Ambient Fast Synthesis of Superaerophobic/Superhydrophilic Electrode for Superior Electrocatalytic Water Oxidation

Abstract

Developing cost‐effective and facile methods to synthesize efficient and stable electrocatalysts for large‐scale water splitting is highly desirable but remains a significant challenge. In this study, a facile ambient temperature synthesis of hierarchical nickel–iron (oxy)hydroxides nanosheets on iron foam (FF‐FN) with both superhydrophilicity and superaerophobicity is reported. Specifically, the as‐fabricated FF‐FN electrode demonstrates extraordinary oxygen evolution reaction (OER) activity with an ultralow overpotential of 195 mV at 10 mA cm−2 and a small Tafel slope of 34 mV dec−1 in alkaline media. Further theoretical investigation indicates that the involved lattice oxygen in nickel–iron‐based‐oxyhydroxide during electrochemical self‐reconstruction can significantly reduce the OER reaction overpotential via the dominated lattice oxygen mechanism. The rechargeable Zn–air battery assembled by directly using the as‐prepared FF‐FN as cathode displays remarkable cycling performance. It is believed that this work affords an economical approach to steer commercial Fe foam into robust electrocatalysts for sustainable energy conversion and storage systems.

Hierarchical porous NiFe-P@NC as an efficient electrocatalyst for alkaline hydrogen production and seawater electrolysis at high current density

“…The super-hydrophilic nature of the electrodes facilitated close contact with the electrolyte, and thus maximized the active surface area and accelerated the reaction kinetics. [75][76][77] The HER activity of the synthesized samples was evaluated in a typical three-electrode system in KOH solution (1.0 M). As shown in Fig.…”

“…The super-hydrophilic nature of the electrodes facilitated close contact with the electrolyte, and thus maximized the active surface area and accelerated the reaction kinetics. 75–77…”

Unraveling the Fundamental Concepts of Superaerophobic/Superhydrophilic Electrocatalysts for Highly Efficient Water Electrolysis: Implications for Future Research

“…Impressively, the obtained FF‐FN with superhydrophilic and superaerophobic surface is conducive to the acceleration of electrolyte transfer and could eliminate the O 2 bubble accumulation on the electrode surface. Benefiting from the optimized catalyst composition, superhydrophilic and superaerophobic surface properties, the nanoflower‐like FF‐FN electrode demonstrates extraordinary oxygen evolution reaction activity in alkaline media and realized enhanced Faraday efficiency under high current density [27] . The characteristic of superhydrophobic electrode can be further used to promote the reactivity of the nitrogen release reaction, which plays an important role in hydrazine‐based fuel cells.…”

“…Benefiting from the optimized catalyst composition, superhydrophilic and superaerophobic surface properties, the nanoflower-like FF-FN electrode demonstrates extraordinary oxygen evolution reaction activity in alkaline media and realized enhanced Faraday efficiency under high current density. [27] The characteristic of superhydrophobic electrode can be further used to promote the reactivity of the nitrogen release reaction, which plays an important role in hydrazine-based fuel cells. For the hydrazine fuel cells, the half-cell reaction is also impeded by the performance degradation caused by the nitrogen bubbles adhering to the electrode surface.…”

Versatile, Stable, and Scalable Gel‐Like Aerophobic Surface System (GLASS) for Hydrogen Production

“…Gas evolution reactions are essential for current and next-generation electrochemical energy conversion and storage devices, such as water electrolyzers, [1,2] chloralkali electrolyzers, [3,4] rechargeable metalair batteries, [5,6] and fuel cells. [7,8] Examples of such reactions include hydrogen evolution reactions (HER), [9,10] oxygen evolution reactions (OER), [11,12] chlorine evolution reactions, [13,14] and hydrazine oxidation reactions (HzOR). [15][16][17] Conventional studies on gas evolution reactions have mostly focused on developing electrocatalysts with high activity [18,19] and stability [20,21] by controlling their intrinsic properties, such as structure, [22] composition, [23] defect, [24] and electronic properties.…”