NC/Ni–Co3O4@Co1−xS Nanosheet Prepared from Metal Organic Framework for Highly Efficient Overall Water Splitting

It is important to develop active, stable, and cost-effective electrocatalysts for highly efficient overall water splitting. Metal organic frameworks were considered as efficient precursors for overall water splitting catalysts. In this paper, NC/Ni–Co 3 O 4 @Co 1−x S with small size is obtained from ZIF-67. NC/Ni–Co 3 O 4 @Co 1−x S materials exhibit superior overall water splitting properties, with a low overpotential of 170 mV for the hydrogen evolution reaction at 10 mA cm −2 and 210 mV for the oxygen evolution reaction at 10 mA cm −2 and long-term stability. Furthermore, the overall water splitting only requires 1.64 V to drive the current density of 10 mA cm −2 , when the NC/ Ni–Co 3 O 4 @Co 1−x S are used as both anode and cathode. NC/Ni–Co 3 O 4 @Co 1−x S has excellent electrocatalytic activity due to its nanosheet structure, which greatly increases the electrochemically active surface area and the NC/Ni–Co 3 O 4 @Co 1−x S has good electrical conductivity and abundant Co 3+ sites, so the electrocatalytic activity is significantly enhanced. This study provides a new idea for the design and synthesis of novel composite electrocatalysts. Graphical