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. Single atom anchored in 2D nanosheets are successfully fabricated by simply stirring metals with nanosheets in solution at room temperature. The maximum doping concentration is close to 98% and the Cu single atom doped MoS2 shows 1T phase, which can be stabilized as high as 800 °C and demonstrates strongly enhanced hydrogen evolution reaction.