Synergistic effect between 1D Co3S4/MoS2 heterostructures to boost the performance for alkaline overall water splitting

The reasonable design and construction of hetero-bimetal sulfides with high performance for the oxygen/hydrogen evolution reaction (O/HER) in an alkaline electrolyte are promising but still challenging. Herein, 1D Co3S4/MoS2 bimetallic sulfide nanorods (Co3S4/MoS2 NRs) were prepared using MoO3 nanorods and ZIF-67 as the precursors. As-prepared Co3S4/MoS2 NRs showed excellent HER and OER activity, including low overpotentials at 10 mA cm(-2) (116 and 280 mV) and Tafel slopes (59 and 52 mV dec(-1)). Furthermore, the density functional theory (DFT) reveals that the introduction of Co3S4 is conducive to reducing H2O dissociation during the HER process. In addition, Co3S4 also can effectively regulate the d orbital electrons of Mo in MoS2, which is beneficial for optimizing the H adsorption energy, thus enhancing the HER performance. Benefitting from excellent OER and HER activities, the Co3S4/MoS2 NR based-electrolyzer for overall water spitting exhibits a low cell voltage of 1.66 V to reach 20 mA cm(-2) along with good stability.

Automated summary

The rational design and synthesis of 1D Co3S4/MoS2 bimetallic sulfide nanorods show excellent performance for the hydrogen/oxygen evolution reaction. The introduction of Co3S4 is found to enhance water dissociation during the HER process according to density functional theory, offering new insights for preparing high-performance electrolyzers.