Hybrid Modeling of Molecular Sensing and Catalysis in Low-dimensional Nanomaterials

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• 作者：Artem Baskin^a ; ^b ; Petr Krá ; l^b ; ^c ; ^{pkral@uic.edu" class="auth_mail" title="E-mail the corresponding author}
• 关键词：grain boundaries ; transport channels ; molybdenum disulphide ; carbon dioxyde reduction
• 刊名：Materials Today: Proceedings
• 出版年：2016
• 出版时间：2016
• 年：2016
• 卷：3
• 期：2
• 页码：396-410
• 全文大小：1285 K

文摘

We use hybrid quantum and classical modeling to describe recently observed molecular sensing at graphene grain boundaries and electrochemical reduction of carbon dioxide (CO₂) on molybdenum disulphide (MoS₂) flakes. In the sensing studies, classical and quantum molecular dynamics simulations are used to relax graphene with grain boundaries deposited on amorphous SiO₂. Electronic structure calculations show how this graphene is locally doped by the substrate and adsorbed molecules, while electronic transport modelling reveals that the doping can lead to synchronous opening and closing of local electron transport channels, resulting in a very large observed sensitivity. In the catalysis studies, electronic structure calculations combined with ab initio molecular dynamics uncover that the metallic character and high d-electron density of molybdenum-terminated MoS₂ edges and EMIM-ion delivery are responsible for the observed superior CO₂ reduction performance, with a high current density and low ∼54 mV overpotential. The described mechanisms open up new pathways for the design of nanometer-scale highly sensitive chemical detectors and the development of inexpensive systems of CO₂ conversion to energy-rich products. These studies illustrate how hybrid modeling techniques can explain complex transport phenomena in nanostructures.