2D organ-like molybdenum carbide (MXene) coupled with MoS2 nanoflowers enhances catalytic activity in the hydrogen evolution reaction
Two-dimensional (2D) carbides, nitrides and carbonitrides called MXene are noval materials with a lot of useful applications. However, the range of transition metals capable of forming stable MXenes is limited mostly to early transition metals of 3rd-5th groups. To deal with the inaccessibility of MXene phases derived from mid transition metals, we have developed a synthetic strategy that preparing Mo2Ga2C crystal and 2D organ-like Mo2C MXene matrix coupled with MoS2 nanoflowers. Compared with Mo2CTx (where Tx are O, OH, and F surface terminations) MXene catalyst, MoS2@Mo2CTx nanohybrids showed significantly enhanced hydrogen evolution reaction (HER) activity in alkaline media, with a low overpotential of 176 mV at the current density of 10 mA cm-2 and a very small transfer resistance of 26 Ω. Density functional theory (DFT) calculations attribute the enhanced reaction kinetics of MoS2@Mo2CTx to the favorable binding of hydrogen on the oxygen terminated Mo2C surface, which is strongly influenced by MoS2. The synthetic approach illustrates that tailoring the properties of MXenes for a specific application can be achieved via preparing organ-like molybdenum carbide coupled with MoS2 nanoflowers.