Ferromagnetic single-atom spin catalyst for boosting water splitting

Autor: Sun, Tao, Tang, Zhiyuan, Zang, Wenjie, Li, Zejun, Li, Jing, Li, Zhihao, Cao, Liang, Dominic Rodriguez, Jan Sebastian, Mariano, Carl Osby M., Xu, Haomin, Lyu, Pin, Hai, Xiao, Lin, Huihui, Sheng, Xiaoyu, Shi, Jiwei, Zheng, Yi, Lu, Ying-Rui, He, Qian, Chen, Jingsheng, Novoselov, Kostya S., Chuang, Cheng-Hao, Xi, Shibo, Luo, Xin, Lu, Jiong
Zdroj: Nature Nanotechnology; July 2023, Vol. 18 Issue: 7 p763-771, 9p
Abstrakt: Heterogeneous single-atom spin catalysts combined with magnetic fields provide a powerful means for accelerating chemical reactions with enhanced metal utilization and reaction efficiency. However, designing these catalysts remains challenging due to the need for a high density of atomically dispersed active sites with a short-range quantum spin exchange interaction and long-range ferromagnetic ordering. Here, we devised a scalable hydrothermal approach involving an operando acidic environment for synthesizing various single-atom spin catalysts with widely tunable substitutional magnetic atoms (M1) in a MoS2host. Among all the M1/MoS2species, Ni1/MoS2adopts a distorted tetragonal structure that prompts both ferromagnetic coupling to nearby S atoms as well as adjacent Ni1sites, resulting in global room-temperature ferromagnetism. Such coupling benefits spin-selective charge transfer in oxygen evolution reactions to produce triplet O2. Furthermore, a mild magnetic field of ~0.5 T enhances the oxygen evolution reaction magnetocurrent by ~2,880% over Ni1/MoS2, leading to excellent activity and stability in both seawater and pure water splitting cells. As supported by operando characterizations and theoretical calculations, a great magnetic-field-enhanced oxygen evolution reaction performance over Ni1/MoS2is attributed to a field-induced spin alignment and spin density optimization over S active sites arising from field-regulated S(p)–Ni(d)hybridization, which in turn optimizes the adsorption energies for radical intermediates to reduce overall reaction barriers.
Databáze: Supplemental Index
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