1 T-MoS2/Co3S4/Ni3S2 nanoarrays with abundant interfaces and defects for overall water splitting

Transition-metal chalcogenides especially MoS2 are promising candidates as highly efficient electrocatalyst for hydrogen evolution reaction (HER). Nevertheless, the low conductivity and inert basal planes of MoS2 limit its performance. In addition, the oxygen evolution reaction (OER) catalytic activity of MoS2 is low. In this work, we report the synthesis of self-supported 1 T-MoS2/Co3S4/Ni3S2 nanoarrays for overall water splitting. 1 T-MoS2 can enhance electron transfer during the reaction process. Meanwhile, abundant interfaces and defects exist in the heterogeneous catalysts, which can bring more active sites and result in strong interaction among the different components. As a result, the 1 T-MoS2/Co3S4/Ni3S2 nanoarray exhibits low overpotentials of 50 and 240 mV is achieved at 10 mA cm-2 for HER and OER with very high stability. In addition, it can catalyze overall water splitting with a low cell voltage of 1.55 V and 100% Faradic efficiency, demonstrating its practical applications. The present work offers a new route for developing 1 T-MoS2 based hybrid electrocatalysts with desirable surface and interface structure for energy storage and conversion.

Automated summary

In this work, self-supported 1T-MoS2/Co3S4/Ni3S2 nanoarrays were synthesized for overall water splitting. The 1T-MoS2 enhances electron transfer and the heterogeneous catalysts provide abundant interfaces and defects, resulting in a strong interaction among the different components. The 1T-MoS2/Co3S4/Ni3S2 nanoarray exhibits low overpotentials for both HER and OER with high stability, and it can catalyze overall water splitting with low cell voltage and high Faradic efficiency. This work offers a new route for developing 1T-MoS2 based hybrid electrocatalysts with desirable surface and interface structure for energy storage and conversion.