Construction of Self-Supporting NiCoFe Nanotube Arrays Enabling High-Efficiency Alkaline Oxygen Evolution

Abstract

Enhancing the intrinsic activity and modulating the electrode− electrolyte interface microenvironment of nickel-based candidates are essential for breaking through the sluggish kinetics limitation of the oxygen evolution reaction (OER). Herein, a ternary nickel−cobalt−iron solid solution with delicate hollow nanoarrays architecture (labeled as NiCoFe-NTs) was designed and fabricated via a ZnO-templated electrodeposition strategy. Owing to the synergistic nanostructure and composition feature, NiCoFe-NT presents desirable alkaline OER performance, with a η 10 and η 500 of 187 and 310 mV, respectively, along with favorable long-term durability. In-depth analyses identify the heterogeneous nickelbased (oxy)hydroxide species derived from the oxidative reconstruction acting as an active contributor for oxygen evolution. Impressively, the regulatory mechanism of the catalytic performance by a rationally designed nanostructure was elucidated by compressive analyses; that is, the faster gas release processes induced by nanotube arrays can modulate the heterogeneous interface states during OER, which effectively facilitates the electrochemical charge−mass transfer to promote the reaction kinetics. To assess the practical feasibility, an alkaline water electrolyzer and a CO 2 electrochemical reduction flow cell were constructed by coupling the anodic NiCoFe-NTs and cathodic nickel phosphides (Ni 2 P-NF) and metallic Cu electrocatalysts, respectively, both of which achieved high-efficiency operation.

In situelectronic redistribution of NiCoZnP/NF heterostructureviaFe-doping for boosting hydrazine oxidation and hydrogen evolution

“…[1][2][3][4] Hydrogen, a sustainable and green energy carrier, has received considerable attention for decades. [5][6][7][8][9] Among the various methods for hydrogen generation, electrochemical splitting of water is considered to be a critical pathway toward H 2 production due to its carbon-free nature. However, the oxygen evolution reaction (OER) is a fourelectron transfer process, which requires a large overpotential and hinders practical H 2 generation.…”

Interface Engineering of a Hierarchical P-Modified Co/Ni3P Heterostructure for Highly Efficient Water Electrolysis Coupled with Hydrazine Degradation

“…Various TM-based materials, including alloys, heterostructure compounds, or high-entropy compounds, have been anchored directly to the surface of the replaceable working substrates, avoiding the use of additional adhesives to improve the structure stability. – For instance, NiCoP@NiS nanoarrays with a core–shell structure were developed by a simple electrodeposition method, which exhibited unique advantages of improved electron transfer and reaction kinetics for catalysis . In addition, the electrodeposition synthesis of self-supporting NiCoFe nanotube arrays was reported by Yang’s group, who achieved faster charge-mass-transfer ability due to the unique electrode structure . Therefore, the electrodeposition method shows the competitiveness of rapid design of self-supporting heterostructured electrocatalysts, but traditional electrodeposition techniques lack reasonable regulation of the morphology and structure of the catalyst, resulting in the limitation of their catalytic performance.…”

“…47 In addition, the electrodeposition synthesis of self-supporting NiCoFe nanotube arrays was reported by Yang's group, who achieved faster charge-mass-transfer ability due to the unique electrode structure. 48 Therefore, the electrodeposition method shows the competitiveness of rapid design of self-supporting heterostructured electrocatalysts, but traditional electrodeposition techniques lack reasonable regulation of the morphology and structure of the catalyst, resulting in the limitation of their catalytic performance. The development of novel tunable electrodeposition strategies is the ideal approach to further promote the catalytic performance of self-supporting TM-based electrodes for the hydrazineassisted HER process.…”

MoO2/Ni0.2Mo0.8N nanorods on nickel foam as a high performance electrocatalyst for efficient water oxidation

“…1,2 Among these two reactions, the OER mainly faces the challenge of high activation energy barrier due to the four-electron transfer and the formation of the oxygen-oxygen bond, leading to sluggish OER. 3,4 Despite Ru and Ir (including their oxides) being ideal catalysts for the OER, their high-cost and poor stability not only hinder their commercial application but also lead to the development of cost-effective catalysts, such as transition metal compounds. [5][6][7] Among various catalysts, heterogeneous transition metal oxide (TMOs) and nitride (TMNs) catalysts, including NiO/ CoN, 8 Ni 3 Mo 3 N-MoO 2 -NiO, 9 and CoO/CoN, 10 have been reported as OER catalysts.…”