Professor Genban Sun of the Center for Advanced Materials Research and his team published their research in the Journal of the American Chemical Society (JACS) : Regulating the Spin State of FeIII Enhances the Magnetic Effect of the Molecular Catalysis Mechanism.
Aqueous-phase oxygen evolution reaction (OER) is the bottleneck of water splitting. The formation of the O–O bond involves the generation of paramagnetic oxygen molecules from the diamagnetic hydroxides. The spin configurations might play an important role in aqueous-phase molecular electrocatalysis. Although the spin-related OER enhancement has already been observed, it has rarely been systematically and comprehensively demonstrated. Therefore, spintronic electrocatalysis is still a relatively blank field of catalysis.
Figure 1. Spin splitting design strategy and catalytic mechanism of magnetic Fe3+
Based on the above problems, the team of Professor Genban Sun, Center for Advanced Materials Research, Beijing Normal University, has made important progress in the research of NiFe-layered double hydroxides (NiFe–LDHs) as OER catalysts: a novel magnetic FeIII site spin-splitting strategy has been proposed, wherein the electronic structure and spin states of the FeIII sites are effectively induced and optimized by the Jahn–Teller effect of Cu2+. The theoretical calculations and operando attenuated total reflectance-infrared Fourier transform infrared (ATR FT-IR) reveal the facilitation for the O–O bond formation, which accelerates the production of O2 from OH– and improves the OER activity. The Cu-NiFe-LDHs catalyst exhibits a low overpotential of 210 mV at 10 mA cm–2 and a low Tafel slope (33.7 mV dec–1), better than those of the initial Cu-NiFe-LDHs (278 mV, 101.6 mV dec–1). With the Cu2+ regulation, we have realized the transformation of NiFe–LDHs from ferrimagnets to ferromagnets and showcase that the OER performance of Cu–NiFe–LDHs significantly increases compared with that of NiFe–LDHs under the effect of a magnetic field for the first time. The magnetic-field-assisted Cu-NiFe-LDH provide an ultralow overpotential of 180 mV at 10 mA cm–2, which is currently one of the best OER performances. The combination of the magnetic field and spin configuration provides new principles for the development of high-performance catalysts and understandings of the catalytic mechanism from the spintronic level.
Figure 2. Magnetic field assisted enhanced catalytic oxygen evolution reaction performance
The work was recently accepted for publication in the JACS, a comprehensive Journal of chemistry. The JACS is one of the world’s most important academic journals in the field of chemistry. Together with Angewandte Chemie International Edition, it is recognized as one of the most influential journals in the field of chemistry.
Beijing Normal University is the first completion unit. The research was supported by the National Natural Science Foundation of China, Center for Advanced Materials Research, College of Chemistry, Advanced Research Institute of Natural Science, Experimental and Practical Innovation Education Center. Professor Genban Sun is the corresponding author, and Dr. Zemin Sun and Dr. Liu Lin are the co-first authors.