Two-dimensional metallic MoS2-amorphous CoNi(OH)2 nanocomposite for enhanced electrochemical water splitting in alkaline solutions

Abstract

We report the preparation of nanocomposite consisting of metallic MoS2 and electrodeposited amorphous CoNi(OH)2 nanosheets on carbon paper for efficient electrochemical water splitting in the alkaline solutions. The synergistic effect between metallic MoS2 and amorphous CoNi(OH)2 nanosheets enables the excellent catalytic activity of nanocompsite towards hydrogen evolution reaction (HER) in 0.1 M KOH with a low overpotential of 178 mV at a current density of 10 mA/cm2 and Tafel slope of 60.9 mV/decade. The current density of MoS2-CoNi(OH)2 nanocomposite for HER at the overpotential of more than 0.190 V is even higher than that of the commercial Pt/C catalyst. Moreover, the MoS2-CoNi(OH)2 nanocomposite is also active towards electrochemical oxygen evolution and can act as a bifunctional catalyst for water splitting in 0.1 M KOH. Our work povides a simple and effective way to engineer phases and prepare two-dimensional nanocomposites for effecient water splitting in alkaline aqueous solutions.