Fe‐CoP Electrocatalyst Derived from a Bimetallic Prussian Blue Analogue for Large‐Current‐Density Oxygen Evolution and Overall Water Splitting

• Published in: Advanced science Vol. 5; no. 10; pp. 1800949 - n/a
• Main Authors: Cao, Li‐Ming, Hu, Yu‐Wen, Tang, Shang‐Feng, Iljin, Andrey, Wang, Jia‐Wei, Zhang, Zhi‐Ming, Lu, Tong‐Bu
• Format: Journal Article
• Language: English
• Published: Germany John Wiley and Sons Inc 01-10-2018
• Subjects: bifunctional electrocatalysts; large current density; oxygen evolution; Prussian blue analogues; Prussian blue analogues; large current density; bifunctional electrocatalysts; oxygen evolution
• ISSN: 2198-3844; 2198-3844
• DOI: 10.1002/advs.201800949

Industrial application of overall water splitting requires developing readily available, highly efficient, and stable oxygen evolution electrocatalysts that can efficiently drive large current density. This study reports a facile and practical method to fabricate a non‐noble metal catalyst by directly growing a Co‐Fe Prussian blue analogue on a 3D porous conductive substrate, which is further phosphorized into a bifunctional Fe‐doped CoP (Fe‐CoP) electrocatalyst. The Fe‐CoP/NF (nickel foam) catalyst shows efficient electrocatalytic activity for oxygen evolution reaction, requiring low overpotentials of 190, 295, and 428 mV to achieve 10, 500, and 1000 mA cm−2 current densities in 1.0 m KOH solution. In addition, the Fe‐CoP/NF can also function as a highly active electrocatalyst for hydrogen evolution reaction with a low overpotential of 78 mV at 10 mA cm−2 current density in alkaline solution. Thus, the Fe‐CoP/NF electrode with meso/macropores can act as both an anode and a cathode to fabricate an electrolyzer for overall water splitting, only requiring a cell voltage of 1.49 V to afford a 10 mA cm−2 current density with remarkable stability. This performance appears to be among the best reported values and is much better than that of the IrO2‐Pt/C‐based electrolyzer.
A gentle and practical pathway is reported to fabricate efficient, non‐noble metal catalyst by directly growing a bimetallic prussian blue analogue 3D conductive substrate, phosphorized into a 3D bifunctional hierarchical‐pore Fe‐CoP electrocatalyst. The as‐obtained Fe‐CoP can drive large‐current‐density oxygen evolution and efficiently catalyze overall water splitting.