Hierarchical "nanoroll" like MoS2/Ti3C2Tx hybrid with high electrocatalytic hydrogen evolution activity.

Graphical abstract Highlights • Hierarchical "nanoroll" like MoS 2 /Ti 3 C 2 T x hybrid was prepared by combining liquid nitrogen-freezing and subsequent annealing. • The hierarchical MoS 2 /Ti 3 C 2 Tx hybrid exhibit excellent HER catalytic activity with a small onset overpotential of 30 mV. • More than 25-fold increase in the exchange current density of the MoS 2 /Ti 3 C 2 T x hybrid compared with MoS 2 was observed. Abstract Developing highly efficient noble-metal-free electrocatalysts for hydrogen evolution reaction (HER) has attracted increasing attentions. Here, we report a simple strategy to synthesize the hierarchical "nanoroll" like MoS 2 /Ti 3 C 2 T x hybrid by combining liquid nitrogen-freezing and subsequent annealing. The quick freezing of the Ti 3 C 2 T x nanosheets and ammonium tetrathiomolybdate mixture causes a sudden change in the strain of Ti 3 C 2 T x , which leads to an interesting "nanoroll" like hierarchical structure. After annealing at H 2 /Ar atmosphere, vertically aligned molybdenum sulfide (MoS 2) crystallites are in situ formed in and on the nanoroll like Ti 3 C 2 T x. Notably, this hierarchical MoS 2 /Ti 3 C 2 T x hybrid exhibits excellent HER catalytic activity with a small onset overpotential of 30 mV, and a more than 25-fold increase in the exchange current density compared with MoS 2 was observed. [ABSTRACT FROM AUTHOR]