Highly efficient, field-assisted water splitting enabled by a bifunctional Ni3Fe magnetized wood carbon

Various strategies have been used to improve the performance of non-noble catalysts, such as alloying, doping, and fine structure modulations. Herein, we reported a magnetic field-enhanced, bifunctional Ni 3 Fe/wood carbon electrode (Ni 3 Fe-CW) for efficient overall water splitting. Wood with numerous porous channels allows high loading of metal ions via the hydrothermal method, while the following high-temperature calcination leads to well-dispersed and uniform Ni 3 Fe nanoparticles , which are both electrocatalytically and magnetically active. As a result, the Ni 3 Fe-CW shows low overpotentials of 237 mV and 76 mV at 10 mA cm −2 for both oxygen and hydrogen evolutions under magnetic field (300 mT by a permanent magnet). Density functional theory calculations demonstrate that the Ni 3 Fe exhibits strong spin polarization under magnetic field with accelerated electron transfer , leading to lower reaction energy barrier and enhanced catalytic activities . Importantly, the electrolytic cell constructed by the bifunctional Ni 3 Fe-CWs as both cathode and anode displays a low cell voltage of 1.54 V at 10 mA cm −2 with an appropriate stability over 50 h (with a passive magnet). Considering the ubiquitous application of magnetic Fe, Co, Ni in catalytic reactions and the passive-radiation role of magnet, our strategy is promising for many energy conversion technologies toward highly efficient catalysis.