Spin regulation on (Co,Ni)Se2/C@FeOOH hollow nanocage accelerates water oxidation

• Published in: Chinese journal of catalysis 2022-03, Vol.43 (3), p.839-850
• Main Authors: Gu, Yu, Wang, Xiaolei, Humayun, Muhammad, Li, Linfeng, Sun, Huachuan, Xu, Xuefei, Xue, Xinying, Habibi-Yangjeh, Aziz, Temst, Kristiaan, Wang, Chundong
• Format: Article
• Language: English
• Subjects: d-Orbital electron; FeOOH; Hollow nanocage; Oxygen evolution reaction; Spin engineering
• ISSN: 1872-2067; 1872-2067
• DOI: 10.1016/S1872-2067(21)63922-0

Spin engineering is recognized as a promising strategy that modulates the association between d-orbital electrons and the oxygenated species, and enhances the catalytic kinetics. However, few efforts have been made to clarify whether spin engineering could make a considerable enhancement for electrocatalytic water oxidation. Herein, we report the spin engineering of a nanocage-structured (Co,Ni)Se2/C@FeOOH, that showed significant oxygen evolution reaction (OER) activity. Magnetization measurement presented that the (Co,Ni)Se2/C@FeOOH sample possesses higher polarization spin number (μb = 6.966 μB/f.u.) compared with that of the (Co,Ni)Se2/C sample (μb = 6.398 μB/f.u.), for which the enlarged spin polarization number favors the adsorption and desorption energy of the intermediate oxygenated species, as confirmed by surface valance band spectra. Consequently, the (Co,Ni)Se2/C@FeOOH affords remarkable OER product with a low overpotential of 241 mV at a current of 10 mA cm−2 and small Tafel slope of 44 mV dec−1 in 1.0 mol/L KOH alkaline solution, significantly surpassing the parent (Co,Ni)Se2/C catalyst. This work will trigger a solid step for the design of highly-efficient OER electrocatalysts. Coupling FeOOH with (Co,Ni)Se2/C allows introduction of numerous polarized spins into the composites and consequently endows remarkable OER activity, which could be due to the optimized adsorption and desorption energy of the intermediate oxygenated species by spin engineering.