Stringing Bimetallic Metal–Organic Framework‐Derived Cobalt Phosphide Composite for High‐Efficiency Overall Water Splitting

• Published in: Advanced science Vol. 7; no. 5; pp. 1903195 - n/a
• Main Authors: Chai, Lulu, Hu, Zhuoyi, Wang, Xian, Xu, Yuwei, Zhang, Linjie, Li, Ting‐Ting, Hu, Yue, Qian, Jinjie, Huang, Shaoming
• Format: Journal Article
• Language: English
• Published: Germany John Wiley & Sons, Inc 01.03.2020; John Wiley and Sons Inc; Wiley
• Subjects: Atoms & subatomic particles; Carbon; Cobalt; cobalt phosphide; Fourier transforms; Ligands; metal–organic frameworks; Morphology; Nanoparticles; nitrogen‐doped carbon nanotubes; overall water splitting; Spectrum analysis; cobalt phosphide; metal–organic frameworks; overall water splitting; nitrogen‐doped carbon nanotubes
• ISSN: 2198-3844; 2198-3844
• DOI: 10.1002/advs.201903195

Water electrolysis is an emerging energy conversion technology, which is significant for efficient hydrogen (H2) production. Based on the high‐activity transition metal ions and metal alloys of ultrastable bifunctional catalyst, the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) are the key to achieving the energy conversion method by overall water splitting (OWS). This study reports that the Co‐based coordination polymer (ZIF‐67) anchoring on an indium–organic framework (InOF‐1) composite (InOF‐1@ZIF‐67) is treated followed by carbonization and phosphorization to successfully obtain CoP nanoparticles–embedded carbon nanotubes and nitrogen‐doped carbon materials (CoP‐InNC@CNT). As HER and OER electrocatalysts, it is demonstrated that CoP‐InNC@CNT simultaneously exhibit high HER performance (overpotential of 153 mV in 0.5 m H2SO4 and 159 mV in 1.0 m KOH) and OER performance (overpotential of 270 mV in 1.0 m KOH) activities to reach the current density of 10 mA cm−2. In addition, these CoP‐InNC@CNT rods, as a cathode and an anode, can display an excellent OWS performance with η10 = 1.58 V and better stability, which shows the satisfying electrocatalyst for the OWS compared to control materials. This method ensures the tight and uniform growth of the fast nucleating and stable materials on substrate and can be further applied for practical electrochemical reactions. A type of CoP embedded in carbon nanotubes and nitrogen‐doped carbon material calcined from a bimetallic metal–organic frameworks (MOF) precursor is designed and prepared by growing Co‐based MOFs on an indium–organic framework. The CoP incorporation can greatly promote the water splitting kinetics by the optimized catalyst of CoP‐InNC@CNT, thus the high electrocatalytic activity is achieved toward both the hydrogen evolution reaction and oxygen evolution reaction.