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 MoS 2 only by stirring Cu metals with MoS 2 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 MoS 2 . Notably, the as‐synthesized MoS 2 /Cu‐SAs exhibit a surprisingly high proportion of the metallic phase (64%) even after annealing at 800 °C in 5% H 2 /Ar foaming gas, indicating extraordinary thermostability of the Cu intercalated 1 T‐MoS 2 . In addition to, the as‐prepared MoS 2 /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 MoS 2 . This study may provide an effective strategy to fabricate facile and low‐cost SAs catalysts.