Three-Dimensional Smart Catalyst Electrode for Oxygen Evolution Reaction

• Published in: Advanced energy materials Vol. 5; no. 18; pp. np - n/a
• Main Authors: Chen, Sheng, Duan, Jingjing, Bian, Pengju, Tang, Youhong, Zheng, Rongkun, Qiao, Shi-Zhang
• Format: Journal Article
• Language: English
• Published: Weinheim Blackwell Publishing Ltd 01-09-2015; Wiley Subscription Services, Inc
• Subjects: Bleaching; Catalysis; catalyst electrodes; Catalysts; Electrodes; Evolution; heteroatom doping; Monitors; Nanostructure; Oxygen; oxygen evolution reaction; smart material; Three dimensional; Two-dimensional nanolayers
• ISSN: 1614-6832; 1614-6840
• DOI: 10.1002/aenm.201500936

A multifunctional catalyst electrode mimicking external stimuli–responsive property has been prepared by the in situ growth of nitrogen (N)‐doped NiFe double layered hydroxide (N–NiFe LDH) nanolayers on a 3D nickel foam substrate framework. The electrode demonstrates superior performance toward catalyzing oxygen evolution reaction (OER), affording a low overpotential of 0.23 V at the current density of 10 mA cm−2, high Faradaic efficiency of ≈98%, and stable operation for >60 h. Meanwhile, the electrode can dynamically change its color from gray silver to dark black with the OER happening, and the coloration/bleaching processes persist for at least 5000 cycles, rendering it a useful tool to monitor the catalytic process. Mechanism study reveals that the excellent structural properties of electrode such as 3D conductive framework, ultra thickness of N–NiFe LDH nanolayer (≈0.8 nm), and high N‐doping content (≈17.8%) make significant contribution to achieving enhanced catalytic performance, while N–NiFe LDH nanolayer on electrode is the main contributor to the stimuli‐responsive property with the reversible extraction/insertion of electrons from/into N–NiFe LDH leading to the coloration/bleaching processes. Potential application of this electrode has been further demonstrated by integrating it into a Zn–air battery device to identify the charging process during electrochemical cycling.
A 3D catalyst electrode mimicking external stimuli–responsive functionality is fabricated. It exhibits superior performance toward catalyzing oxygen evolution reaction (OER) and dynamically changes its color with the OER, providing an opportunity to quickly monitor the catalytic reaction.