Highly active and stable electrocatalytic transition metal phosphides (Ni2P and FeP) nanoparticles on porous carbon cloth for overall water splitting at high current density

• Published in: International journal of energy research Vol. 44; no. 14; pp. 11894 - 11907
• Main Authors: Shin, Hyun Jung, Park, Sung‐Woo, Kim, Dong‐Wan
• Format: Journal Article
• Language: English
• Published: Chichester, UK John Wiley & Sons, Inc 01-11-2020; Hindawi Limited
• Subjects: Carbon; Cathodes; Cloth; Current density; Durability; Electrodes; Heavy metals; High current; Hydrogen evolution reactions; Hydrogen production; Immersion coating; Iron; Nanoparticles; Nickel; Phase transitions; Phosphides; porous carbon cloth; self‐supporting electrodes; Splitting; Substrates; Temperature effects; Toughness; transition metal phosphides; Transition metals; Water splitting
• ISSN: 0363-907X; 1099-114X
• DOI: 10.1002/er.5833

Summary
Highly active and stable hydrogen production at high current densities is required for practical application of electrocatalytic water splitting. In this study, highly active self‐supporting electrodes with excellent durability were designed and developed for high‐performance overall water splitting at a high current density. First, a colloid‐based dip‐coating method using porous carbon cloth (PCC) was introduced to obtain uniformly coated Ni and Fe nanoparticles on a conductive substrate. Then, the desired phase transitions of Ni and Fe to Ni2P and FeP, respectively, proceeded by thermal phosphidation at optimum temperature. The uniformly interconnected Ni2P layers on the PCC substrate (Ni2P@PCC) and FeP layers on the PCC substrate (FeP@PCC) exhibited outstanding oxygen and hydrogen evolution reactions, respectively. When each electrode was adopted as an anode and a cathode for the overall water splitting cell, excellent performance was achieved, with a low operational voltage of 1.76 V and high durability for 100 hours at a high current density of 50 mA cm−2.
We designed and developed uniformly interconnected transition metal phosphides nanoparticles on porous carbon cloth as highly efficient and stable self‐supporting electrodes for the overall water splitting at high current density. When configurate overall water splitting cell consisted of Ni2P@PCC for anode and FeP@PCC for cathode, lower operational voltage of 1.76 V than noble‐metal based overall water splitting cell (RuO2@PCC//Pt@C@PCC) of 1.85 V could be achieved at high current density of 50 mA cm−2.