Cation modulating electrocatalyst derived from bimetallic metal–organic frameworks for overall water splitting

Abstract

Metal carbides with unique electrical properties and high catalytic efficiency have attracted tremendous interest for applications involving water electrolysis. In this paper the design of a novel cation modulating electrocatalyst Ni₃ZnC_0.7 using homogeneous bimetallic metal–organic frameworks (NiZn-MOFs) as precursor is reported. The synergistic effect between the unique chemical properties and nanostructure endows Ni₃ZnC_0.7 with a remarkable electrocatalytic performance. The balance of Ni(0) and Ni(II) achieved by Zn modulation is beneficial to both the hydrogen evolution reaction and the oxygen evolution reaction under alkaline conditions. The bifunctional catalyst, Ni₃ZnC_0.7, can drive overall water splitting through a symmetrical double electrode at a current density of 10 mA cm⁻² with only 1.65 mV, and also shows excellent stability without obvious degradation after 24 h of operation, which makes it a promising noble metal free electrocatalyst. This easy preparation method for Ni₃ZnC_0.7 makes it a promising candidate for a practical answer to water splitting. Furthermore, this cation modulating strategy provides an ingenious way to realize the precise control of the catalysts and can be extended to the synthesis of various novel nanomaterials.