Wang Pan, Luo Yuanzhi, Zhang Gaixia, Wu Mingjie, Chen Zhangsen, Sun Shuhui, Shi Zhicong
Institute of Batteries, School of Materials and Energy, Guangdong University of Technology, Guangzhou, 510006, China.
The Key Laboratory of Fuel Cell Technology of Guangdong Province, School of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou, 510641, China.
Small. 2022 Feb;18(7):e2105803. doi: 10.1002/smll.202105803. Epub 2021 Dec 10.
Exploring highly active and stable bifunctional water-splitting electrocatalysts at ultra-high current densities is remarkably desirable. Herein, 3D nickel-iron phosphides nanosheets modified by MnO nanoparticles are grown on nickel foam (MnO /NiFeP/NF). Resulting from the electronic coupling effect enabled by interface modifications, the intrinsic activities of the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) are improved. Meanwhile, 3D nanosheets provide abundant active sites for HER and OER, leading to accelerating the reaction kinetics. Besides, the shell-protection characteristic of MnO improves the durability of MnO /NiFeP/NF. Therefore, MnO /NiFeP/NF shows exceptional bifunctional electrocatalytic activities toward HER (an overpotential of 255 mV at 500 mA cm ), OER (overpotentials of 296 and 346 mV at 500 and 1000 mA cm , respectively), and overall water splitting (cell voltages of 1.796 and 1.828 V at 500 and 1000 mA cm , respectively). Furthermore, it owns remarkably outstanding stability for overall water splitting at ultra-high current densities (120 and 70 h at 500 and 1000 mA cm , respectively), which outperforms almost all of the non-noble metal electrocatalysts. This work presents efficient strategies of interface modifications, 3D nanostructures, and shell protection to afford ultra-high current densities.
探索在超高电流密度下具有高活性和稳定性的双功能析水电催化剂是非常有必要的。在此，通过MnO纳米颗粒修饰的三维镍铁磷化物纳米片生长在泡沫镍上（MnO/NiFeP/NF）。由于界面修饰产生的电子耦合效应，析氢反应（HER）和析氧反应（OER）的本征活性得到提高。同时，三维纳米片为HER和OER提供了丰富的活性位点，从而加快了反应动力学。此外，MnO的壳层保护特性提高了MnO/NiFeP/NF的耐久性。因此，MnO/NiFeP/NF对HER（在500 mA cm时过电位为255 mV）、OER（在500和1000 mA cm时过电位分别为296和346 mV）以及全水解（在500和1000 mA cm时电池电压分别为1.796和1.828 V）表现出优异的双功能电催化活性。此外，它在超高电流密度下对全水解具有非常出色的稳定性（在500和1000 mA cm时分别为120和70 h），这几乎优于所有非贵金属电催化剂。这项工作提出了界面修饰、三维纳米结构和壳层保护等有效策略以实现超高电流密度。
