Besides, calculation results indicate that adsorption of nonmetal elements on the surface of WS2 nanosheets can induce a local magnetic moment [19]. In an experimental study, Matte et al. fabricated WS2 nanosheets by hydrothermal method and revealed their ferromagnetism, which was considered to be related to the edges and defects [20]. Developed liquid exfoliation process is considered to be an effective pathway to prepare the ultrathin two-dimensional nanosheets of intrinsically layered structural materials with high quality [21]. In this paper, the

ultrathin WS2 nanosheets were gotten by exfoliating bulk WS2 in N,N-dimethylformamide MM-102 order (DMF, 100 mL) solution as in our previous report

[22], and we studied the magnetic properties of WS2 nanosheets experimentally from 300 K down to 10 K. Results indicate that the fabricated WS2 nanosheets show clear room-temperature ferromagnetism which possibly originates from the existence of zigzag edges or defects with associated magnetism at grain boundaries. Methods WS2 nanosheets were prepared through exfoliating of bulk WS2. In a typical synthesis progress, 0.5 g of WS2 powders was sonicated in N, N-Dimethylformamide (DMF, 100 mL) to disperse the powder. After precipitation, the black dispersion was centrifuged at 2000 rpm for about 20 minutes to remove the residual large-size WS2 powders. Then, the remainder solution was centrifuged at 10000 rpm for 1 h to obtain the black products. To Selleck MK-0457 remove the excess surfactant, the samples were repeatedly washed with ethanol and centrifuged. Finally, the samples were dried at 60°C in vacuum condition. Results and discussion Figure 1a shows the schematic illustration of liquid exfoliation process from bulk WS2 to ultrathin nanosheets. When ultrasonication was carried out in the DMF solution, Dolutegravir in vivo the WS2 bulk materials swelled with the insertion of DMF molecules into the layers, which can then be easily exfoliated into the nearly transparent ultrathin nanosheets. In the absence

of any high-temperature treatment or BVD-523 mouse oxidation process, the exfoliated nanosheets will retain the same crystal structure of the bulk materials. Typical X-ray diffraction (XRD, X’ Pert PRO Philips with Cu Kα radiation; Philips, Anting, Shanghai, China) patterns of the WS2 bulk and nanosheets are reported in Figure 1b. During the XRD test, the exfoliated WS2 nanosheets were collected together onto the glass substrate. That is to say, the XRD result can be gotten just as the other powder sample in our case. It can be seen that all the diffractions for the exfoliated nanosheets are corresponding to the hexagonal phase of WS2 (JCPDS card no. 85-1068) and as comparable to the bulk form. The dominated (002) diffraction peak indicates the growth of WS2 along the c-axis direction.