Durability over 11 days in electrocatalytic hydrogen evolution reaction via designing a 3D magnetic electrode and regulating the electronic structure

Abstract

Most catalysts used for the hydrogen evolution reaction (HER) possess superior electrocatalysis activities but suffer from poor stability, hampering their applications in the electrolysis industry. Here, we fabricated three magnetic electrodes: “H2-catalyst-I” (NiCoFeP@F-NiCoAlFe-LDHs@NiCoFe), “H2-catalyst-II” NiCoFeP@F-NiCoAlFe-LDHs@NiCoFe and NiCoFe), and “H2-catalyst-III” (H2-catalyst-I@poly(3,4-ethylene dioxythiophene) (PEDOT)), to study the effect of magnet field on the electrocatalysis life of NiCo-based phosphides. Among them, the magnetic H2-catalyst-II electrode demonstrates extended stability over 10 days due to the protection effect of NiCoFe alloy powders under a magnetic field, surpassing that of the magnetic H2-catalyst-I electrode. The magnetic H2-catalyst-III electrode exhibits enhanced HER behaviors (η10 = 106 mV, a little Tafel slope of 79 mV·dec-1, and durability for up to 11 days). This stability can be attributed to its strong electron structure nature due to both the magnetic field and the PEDOT coating layer. Finally, an electrolytic cell is assembled by applying the magnetic H2-catalyst-III cathode and F-doped NiCoAl-LDHs@ZnFeAl-LDHs/NF anode and displays the electrocatalysis life over 10 days. In conclusion, the magnetic field holds a beneficial effect on strengthening the electron structure of the catalyst, thereby extending the lifespan of HER, which introduces a new approach for designing and preparing robust HER catalysts to meet the demands in the electrolysis water industry.