Metal

Catalysis

Oxygen evolution

Engineering

Electrochemistry

Materials science

Graphene

Water splitting

Transition metal

Biochemistry

Inorganic chemistry

Chemical engineering

Electrocatalyst

Physical chemistry

Nanowire

Nanotechnology

Tafel equation

Organic chemistry

Noble metal

Nanomaterials

Chemistry

Electrode

Anode

Photocatalysis

Overpotential

Journal of Electroanalytical Chemistry

Precious metal-free electrocatalysts based on two-dimensional nanomaterials have efficiently been used for oxygen evolution reaction; however, the low activity and stability of these materials as compared with noble metals are still distractive. We present a novel and high-performance electrocatalyst based on nanowires of mixed transition metal oxysulfide supported by three-dimensional highly porous graphene networks. Electrochemical studies indicated that the high electron transport medium of nanowires and bilayer graphene nanosheets as well as their high active surface area promote the kinetics of oxygen evolution reaction (OER). A quite small overpotential of 260 mV at the current density of 20 mA.cm−2 in 1.0 M NaOH is achieved, which outperforms most of the current carbon-based supported nanostructured electrocatalysts. The electrocatalyst is also very stable in the alkaline medium with a low Tafel slope of 56.8 mV dec−1 and turnover frequency (TOF) of 0.85 mol O2 per sec. These figures of merit demonstrate the higher performance of the hybrid anode over other noble metal-free electrocatalysts based on both carbon and metal nanostructures.

3D self-supporting mixed transition metal oxysulfide nanowires on porous graphene networks for oxygen evolution reaction in alkaline solution