Electrochemical And Magnetical Performance Of MoS₂-Based Materials

In this thesis, we study the electrochemical and magnetical performance of MoS₂- based two dimensional materials, we focused on two parts, the hydrogen evolution reaction of MoS₂ NS/carbon cloth as a 3D integrated electrode, and the room-temperature ferromagnetism in Co doped MoS₂ sheets.Firstly, we reportd a facile approach to the low-temperature hydrothermal fabrication of a 2H-MoS₂ nanosheets array on carbon cloth?2H-MoS₂ NS/CC?. Li-intercalation was used to prepare 1T-MoS₂ sheets from pristine 2H-MoS₂ NS/CC. X-ray photoelectron spectroscopy?XPS? and Raman spectra confirmed the local phase transitions from trigonal prismatic?2H-MoS₂? into octahedrally coordinated Mo?1T-MoS₂?. Then, we investigated the HER activity of Li-MoS₂ NS/CC as a 3D integrated electrode in 0.5 M H2SO4 at room temperature using a typical three-electrode setup. The results exhibited excellent catalytic activity in acidic media. The Li-MoS₂ NS/CC 3D Electrode needs overpotentials of 97 and 132 mV to approach 10 and 100 mA cm-2, respectively, which are smaller than the previously reported values. This performance of the Li-MoS₂ NS/CC electrode suggests that it may hold great promise for practical applications.In the second part, via the hydrothermal method, we synthesized MoS₂ nanosheets with varying Co dopant concentrations of 0%, 3% and 7%, using cobaltous acetate as a promoter, and marked as A, B, and C, respectively. We found that the thickness and flatness of the nanosheets increased with the increase of the co dopant concentrations. Meanwhile, the BET Surface Areas of samples?A, B, and C? decreased with the increase of the Co dopant concentrations. Optical absorption spectroscopy showed that, compared to sample A, the A1 and B1 excitons of samples B and C were 10 and 30 meV redshifted, respectively. Then, we performed magnetization measurement to investigate the effect of co-doping; the unique result implied that the values of the magnetic moment decreased with the increase of the Co dopant concentrations. We performed DFT computations to address the above magnetic result. The computational result indicated that the value of the magnetic moment decreased with the increase of the Co dopant concentrations, which is in agreement with results of the experiments described above.