Thermostable 1T-MoS₂ Nanosheets Achieved by Spontaneous Intercalation of Cu Single Atoms at Room Temperature and Their Enhanced HER Performance

A simple strategy to fabricate Cu single atoms (SAs) layer-intercalated MoS₂ only by stirring Cu metals with MoS₂ nanosheets solution at room temperature is reported. An ultra-high concentration (Cu: Mo = 98 at%) of Cu SAs is achieved and the intercalated Cu atoms strongly enhance the stability of the thermodynamically unstable 1T-phase dominant MoS₂. Notably, the as-synthesized MoS₂/Cu-SAs exhibit a surprisingly high proportion of the metallic phase (64%) even after annealing at 800 °C in 5% H₂/Ar foaming gas, indicating extraordinary thermostability of the Cu intercalated 1 T-MoS₂. In addition to, the as-prepared MoS₂/SAs exhibit outstanding catalytic performance owing to the improved electrical conductivity and the highly active unsaturated Cu SAs. This strategy is confirmed as a universal method for producing SAs of other metals and other 2D nanosheets can also be used as the host for SAs intercalation other than MoS₂. This study may provide an effective strategy to fabricate facile and low-cost SAs catalysts.