Eutectic‐Derived Mesoporous Ni‐Fe‐O Nanowire Network Catalyzing Oxygen Evolution and Overall Water Splitting

Abstract

The development of efficient and abundant water oxidation catalysts is essential for the large‐scale storage of renewable energy in the form of hydrogen fuel via electrolytic water splitting, but still remains challenging. Based upon eutectic reaction and dealloying inheritance effect, herein, novel Ni‐Fe‐O‐based composite with a unique mesoporous nanowire network structure is designed and synthesized. The composite exhibits exceptionally low overpotential (10 mA cm−2 at an overpotential of 244 mV), low Tafel slope (39 mV dec−1), and superior long‐term stability (remains 10 mA cm−2 for over 60 h without degradation) toward oxygen evolution reaction (OER) in 1 m KOH. Moreover, an alkaline water electrolyzer is constructed with the Ni‐Fe‐O composite as catalyst for both anode and cathode. This electrolyzer displays superior electrolysis performance (affording 10 mA cm−2 at 1.64 V) and long‐term durability. The remarkable features of the catalyst lie in its unique mesoporous nanowire network architecture and the synergistic effect of the metal core and the active metal oxide, giving rise to the strikingly enhanced active surface area, accelerated electron/ion transport, and further promoted reaction kinetics of OER.

Electroactive Edge‐Site‐Enriched α‐Co0.9Fe0.1(OH)x Nanoplates for Efficient Overall Water Splitting

“…These results are in good agreement with the reported Co(OH) 2 . [29] In addition, the peak at 714.7 eV implies that Fe 3 + exist in more than one coordination environment. The first doublet at 780.6 eV and 796.5 eV and the second doublet at 782.5 eV and 798.0 eV are attributed to the Co 2p 3/2 and Co2p 1/2 of Co 3 + and Co 2 + species, respectively.…”

Flexible Honeycombed Nanoporous/Glassy Hybrid for Efficient Electrocatalytic Hydrogen Generation

“…[12][13][14][15][16][17] The uniform bicontinuous nanoporosity produced by dealloying/etching can offer nanoporous materials satisfactory electrocatalytic activities, high-efficiency electron transportation, and improved selectivity for various redox reactions. [20][21][22][23][24][25] However, the brittleness of the dealloyed nanoporous architectures remains "the Achilles' heel" for their industrialization in flexible/stable electrode devices. [20][21][22][23][24][25] However, the brittleness of the dealloyed nanoporous architectures remains "the Achilles' heel" for their industrialization in flexible/stable electrode devices.…”

Microwave-assisted CVD-like synthesis of dispersed monolayer/few-layer N-doped graphene encapsulated metal nanocrystals for efficient electrocatalytic oxygen evolution

“…As shown in Fig. 4a–d, the FeNi@NC/RGO shows a very low overpotential of 261 mV to reach 10 mA cm –2 and a very small Tafel slope of 40.0 mV dec –1 , indicating that FeNi@NC/RGO possesses highly active reaction sites and also ultrafast OER kinetics 27–30. Moreover, ultrahigh current densities of 50, 100, 150, 200, 250 mA cm –2 could be obtained at the overpotentials of 287, 299, 307, 317 and 326 mV, which is highly encouraging for its practical application.…”