Ru nanoparticles decorating ferrocene-based metal-organic framework for efficient and stable water-splitting electrocatalyst

Abstract

The development of stable and efficient electrocatalysts based on metal-organic frameworks represents a main challenge for the overall water splitting process. Here, the ferrocene-based nickel metal-organic framework (NiFc-MOF) on nickel foam (NF) was synthesized using nickel chloride and 1, 1′-ferrocenedicarboxylic acid (FcDA) via a simple solvothermal method, and Ru nanoparticles (NPs) were reduced by FcDA and in situ grown on the surface of NiFc-MOF nanosheets. The as-prepared cactus-like Ru0.3@NiFc-MOF exhibits high electrocatalytic activity for hydrogen evolution reaction (HER) with a low overpotential of 25 mV@10 mA cm−2 and a Tafel slope of 45.05 mV dec−1. To reach a current density of 10 mA cm−2 for the oxygen evolution reaction (OER), a low overpotential of 210 mV was required. The assembled water electrolysis cell using Ru0.3@NiFc-MOF as bifunctional electrocatalysts only requires a voltage of 1.47 V to achieve a current density of 10 mA cm−2, indicating excellent electrolytic water splitting performance. In addition, the electrocatalytic activity of Ru0.3@NiFc-MOF's can keep the stability for 120 h Ru0.3@NiFc-MOF exhibits exceptional electrocatalytic performance, which can be attributed to both the intrinsic activity of Ru sites and the multiple active sites of NiFc-MOF.