LAUSR

Development of efficient electrocatalysts for oxygen evolution reaction (OER) is of great significance for future renewable energy applications. Herein, efficient OER electrocatalysts based on iron hydroxide-modified nickel hydroxylphosphate (NiPO/Fe(OH) x) single-wall nanotubes (SWNTs) have been prepared by a facile stepwise surfactant-free solvothermal strategy, which possess diameters of about 6 nm and lengths of about several micrometers. Benefiting from the synergistic effect between iron hydroxides and NiPO SWNTs, the as-prepared NiPO/Fe(OH) x SWNTs exhibit higher OER activity than primary NiPO SWNTs. Furthermore, the OER activity with different Fe contents displays a volcano-type shape, and the optimized NiPO/Fe(OH) x SWNTs present excellent activity with a low overpotential of 248 mV to deliver a current density of 10 mA cm-2 and 323 mV to achieve a large current density of 100 mA cm-2, as well as a remarkably low Tafel slope of 45.4 mV dec-1 in 1 M KOH electrolyte. The present work provides valuable insights to improve the OER performance by rational surface modification.