通过电催化将水分解可大量制备高纯度氢气,这一过程需要高效能低成本的电催化剂材料.二硫化钼价格低廉、资源丰富,且具有类似贵金属铂的氢吸附自由能,是一种潜在的高效制氢电催化剂.然而其仍面临着析氢过电位偏高、稳定性差、难以批量制备、在碱性环境下催化析氢活性较低等问题,限制了其实际应用.目前,大量文献证实制造缺陷是一种有效的优化二硫化钼电催化活性的方法.本文通过球磨还原法制备了一种富含缺陷的二硫化钼析氢反应电催化剂.这种新型的富缺陷二硫化钼催化剂在酸碱性条件下都显示出较高的催化活性,在酸性条件下,过电位为176 mV时其电流密度可达10 mA cm^(-2);在碱性条件下,过电位为189 mV时其电流密度可达10 mA cm^(-2),超过了大部分报道的析氢反应电催化剂.此外,富缺陷二硫化钼材料显示出较小的塔菲尔斜率和良好的电化学稳定性,进一步证实了析氢反应催化活性的增强.这种通过球磨还原制造缺陷的思路为未来催化剂的设计与性能优化开辟了一条新的道路,且该方法简单,适于大规模的工业生产.
The coupling interaction between an individual optical emitter and the propagating surface plasmon polaritons in a graphene microribbon （GMR） waveguide is investigated by numerical calculations, where the emitter is situated above the GMR or in the same plane of the GMR, The results reveal a multimode coupling mechanism for the strong interaction between the emitter and the propagating plasmonic waves in graphene. When the emitter is situated in the same plane of the GMR, the decay rate from the emitter to the surface plasmon polaritons increases more than 10 times compared with that in the case with the emitter above the GMR.
Recently, two-dimensional (2D) layered semiconducting materials have been considered as promising channel materials to construct aggressively-scaled transistors owing to their excellent electrostatics and remained high carrier mobility even at atomic thickness (1,2)Among all of the emerging 2D semiconductors.
