Metallic 1T MoS₂ nanosheets are highly desirable for application in catalysis, energy storage, and energy production due to their high electrical conductivity and abundant active sites. Here, this work presents a new strategy to prepare 1T-phase MoS₂ nanosheets through light exfoliation and chemical doping by femtosecond laser ablation of bulk 2H-phase MoS₂ crystals in a Fe ion solution. Femtosecond laser induces the light exfoliation of MoS₂ with the breakage of chemical bonds and increased chemical activity of MoS₂, which is conducive to the chemical adsorption and doping of Fe atoms on MoS₂ and hence to the reversion of the original 2H phase to a 1T phase, finally obtaining 1T-phase MoS₂ nanosheets. The prepared MoS₂ nanosheets have a uniform shape and size, high crystallinity, coexisting 1T and 2H phases, highly active S, and are chemically combined with Fe atoms. Moreover, the prepared phase-reversed MoS₂ nanosheets can be applied as electrocatalysts for the electrochemical hydrogen evolution reaction (HER) and exhibit a considerable enhancement of the HER catalytic activity compared with the common 2H-phase and ion-intercalated MoS₂ nanosheets, thus proving their huge potential for catalysis and energy applications.

中文翻译：

---

通过飞秒激光剥落和化学掺杂制备的反相MoS ₂纳米片

金属1T MoS ₂纳米片由于其高电导率和丰富的活性位点，非常适合用于催化，能量存储和能量生产。在这里，这项工作提出了一种新的策略，即通过光剥落和飞秒激光烧蚀Fe离子溶液中的2H相MoS ₂本体晶体，通过光剥落和化学掺杂来制备1T相MoS ₂纳米片。飞秒激光通过化学键的断裂和MoS _2的化学活性的增强引起MoS ₂的光剥落，这有利于Fe原子在MoS ₂上的化学吸附和掺杂。因此，将原始2H相还原为1T相，最终获得1T相MoS ₂纳米片。制备的MoS ₂纳米片具有均匀的形状和大小，高结晶度，1T和2H相共存，高活性S，并与Fe原子化学结合。此外，与普通的2H相和离子嵌入的MoS ₂纳米片相比，制备的相转化的MoS ₂纳米片可以用作电化学放氢反应（HER）的电催化剂，并显示出HER催化活性的显着提高。证明了它们在催化和能源应用方面的巨大潜力。