Co(OH)₂ Nanoparticle‐Encapsulating Conductive Nanowires Array: Room‐Temperature Electrochemical Preparation for High‐Performance Water Oxidation Electrocatalysis

Abstract

It is highly desired but still remains challenging to design and develop a Co-based nanoparticle-encapsulated conductive nanoarray at room temperature for high-performance water oxidation electrocatalysis. Here, it is reported that room-temperature anodization of a Co(TCNQ) (TCNQ = tetracyanoquinodimethane) nanowire array on copper foam at alkaline pH leads to in situ electrochemcial oxidation of TCNQ into water-insoluable TCNQ nanoarray embedding Co(OH) nanoparticles. Such Co(OH) -TCNQ/CF shows superior catalytic activity for water oxidation and demands only a low overpotential of 276 mV to drive a geometrical current density of 25 mA cm in 1.0 m KOH. Notably, it also demonstrates strong long-term electrochemical durability with its activity being retrained for at least 25 h, a high turnover frequency of 0.97 s at an overpotential of 450 mV and 100% Faradic efficiency. This study provides an exciting new method for the rational design and development of a conductive TCNQ-based nanoarray as an interesting 3D material for advanced electrochemical applications.

Iron–Salen Complex and Co2+ Ion‐Derived Cobalt–Iron Hydroxide/Carbon Nanohybrid as an Efficient Oxygen Evolution Electrocatalyst

“…The surface molar ratio of Co/Fe in sample was 1.21:1 based on the XPS measurement, which is consistent with the result of ICP analysis. [37,38] A prominent peak of 531.3 eV in the O 1s spectrum (Figure 2c) agrees with metal hydroxides as the dominant active species. [32,36,37] The Co 2p spectrum in Figure 2b can be deconvoluted into two spin-orbit peaks at the binding energies of 781.2 (Co 2p 3/2 ) and 796.8 eV (Co 2p 1/2 ), and the corresponding satellite peaks at 786.1 and 803.1 eV are consistent with the presence of Co 2+ .…”

Molecular Engineering of a 3D Self‐Supported Electrode for Oxygen Electrocatalysis in Neutral Media

“…Co corrole 1 is active and robust to catalyze OER and ORR . The 3D self‐supported Fe 3 O 4 NR/TM has advantages to offer large electrochemical surface area and to ensure rapid charge transfer and mass diffusion . Fe 3 O 4 is chosen because it is conductive and it alone has poor OER and ORR activities at neutral pH.…”

“…[29][30][31][32][33][34] The3 Ds elf-supported Fe 3 O 4 NR/TM has advantages to offer large electrochemical surface area and to ensure rapid charge transfer and mass diffusion. [10,11,[35][36][37][38] Fe 3 O 4 is chosen because it is conductive and it alone has poor OER and ORR activities at neutral pH. This intestinal-villi-like electrode displays apparent performance comparable to material-based electrodes for OER and ORR at neutral pH, and more importantly has much higher atom efficiency as evidenced by at least two magnitudes higher turnover frequency (TOF).Asapractical demonstration, we applied this electrode in Zn-air battery operating in neutral media, and achieved small charge-discharge voltage gap of 1.19 V, large peak power density of 90.4 mW cm À2 ,a nd high rechargeable stability for > 100 h. This work is the first example of molecular electrocatalysis employed in metal-air batteries and demonstrates promising applications of molecule-engineered electrodes in energy conversion and storage.…”

Interface Electronic Coupling in Hierarchical FeLDH(FeCo)/Co(OH)2 Arrays for Efficient Electrocatalytic Oxygen Evolution

“…An attractive strategy is obtaining thin 2D‐TMHs in situ from metal–organic frameworks (MOFs). The resulting materials often exhibit high catalytic activity attributed to their abundant edges/defects or coordinatively unsaturated metal sites . Unfortunately, the catalytic durability of the thus‐prepared 2D‐TMHs cannot be maintained.…”

“…The resulting materials often exhibit high catalytic activity attributed to their abundant edges/defectso rc oordinatively unsaturated metal sites. [5,[26][27][28] Unfortunately,t he catalytic durability of the thusprepared 2D-TMHs cannot be maintained. To solve this problem, studies are devoted to constructing bi-or multimetallic hydroxides [15,20,[29][30][31] by partially replacingt he originalc ations in the crystal lattice by heterogeneous cations, which leads to speciali nteractionsa mong them.H owever,i nt his mutual doping method, it is hard to keep ab alance between the catalytic activity and stability.…”