Tuesday, 30 May 2017
Grand Ballroom (Hilton New Orleans Riverside)
Developing efficient and economical electrocatalysts for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) with readily available metals is one of the main challenges for large scale hydrogen/oxygen production. Here, we report one step synthesis of cobalt and molybdenum hybrid materials for high performance overall water splitting. The binder-free CoS-doped β-Co(OH)2@amorphous MoS2+x is coated on nickel foam (NF) to form 3D networked nanoplates which have large surface area and high durability for electrochemical reactions. The catalytic activity of electrocatalyst for hydrogen evolution is mainly attributed to the unsaturated sulfur site of amorphous MoS2+x. Meanwhile, the CoS-doped β-Co(OH)2 plays the major role in oxygen evolution. CoS-doped β-Co(OH)2 and aMoS2+x are strongly bound to each other due to CoSx bridging. This CoS-Co(OH)2@aMoS2+x/NF hybrid exhibits excellent catalytic activity and stability for overall water splitting. For over 100,000 seconds the cell voltage required to achieve the current density of 10 mA cm-2 is only 1.58 V, which is remarkably low among the commercially available electrocatalysts. Our findings would open up an easy and inexpensive method of large scale fabrication of bifunctional electrocatalysts for overall water splitting.