title: Ultrasmall and phase-pure W2C nanoparticles for efficient electrocatalytic and photoelectrochemical hydrogen evolution.
abstract: Earlier research has been primarily focused on WC as one of the most promising earth-abundant electrocatalysts for hydrogen evolution reaction (HER), whereas the other compound in this carbide family-W2C-has received far less attention. Our theoretical calculations suggest that such a focus is misplaced and W2C is potentially more HER-active than WC. Nevertheless, the preparation of phase pure and sintering-free W2C nanostructures represents a formidable challenge. Here we develop an improved carburization method and successfully prepare ultrasmall and phase-pure W2C nanoparticles. When evaluated for HER electrocatalysis, W2C nanoparticles exhibit a small onset overpotential of 50 mV, a Tafel slope of 45 mV dec-1and outstanding long-term cycling stability, which are dramatically improved over all existing WC-based materials. In addition, the integration of W2C nanoparticles with p-type Si nanowires enables highly active and sustainable solar-driven hydrogen production. Our results highlight the great potential of this traditionally non-popular material in HER electrocatalysis.
authors.affiliation: Institute of Functional Nano &Soft Materials (FUNSOM), Jiangsu Key Laboratory for Carbon-Based Functional Materials and Devices, Soochow University, Suzhou 215123, China.
authors.forename: Qiufang
authors.initials: Q
authors.lastname: Gong
authors.affiliation: College of Chemistry and Materials Science, Nanjing Normal University, Nanjing 210023, China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Silicon Materials, School of Materials Science and Engineering, Zhejiang University, Hangzhou, Zhejiang 310027, China.
authors.forename: Qi
authors.identifier: 0000-0002-9928-1257
authors.initials: Q
authors.lastname: Hu
authors.affiliation: Canadian Light Source Inc., Saskatoon, Saskatchewan, Canada S7N 0X4.
authors.forename: Jigang
authors.initials: J
authors.lastname: Zhou
authors.affiliation: Canadian Light Source Inc., Saskatoon, Saskatchewan, Canada S7N 0X4.
authors.forename: Renfei
authors.initials: R
authors.lastname: Feng
authors.affiliation: Department of Chemistry, Dalhousie University, Halifax, Canada NS B3H 4R2.
authors.forename: Paul N
authors.initials: PN
authors.lastname: Duchesne
authors.affiliation: Department of Chemistry, Dalhousie University, Halifax, Canada NS B3H 4R2.
authors.forename: Peng
authors.identifier: 0000-0003-3603-0175
authors.initials: P
authors.lastname: Zhang
authors.affiliation: Institute of Functional Nano &Soft Materials (FUNSOM), Jiangsu Key Laboratory for Carbon-Based Functional Materials and Devices, Soochow University, Suzhou 215123, China.
authors.forename: Fengjiao
authors.initials: F
authors.lastname: Chen
authors.affiliation: Institute of Functional Nano &Soft Materials (FUNSOM), Jiangsu Key Laboratory for Carbon-Based Functional Materials and Devices, Soochow University, Suzhou 215123, China.
authors.forename: Na
authors.initials: N
authors.lastname: Han
authors.affiliation: College of Chemistry and Materials Science, Nanjing Normal University, Nanjing 210023, China.
authors.forename: Yafei
authors.initials: Y
authors.lastname: Li
authors.affiliation: State Key Laboratory of Silicon Materials, School of Materials Science and Engineering, Zhejiang University, Hangzhou, Zhejiang 310027, China.
authors.forename: Chuanhong
authors.initials: C
authors.lastname: Jin
authors.affiliation: Institute of Functional Nano &Soft Materials (FUNSOM), Jiangsu Key Laboratory for Carbon-Based Functional Materials and Devices, Soochow University, Suzhou 215123, China.
authors.forename: Yanguang
authors.initials: Y
authors.lastname: Li
authors.affiliation: Institute of Functional Nano &Soft Materials (FUNSOM), Jiangsu Key Laboratory for Carbon-Based Functional Materials and Devices, Soochow University, Suzhou 215123, China.
authors.forename: Shuit-Tong
authors.initials: ST
authors.lastname: Lee