Turning Waste into Treasure: Regulating the Oxygen Corrosion on Fe Foam for Efficient Electrocatalysis

Abstract

Iron corrosion causes a great damage to the economy due to the function attenuation of iron‐based devices. However, the corrosion products can be used as active materials for some electrocatalytic reactions, such as oxygen evolution reaction (OER). Herein, the oxygen corrosion on Fe foams (FF) to synthesize effective self‐supporting electrocatalysts for OER, leading to “turning waste into treasure,” is regulated. A dual chloride aqueous system of “NaCl‐NiCl2” is employed to tailor the structures and OER properties of corrosion layers. The corrosion behaviors identify that Cl− anions serve as accelerators for oxygen corrosion, while Ni2+ cations guarantee the uniform growth of corrosion layers owing to the appeared chemical plating. The synergistic effect of “NaCl‐NiCl2” generates one of the highest OER activities that only an overpotential of 212 mV is required to achieve 100 mA cm−2 in 1.0 m KOH solution. The as‐prepared catalyst also exhibits excellent durability over 168 h (one week) at 100 mA cm−2 and promising application for overall water splitting. Specially, a large self‐supporting electrode (9 × 10 cm2) is successfully synthesized via this cost‐effective and easily scale‐up approach. By combining with corrosion science, this work provides a significant stepping stone in exploring high‐performance OER electrocatalysts.

Transforming Damage into Benefit: Corrosion Engineering Enabled Electrocatalysts for Water Splitting

“…[ 72 ] In addition, the metal corrosion is also affected by the concentrations of reaction solutions. For example, our group [ 73 ] has effectively manipulated the morphologies and compositions of iron foam based electrocatalysts by tailoring the concentrations of NaCl and NiCl 2 solutions ( Figure a–g). Generally, the large concentrations improve solution conductivity and provide sufficient reactants on the interfaces to expedite the corrosion process.…”

“…Reproduced with permission. [ 73 ] Copyright 2020, Wiley. SEM images of the NiFe(OH) x /FeS/IF electrodes synthesized in NiCl 2 solution h) with oxygen gas and i) without oxygen gas.…”

“…To deeply study the reaction mechanism of IF in the Ni 2+ ‐containing solution, our group [ 73 ] had systematically investigated the autogenous growth of corrosion layers of IF in NaCl–NiCl 2 solutions by regulating the oxygen corrosion, as shown in Figure a. The compositions and morphologies of corrosion layers were regulated just by changing solution concentrations of NaCl and NiCl 2 .…”

Coupling Hierarchical Ultrathin Co Nanosheets With N-Doped Carbon Plate as High-Efficiency Oxygen Evolution Electrocatalysts

“…Urged by the ever-increasing consumption of fossil fuels and environmental pollution problems, numerous efforts have been put to design new renewable energy materials and technologies (Liu et al, 2020;Zheng et al, 2020). Electrocatalytic oxygen evolution reaction (OER, 4OH − → 2H 2 O + O 2 + 4e − ) always draws significant attention in the scientific community because it plays a great crucial role in the development of energy conversion and storage technologies (e.g., metal-air batteries, water splitting devices) (Lyu et al, 2019;Yin et al, 2020).…”

“…In recent years, as a potential substitute for commercial IrO 2 and RuO 2 catalysts, noble-metal-free-based catalysts have been widely researched. Among them, earth-abundant Co-based electrocatalysts, including oxides (Li T. et al, 2019;, sulfides (Dong et al, 2019;Fragal et al, 2019), phosphides (Jin et al, 2019;Li M. et al, 2020), nitrides (Ouyang et al, 2019;Yang et al, 2019b), layered double hydroxides (LDHs) (Yu et al, 2017;Dionigi et al, 2020), metal-organic frameworks (MOFs) (Chen et al, 2017;Kang et al, 2019), single atoms (Yang et al, 2018;Zang et al, 2018), etc., have been proven to have a low price and good electrocatalytic activity toward OER process (Yang et al, 2019a;Zhao et al, 2020;Zhu et al, 2020). In particular, Co species supported on carbonaceous materials, such as nitrogen-doped carbon nanotubes (NCNTs) (Zhao et al, 2018;Huang et al, 2020), reduced graphene oxide (rGO) (Li Y. et al, 2018), and porous carbon (Fu et al, 2018d) electrocatalysts have demonstrated greatly enhanced electrocatalytic activity and stability.…”