Ultrastable In-Plane 1T-2H MoS2 Heterostructures for Enhanced Hydrogen Evolution Reaction

Metallic 1T MoS2 is highly desirable for catalyzing electrochemical hydrogen production from water owing to its high electrical conductivity. However, stable 1T MoS2 is difficult to be produced in large-scale by either common chemical or physical approaches. Here, ultrastable in-plane 1T-2H MoS2 heterostructures are achieved via a simple one-pot annealing treatment of 2H MoS2 bulk under a mixture gas of Ar and phosphorous vapor, where phosphorus cannot only occupy the interspace of MoS2 bulk, resulting in the expansion of MoS2, but also embed into the lattice of MoS2, inducing the partial phase transition from 2H to 1T phases of MoS2. Benefiting from its significantly improved electrical conductivity, highly exposed active sites, and hydrophily property, in-plane 1T-2H MoS2 heterostructures exhibit largely improved electrocatalytic properties for hydrogen evolution reaction (HER) in alkaline electrolytes.