Ultrasonic-Assisted Exfoliation Bulk-Phase of MoS2 with Chitosan/Acetic Acid Solution

As a transition metal dichalcogenides (TMDCs), molybdenum disulfide (MoS 2 ) comprises individual sheets stacked into a bulk-phase structure. Compared with bulk-phase MoS 2 , the few-layer MoS 2 presents a two-dimensional nanostructure similar to graphene, which has the advantages of large specific surface area and many unsaturated vacancies in the edge layer and has broad application prospects in the fields of photoelectricity and catalysis. Here, a simple and practical method of exfoliating bulk-phase MoS 2 is proposed. The bulk-phase MoS 2 was sonicated using chitosan/acetic acid (CS/HAc) solution to obtain oligomeric MoS 2 . The raw materials used in this method have good biocompatibility, the preparation process and operation are simple, and the pollution caused to the environment is small, which meets the green chemical standard. The method provides a new idea and way for the peeling treatment of other laminated materials. The results show that the stacking of (002) crystal plane of MoS 2 samples after treatment with CS/HAc solution is reduced and the crystalline phase is changed from polycrystalline to single-crystal structure, which has great potential for applications in optical and electrical fields.