Defect-rich MoS2/CoS2 on Mo2TiC2Tx MXene as an efficient catalyst for hydrogen evolution reaction in acidic media

Electrocatalytic hydrogen production is an effective way to produce hydrogen energy, and the key is to find inexpensive and effective catalysts. Loading transition metal sulfides onto two-dimensional transition metal carbide (MXene) is an effective method to prepare cheap and high-performance hydrogen evolution reaction (HER) catalysts. In this study, Mo 2 TiAlC 2 was etched with hydrofluoric acid to prepare Mo 2 TiC 2 T x MXene, which was then composited with MoS 2 and CoS 2 to prepare defect-rich MoS 2 /CoS 2 @Mo 2 TiC 2 T x composite by a hydrothermal method. MoS 2 /CoS 2 provides a large number of active sites for electrocatalysis, while Mo 2 TiC 2 T x MXene as a carrier not only provides nucleation and growth sites for MoS 2 /CoS 2 , but also increases the rate of electron transfer in HER process, which achieves good synergy between MoS 2 /CoS 2 and Mo 2 TiC 2 T x MXene. Consequently, MoS 2 /CoS 2 -2@Mo 2 TiC 2 T x exhibits an excellent HER performance. When the current density reaches 10 mA cm −2 , the optimal MoS 2 /CoS 2 -2@Mo 2 TiC 2 T x catalyst only requires an overpotential of 80 mV, and exhibits good cycling stability and durability. This work gives a new idea for the preparation of efficient HER catalysts using non-precious metal composites to replace the precious Pt/C.