Shen Xueran, Li Huanjun, Ma Tiantian, Jiao Qingze, Zhao Yun, Li Hansheng, Feng Caihong
Beijing Key Laboratory for Chemical Power Source and Green Catalysis, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing, 100081, P. R. China.
School of Materials and Environment, Beijing Institute of Technology, Jinfeng Road No.6, Xiangzhou District, Zhuhai, 519085, P. R. China.
Small. 2024 Jul;20(30):e2310535. doi: 10.1002/smll.202310535. Epub 2024 Feb 29.
The exploiting electrocatalysts for water/seawater electrolysis with remarkable activity and outstanding durability at industrial grade current density remains a huge challenge. Herein, CoMoN and Fe-doped CoMoN nanosheet arrays are in-situ grown on Ni foam, which possess plentiful holes, multilevel heterostructure, and lavish CoN/MoN@NF and Fe-CoN/MoN@NF interfaces. They require low overpotentials of 213 and 296 mV for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) under alkaline media to achieve current density of 800 mA cm, respectively, and both possess low Tafel slopes (51.1 and 49.1 mV dec) and undiminished stability over 80 h. Moreover, the coupled CoN/MoN@NF and Fe-CoN/MoN@NF electrolyzer requires low voltages of 1.735 V to yield 500 mA cm in alkaline water. Notably, they also exhibit exceptional electrocatalytic properties in alkaline seawater (1.833 V@500 mA cm). The experimental studies and theoretical calculations verify that Fe doping does reduce the energy barrier from OH* to O* intermediates during OER process after catalyst reconstruction, and the non-metallic N site from MoN exhibits the lowest theoretical overpotential. The splendid catalytic performance is attributed to the optimized local electron configuration and porous structure. This discovery provides a new design method toward low-cost and excellent catalysts for water/seawater splitting to produce hydrogen.
开发在工业级电流密度下具有显著活性和出色耐久性的用于水电解/海水电解的电催化剂仍然是一项巨大挑战。在此，CoMoN和Fe掺杂的CoMoN纳米片阵列原位生长在泡沫镍上，其具有大量孔洞、多级异质结构以及丰富的CoN/MoN@NF和Fe-CoN/MoN@NF界面。在碱性介质中，它们对于析氢反应（HER）和析氧反应（OER）分别需要213和296 mV的低过电位来实现800 mA cm的电流密度，并且两者都具有低塔菲尔斜率（51.1和49.1 mV dec）以及在80 h以上的稳定性能。此外，耦合的CoN/MoN@NF和Fe-CoN/MoN@NF电解槽在碱性水中产生500 mA cm需要1.735 V的低电压。值得注意的是，它们在碱性海水中（1.833 V@500 mA cm）也表现出优异的电催化性能。实验研究和理论计算证实，Fe掺杂确实在催化剂重构后的OER过程中降低了从OH到O中间体的能垒，并且来自MoN的非金属N位点表现出最低的理论过电位。出色的催化性能归因于优化的局部电子构型和多孔结构。这一发现为水/海水分解制氢的低成本且优异的催化剂提供了一种新的设计方法。
