Boosting the Oxygen Evolution Reaction via the Reconstruction of M(OH)x/Fe3O4 Catalyst

Abstract

For large-scale hydrogen production from electrocatalysis of water, the Ni- and/or Fe-based catalysts were commonly used but limited by the ultrahigh overpotential and poor stability at high current density (>500 mA cm−2). Here, the reconstruction of M(OH)x/Fe3O4 (M = Ni, Fe) arrays has been fabricated for boosting the oxygen evolution reaction (OER). The prepared M(OH)x/Fe3O4 grewon iron foam (M(OH)x/Fe3O4/IF) catalysts exhibited low overpotentials of 214 and 311 mV for OER at the current densities of 50 and 500 mA cm−2, respectively, besides the excellent stability up to 70 h of operation at a current density of 10 mA cm−2 in 1 M KOH. The in situ Raman spectra revealed that, the reconstruction of M(OH)x/Fe3O4/IF boosted the OER activity. Theoretical calculation revealed favorable absorption of O2 at Ni site of M(OH)x/Fe3O4/IF during OER. This work highlights the reconstruction structurally definite catalysts for promoting the catalytic activity toward OER and the large-scale electrocatalysis of water.