Bergstrasse, Germany) Vol. 14; no. 14; pp. e1704150 - n/a
• Main Authors: Gao, Daqiang, Xia, Baorui, Wang, Yanyan, Xiao, Wen, Xi, Pinxian, Xue, Desheng, Ding, Jun
• Format: Journal Article
• Language: English
• Published: Weinheim Wiley Subscription Services, Inc 05.04.2018
• Subjects: Basal plane; Catalysis; Chalcogenides; Crystals; CVD; dual vacancies; Electrocatalysts; first‐principles calculations; Free energy; HER; Hydrogen evolution reactions; Hydrogen-based energy; MoSe2; Nanotechnology; Vacancies
• ISSN: 1613-6810; 1613-6829
• DOI: 10.1002/smll.201704150

Although transition metal dichalcogenide MoSe2 is recognized as one of the low‐cost and efficient electrocatalysts for the hydrogen evolution reaction (HER), its thermodynamically stable basal plane and semiconducting property still hamper the electrocatalytic activity. Here, it is demonstrated that the basal plane and edges of 2H‐MoSe2 toward HER can be activated by introducing dual‐native vacancy. The first‐principle calculations indicate that both the Se and Mo vacancies together activate the electrocatalytic sites in the basal plane and edges of MoSe2 with the optimal hydrogen adsorption free energy (ΔGH*) of 0 eV. Experimentally, 2D MoSe2 nanosheet arrays with a large amount of dual‐native vacancies are fabricated as a catalytic working electrode, which possesses an overpotential of 126 mV at a current density of 100 mV cm−2, a Tafel slope of 38 mV dec−1, and an excellent long‐term durability. The findings pave a rational pathway to trigger the activity of inert MoSe2 toward HER and also can be extended to other layered dichalcogenide. Dual‐native‐vacancy (Mo and Se vacancies) in MoSe2 nanosheets are proved through experimental and first‐principles study. Herein, dual‐native‐vacancy can activate the hydrogen evolution reaction (HER) activity of both basal plane and edges in MoSe2, guaranteeing its efficient HER catalysis. Meanwhile, dual‐native‐vacancy in the MoSe2 can enhance the conductivity of MoSe2 basal plane to promote rapid charge transfer over catalytic electrode.