title: Nickel-Cobalt Diselenide 3D Mesoporous Nanosheet Networks Supported on Ni Foam: An All-pH Highly Efficient Integrated Electrocatalyst for Hydrogen Evolution.
abstract: Novel 3D Ni1-xCoxSe2mesoporous nanosheet networks with tunable stoichiometry are successfully synthesized on Ni foam (Ni1-xCoxSe2MNSN/NF with x ranging from 0 to 0.35). The collective effects of special morphological design and electronic structure engineering enable the integrated electrocatalyst to have very high activity for hydrogen evolution reaction (HER) and excellent stability in a wide pH range. Ni0.89Co0.11Se2MNSN/NF is revealed to exhibit an overpotential (η10) of 85 mV at -10 mA cm-2in alkaline medium (pH 14) and η10of 52 mV in acidic solution (pH 0), which are the best among all selenide-based electrocatalysts reported thus far. In particular, it is shown for the first time that the catalyst can work efficiently in neutral solution (pH 7) with a record η10of 82 mV for all noble metal-free electrocatalysts ever reported. Based on theoretical calculations, it is further verified that the advanced all-pH HER activity of Ni0.89Co0.11Se2is originated from the enhanced adsorption of both H+and H2O induced by the substitutional doping of cobalt at an optimal level. It is believed that the present work provides a valuable route for the design and synthesis of inexpensive and efficient all-pH HER electrocatalysts.
authors.affiliation: Center of Super-Diamond and Advanced Films (COSDAF), Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong, China.
authors.forename: Bin
authors.initials: B
authors.lastname: Liu
authors.affiliation: Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing, 100190, China.
authors.forename: Yu-Fei
authors.initials: YF
authors.lastname: Zhao
authors.affiliation: Department of Chemistry, Institute for Advanced Study, Institute of Molecular Functional Materials and Division of Biomedical Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China.
authors.forename: Hui-Qing
authors.initials: HQ
authors.lastname: Peng
authors.affiliation: Center of Super-Diamond and Advanced Films (COSDAF), Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong, China.
authors.forename: Zhen-Yu
authors.initials: ZY
authors.lastname: Zhang
authors.affiliation: Center of Super-Diamond and Advanced Films (COSDAF), Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong, China.
authors.forename: Chun-Kit
authors.initials: CK
authors.lastname: Sit
authors.affiliation: Center of Super-Diamond and Advanced Films (COSDAF), Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong, China.
authors.forename: Muk-Fung
authors.initials: MF
authors.lastname: Yuen
authors.affiliation: Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing, 100190, China.
authors.forename: Tie-Rui
authors.initials: TR
authors.lastname: Zhang
authors.affiliation: Center of Super-Diamond and Advanced Films (COSDAF), Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong, China.
authors.forename: Chun-Sing
authors.initials: CS
authors.lastname: Lee
authors.affiliation: Center of Super-Diamond and Advanced Films (COSDAF), Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong, China.
authors.forename: Wen-Jun
authors.initials: WJ
authors.lastname: Zhang
keywords: all-pH electrolysis; electrocatalysts; electronic structure regulation; hydrogen evolution; nickel-cobalt diselenide