Dual synergistic effect of S-doped carbon bridged semi crystalline MILN-based Co3S4/MnS2 nanostructure in electrocatalytic overall water splitting

Abstract

Rapid electron transfer and abundant existence of active center are the keys for high performance catalysts. Here, an efficient bifunctional electrocatalyst, S-doped carbon bridged semi crystalline MILN-based Co3S4/MnS2 nanostructure prepared from MIL-88B(Co/Mn)-NH2 is constructed for overall water splitting. This catalyst not only acquires additional reaction sites through the dispersion of the metal centers, but also achieves fast delivery of electrons between Co3S4 and MnS2 through the S-doped carbon bridge. The strong electron donating ability of -NH2 and S2− and the excellent valence changing ability of two different transition metal centers make this material achieve a dual synergistic effect, greatly promoting the overall water splitting performance of the catalyst. In addition, high catalytic ability for HER is attribute to the amorphous component in the semicrystal MILN-based Co3S4/MnS2. The operation of water splitting by this catalyst with synergistic effect obtained a current density of 20 mA cm−2 at a low voltage of 1.561 V and a stable operation for 80 h. This work provides a new insight into the design of MOF-based electrocatalytic materials for electrochemical water splitting.