Molybdenum disulfide as a highly efficient adsorbent for non-polar gases
Molybdenum disulfide as a highly efficient adsorbent for non-polar gases
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二硫化钼作为非极性气体的高效吸附剂
DOI：
10.1039/c5cp00161g
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发表时间：
2015
影响因子：
3.3
通讯作者：
Li Youyong
中科院分区：
文献类型：
--
作者：
Yu Ningning;Wang Lu;Li Min;Sun Xiaotian;Hou Tingjun;Li Youyong
二硫化钼（MoS2）是一种类石墨烯二维材料，因其独特的性质和在电子学和传感器领域的潜在应用而引起人们极大的兴趣。本文通过第一性原理计算和巨正则蒙特卡罗（GCMC）模拟来表明MoS 2层能够有效吸收非极性气体。与目前流行的气体吸附剂（金属有机骨架和碳基材料）相比，MoS2具有额外的优点，包括大的表面积与体积比和可调性能。系统地研究了非极性气体[CO2和CH4]在有空位和无空位的MoS2层上的吸附。理想的MoS2对CO2和CH4分子几乎没有吸附，而具有单S空位和双S空位的MoS2对CO2和CH4分子具有很好的吸附能力。CO2的吸附能分别为65 kJ mol-1，CH 4的吸附能分别为47 kJ mol-1（货车德瓦尔斯-D2）。CO_2（或CH_4）分子的p轨道与Mo原子的d轨道之间存在轨道耦合。GCMC模拟结果表明，在80 bar的压力下，室温下单S空位的MoS2可以吸收42.1wt%的CO2和37.6wt%的CH4。结果表明，缺陷单层二硫化钼对非极性气体是一种高效的吸收剂。
Molybdenum disulfide (MoS2), a kind of graphene-like, two-dimensional material, has attracted great interest because of its unique properties and potential applications in electronics and sensors. In this paper, first-principle calculations and grand canonical Monte Carlo (GCMC) simulations are performed and used to show that the MoS2 layer is efficient at absorbing non-polar gases. Compared with the popular gas sorbents (metal organic frameworks and carbon-based materials), MoS2 has additional advantages, including large surface to volume ratio and tunable properties. The non-polar gas [carbon dioxide (CO2) and methane (CH4)] adsorption on the MoS2 layer with and without vacancies has been systematically studied. The perfect MoS2 shows little or no adsorption for CO2 and CH4 molecules, but the MoS2 with a single S vacancy and double S vacancies exhibits an excellent adsorption ability for CO2 and CH4 gases. The adsorption energies were 65 kJ mol−1 for CO2 and 47 kJ mol−1 for CH4 (van der Waals-D2), respectively. An orbital coupling between the p orbital of the CO2 (or CH4) molecule and the d orbital of the Mo atom was observed. GCMC simulation results show that MoS2 with a single S vacancy could absorb 42.1 wt% of CO2 and 37.6 wt% of CH4 under a pressure of 80 bar at room temperature. The results given in this paper indicate that monolayer MoS2 with defects is a highly efficient absorbent for non-polar gases.