Structure and electrochemical property of amorphous molybdenum selenide H2-evolving catalysts prepared by a solvothermal synthesis. (21st May 2019)

• Record Type: Journal Article
• Authors: Nguyen, Chuc T.; Duong, Tuan M.; Nguyen, Mai; Nguyen, Quyen T.; Nguyen, Anh D.; Dieu Thuy, Ung Thi; Truong, Quang Duc; Nguyen, Tung T.; Nguyen, Quang Liem; Tran, Phong D.
• Is Part Of: International journal of hydrogen energy. Volume 44:Number 26(2019)
• Page Start: 13273
• Page End: 13283
• Publication Date: 2019-05-21
• Subjects: Chalcogenide -- Molybdenum selenide -- Catalysis -- Water electrolysis -- Hydrogen; Hydrogen as fuel -- Periodicals; Hydrogène (Combustible) -- Périodiques; Hydrogen as fuel; Periodicals; 665.81
• DOI: 10.1016/j.ijhydene.2019.03.186
• Languages: English
• ISSNs: 0360-3199

Abstract

Abstract: Amorphous molybdenum selenide nanoparticles were synthesized by the solvothermal treatment of Mo(CO)6 and Se in dimethylformamide. By varying the Mo(CO)6 over Se molar ratio, we obtained a family of MoSe nanoparticles having comparable morphology but different chemical composition. Using a combination of experimental analyses ( e.g. XRD, ICP-MS, Raman, XPS) and DFT theoretical calculation, we found that the structure of MoSe was close to that of the amorphous molybdenum sulfide analogous but not that of MoSe2 layers. The MoSe was found to consist of [Mo3 Se13 ] 2- cluster within its structure together with some structural defects. Thanks to its less ordered structure, the MoSe can be activated by several chemical and electrochemical treatment resulting in a catalytic enhancement. A treatment with fuming HCl resulted in generation of a novel catalyst displaying 1.4 time higher catalytic current. Remarkably, a treatment with reflux NaOH solution resulted in generation of a component being soluble in water and displaying catalytic H2 -evolving activity at a moderate onset overpotential of ca. 200 mV, being one of the most attractives homogeneous catalysts in water. Graphical abstract: Image 1 Highlights: Amorphous MoSe is constituted of [Mo3 Se13 ] 2- building block and Mo-vacant defects. Composition and catalytic activity of MoSe depends on the Mo:Se precursor ratio. Chemical treatment with HCl or electrochemical treatment enhances MoSe activity. MoSe treatment with NaOH generates the [Mo1.1 Se] as excellent homogeneous catalyst. Origin of pre-peak reduction is studied by chemical and electrochemical analyses.