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利用低能N+(0.5keV)离子轻微轰击2H-MoS2(0001)清洁表面,从UPS(HeⅠ,HeⅡ)得到d电子峰向EF移动,价带顶出现明显的“肩膀”或带尾,它随轰击时间的增加而增强,同时使d(z2)带变宽。UPS的结果表明,这种表面在室温下有明显的O2吸附活性,O2吸附后这个肩膀明显下降。结合XPS,AES和LEED的研究,我们认为这个“肩膀”态与次表面原子层的Mo原子的d电子的暴露和最外表面原子层s原子空位缺陷的产生有关。这些新的表面电子态与加氢脱硫(HDS)催化活性中心有密切的关系。UPS, XPS, AES and LEED have been applied to study the samples prepared by low energy N+(0.5keV) sputtering slightly the clean cleaved surface of 2H-MoS2 (0001). From UPS (He Ⅰ, He II) spectra the shifts of EF of d band were observed. A "shoulder" or a band tail above the top of the d(z2) band raised with the time of ion bombardment so that the shape of the d(z2) band became broad. The new state showed chemically active to O2 exposure at room temperature. We propose that these shoulder states arise from the new unsaturate bonding d-electrons of Mo atoms around the vacancies of S at the outermost layer of the surface. This new surface electronic state may be correlated with the catalysis active site for hydrodesulfurization (HDS).
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