Corrosion Engineering towards NiFe‐Layered Double Hydroxide Macroporous Arrays with Enhanced Activity and Stability for Oxygen Evolution Reaction

Abstract

NiFe‐layered double hydroxide (NiFe‐LDH) is the benchmark catalyst for the oxygen evolution reaction (OER) in alkaline medium, however, it is still challenging to improve its activity and stability. Herein, NiFe‐LDH macroporous array electrodes are demonstrated to significantly enhance the activity and stability for oxygen evolution reaction. The electrodes are fabricated by the chemical and electrochemical corrosion process of Ni foam induced by ferric nitrate, hydrochloric acid and oxygen. By optimizing the amount of iron salt and acid and selecting the appropriate reaction temperature and time, the NiFe‐LDH electrodes only need the overpotential of 180 mV and 248 mV to reach the current density of 10 mA cm−2 and 500 mA cm−2, respectively, and remain highly stable for 1000 h at 500 mA cm−2. The unique macroporous array not only significantly increases the active area of NiFe‐LDH catalyst, but also creates a stable nanostructure that avoids severe reconstruction.

Enhancing Electrocatalytic Water Oxidation of NiFe-LDH Nanosheets via Bismuth-Induced Electronic Structure Engineering

“…Two accompanying satellite peaks of Ni 2p are located at 862.3 and 879.2 eV. Figure d displays two distinct peaks at 720.4 and 712.3 eV, which agree well with Fe 2p 1/2 and Fe 2p 3/2 . Four main peaks can be seen from the high resolution of the Bi 4f region (Figure e): two main peaks located at 158.3 and 163.4 eV can be identified as Bi 4f 7/2 and Bi 4f 5/2 signals of Bi 3+ .…”

“…Figure 3d displays two distinct peaks at 720.4 and 712.3 eV, which agree well with Fe 2p 1/2 and Fe 2p 3/2 . 48 Four main peaks can be seen from the high resolution of the Bi 4f region (Figure 3e): two main peaks located at 158.3 and 163.4 eV can be identified as Bi 4f 7/2 and Bi 4f 5/2 signals of Bi 3+ . Another two peaks located at 156.0 and 161.3 eV are attributed to Bi 4f 7/2 and Bi 4f 5/2 signals of Bi 0 in accordance with previous reports.…”

Enhancing the Hydrogen Evolution Reaction Performance of Solution-Corroded NiMo via Plasma Modification

“…To address this pertinent issue, it is necessary to develop facile, scalable methods in earth-abundant electrocatalyst synthesis to ensure that electrodes of various sizes can be fabricated in a cost-effective manner. One such promising approach is the solution-corrosion technique, done by corroding a metal substrate in a metal precursor solution at mild temperature conditions to create a desirable catalyst composition on the surface. − Metal hydroxides have been reportedly synthesized using this technique, delivering excellent OER performance on various substrate materials and sizes as (photo)­electrodes. ,, However, metal hydroxides are generally lacklustre in HER due to their inherent lack of HER active sites and overall low conductivity . In contrast, reduced metals and metal alloys such as Ni and NiMo are more HER-active, particularly in alkaline electrolytes …”

Combustion Growth of NiFe Layered Double Hydroxide for Efficient and Durable Oxygen Evolution Reaction

“…Furthermore, we provide an effective methanol-steam-driven strategy to directly fabricate NiFe LDH crystalline–amorphous (c–a) electrocatalysts on nickel foam or carbon cloth, which not only effectively promotes electrochemical activity but also enhances adhesion to support, conjuring up an ultra-active and ultrastable electrocatalyst . Recently, Song et al reported chemical and electrochemical corrosion engineering on Ni foam by ferric nitrate and hydrochloric acid in air, which generated NiFe LDH macroporous arrays with excellent activity and stability . Studies have shown that high-valence metals could improve OER performance, thanks to the readier oxidation transition of 3d metals .…”

“…12 Recently, Song et al reported chemical and electrochemical corrosion engineering on Ni foam by ferric nitrate and hydrochloric acid in air, which generated NiFe LDH macroporous arrays with excellent activity and stability. 13 Studies have shown that high-valence metals could improve OER performance, thanks to the readier oxidation transition of 3d metals. 14 An exciting method that could modulate metal valence is solution combustion synthesis, widely employed for nanoscale materials synthesis.…”