Unique-Structure MoS2 Grow on Nickel Foam As Highly Efficient Self-Supported Electrode for Oxygen Evolution Reaction

Growing demand for sustainable, clean, efficient energy conversion system has derived tremendous interest to develop cost-effective and highly efficient electrocatalysts for oxygen evolution reaction (OER). Sulfides have recently attracted great attention due to their highly efficient electrocatalytic activity. MoS 2 has been verified as an efficient catalyst toward OER because of its durability, cost-efficiency and high activity. However, binder and extra conductive materials are required to attach electrocatalyst on a conductive substrate which will result in restricted active surface areas, undesirable interfaces and lots of dead volumes. Binder-free self-supported material can eliminate these problems. Herein, we synthesize self-supported binder-free MoS 2 on 3D porous nickel foam (NF) with excellent activity and stability via a facile hydrothermal method. The MoS 2 @NF electrode is tested in 0.1mol KOH by linear sweep voltammetry (LSV), electrochemical surface area (ECSA) and electrochemical impedance spectroscopy (EIS). Compared with different substrates (Cu foam, NF, Cu paper and carbon paper), MoS 2 @NF electrode where NF as substrate shows the lowest overpotential at 10mA cm -2 of 359mV for OER. Furthermore, the overpotential at 10mA cm -2 after 10hr is 419mV, which demonstrates high stability and activity. Such high electrochemical performance may attribute to the following reasons: 1) the large ECSA and good conductivity, that improves utilization of electroactive sites and electron transfer; 2) the unique 3D porous structure, that facilitates electrolyte penetration and reactant/product diffusion; and 3) the sulfur vacancy in MoS 2 , that accelerates the O-H bond breaking.