title: Ultrafine Molybdenum Carbide Nanoparticles Composited with Carbon as a Highly Active Hydrogen-Evolution Electrocatalyst.
abstract: The replacement of platinum with non-precious-metal electrocatalysts with high efficiency and superior stability for the hydrogen-evolution reaction (HER) remains a great challenge. Herein, we report the one-step synthesis of uniform, ultrafine molybdenum carbide (Mo2C) nanoparticles (NPs) within a carbon matrix from inexpensive starting materials (dicyanamide and ammonium molybdate). The optimized catalyst consisting of Mo2C NPs with sizes lower than 3 nm encapsulated by ultrathin graphene shells (ca. 1-3 layers) showed superior HER activity in acidic media, with a very low onset potential of -6 mV, a small Tafel slope of 41 mV dec(-1), and a large exchange current density of 0.179 mA cm(-2), as well as good stability during operation for 12 h. These excellent properties are similar to those of state-of-the-art 20% Pt/C and make the catalyst one of the most active acid-stable electrocatalysts ever reported for HER.
authors.affiliation: State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, 1295 Dingxi Road, Shanghai 200050 (P. R. China).|Innovation Center for Inorganic Materials Genomic Science, Shanghai Institute of Ceramics, Shanghai 200050 (P. R. China).|Shanghai Materials Genome Institute, Shanghai 200444 (P. R. China).
authors.forename: Ruguang
authors.initials: R
authors.lastname: Ma
authors.affiliation: State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, 1295 Dingxi Road, Shanghai 200050 (P. R. China).|Innovation Center for Inorganic Materials Genomic Science, Shanghai Institute of Ceramics, Shanghai 200050 (P. R. China).|Shanghai Materials Genome Institute, Shanghai 200444 (P. R. China).
authors.forename: Yao
authors.initials: Y
authors.lastname: Zhou
authors.affiliation: State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, 1295 Dingxi Road, Shanghai 200050 (P. R. China).|University of the Chinese Academy of Sciences, Beijing 100049 (P. R. China).
authors.forename: Yongfang
authors.initials: Y
authors.lastname: Chen
authors.affiliation: State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, 1295 Dingxi Road, Shanghai 200050 (P. R. China).
authors.forename: Pengxi
authors.initials: P
authors.lastname: Li
authors.affiliation: State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, 1295 Dingxi Road, Shanghai 200050 (P. R. China).|Innovation Center for Inorganic Materials Genomic Science, Shanghai Institute of Ceramics, Shanghai 200050 (P. R. China).|Shanghai Materials Genome Institute, Shanghai 200444 (P. R. China).
authors.forename: Qian
authors.initials: Q
authors.lastname: Liu
authors.affiliation: State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, 1295 Dingxi Road, Shanghai 200050 (P. R. China). jiacheng.wang@mail.sic.ac.cn.|Innovation Center for Inorganic Materials Genomic Science, Shanghai Institute of Ceramics, Shanghai 200050 (P. R. China). jiacheng.wang@mail.sic.ac.cn.|Shanghai Materials Genome Institute, Shanghai 200444 (P. R. China). jiacheng.wang@mail.sic.ac.cn.
authors.forename: Jiacheng
authors.initials: J
authors.lastname: Wang
keywords: electrocatalysis; graphene; hydrogen-evolution reaction; molybdenum carbide nanoparticles; water splitting