Premium
Self‐Assembly of Large‐Area 2D Polycrystalline Transition Metal Carbides for Hydrogen Electrocatalysis
Author(s) -
Zang Xining,
Chen Wenshu,
Zou Xiaolong,
Hohman J. Nathan,
Yang Lujie,
Li Buxuan,
Wei Minsong,
Zhu Chenhui,
Liang Jiaming,
Sanghadasa Mohan,
Gu Jiajun,
Lin Liwei
Publication year - 2018
Publication title -
advanced materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 10.707
H-Index - 527
eISSN - 1521-4095
pISSN - 0935-9648
DOI - 10.1002/adma.201805188
Subject(s) - tafel equation , materials science , electrocatalyst , overpotential , transition metal , nanotechnology , chemical engineering , carbide , catalysis , metal , carbonization , electrochemistry , composite material , electrode , metallurgy , scanning electron microscope , organic chemistry , chemistry , engineering
Low‐dimensional (0/1/2 dimension) transition metal carbides (TMCs) possess intriguing electrical, mechanical, and electrochemical properties, and they serve as convenient supports for transition metal catalysts. Large‐area single‐crystalline 2D TMC sheets are generally prepared by exfoliating MXene sheets from MAX phases. Here, a versatile bottom‐up method is reported for preparing ultrathin TMC sheets (≈10 nm in thickness and >100 μm in lateral size) with metal nanoparticle decoration. A gelatin hydrogel is employed as a scaffold to coordinate metal ions (Mo 5+ , W 6+ , Co 2+ ), resulting in ultrathin‐film morphologies of diverse TMC sheets. Carbonization of the scaffold at 600 °C presents a facile route to the corresponding MoC x , WC x , CoC x , and to metal‐rich hybrids (Mo 2− x W x C and W/Mo 2 C–Co). Among these materials, the Mo 2 C–Co hybrid provides excellent hydrogen evolution reaction (HER) efficiency (Tafel slope of 39 mV dec −1 and 48 mVj = 10 mA cm‐2 in overpotential in 0.5 m H 2 SO 4 ). Such performance makes Mo 2 C–Co a viable noble‐metal‐free catalyst for the HER, and is competitive with the standard platinum on carbon support. This template‐assisted, self‐assembling, scalable, and low‐cost manufacturing process presents a new tactic to construct low‐dimensional TMCs with applications in various clean‐energy‐related fields.