An Intriguing Pea‐Like Nanostructure of Cobalt Phosphide on Molybdenum Carbide Incorporated Nitrogen‐Doped Carbon Nanosheets for Efficient Electrochemical Water Splitting

• DOI: 10.1002/cssc.201801810
• Publication Date: 2018-09-20T04:11:46Z
• Authors: Soumen Dutta; Arindam Indra; HyukSu Han; Taeseup Song
• Keywords: 7. Clean energy; 01 natural sciences; 0104 chemical sciences

AbstractThe development of noble‐metal‐free, efficient, electrochemical, water‐splitting catalyst systems has attracted considerable attention in recent times. In this study, a metal–organic framework based synthetic route to couple two non‐noble‐metal‐based catalysts, CoP and Mo2C, supported on nitrogen‐doped carbon has been developed. The strategy enables the formation of a nanohybrid with an attractive pea‐like morphology, in which spherical CoP particles (≈10 nm) are embedded on two‐dimensional nitrogen‐doped carbon enriched with ultrafine Mo2C nanoparticles. This composition boosts the electrochemical alkaline water‐splitting reaction by showing overpotentials (η10) of only 94 and 265 mV for the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), respectively, at a current density of 10 mA cm−2. Additionally, in an acidic medium, the η10 values are 107 and 330 mV for HER and OER, respectively; this suggests good bifunctionality at both lower and higher pH levels. Overall water splitting has been demonstrated by the developed catalyst at a cell voltage of 1.64 V for a current density of 10 mA cm−2 in alkaline medium, and a constant current is produced for more than 40 h under chronoamperometric conditions. This study describes the combination of two nanocomponents, with interconnected surface structures, which result in highly active and stable electrocatalytic performance.