Abstract In the present theoretical study, the effect of methane adsorption on the electronic properties of titanium (Ti)-decorated γ-graphyne (γ-GY) is investigated. To this end, the dispersion-corrected density functional theory (DFT-D2) is employed to explicitly include the van der Waals interactions (vdW) in the computations. The results show that the methane is physisorbed on the γ‒GY owing to the low binding energy and relatively long adsorption distance. According to our calculations, Ti atom is chemically bound to four sp carbon atoms with the binding energy of −4.960 eV (per supercell) and provide an appropriate adsorption site for reducing gas molecule such as methane. We also observe that the methane molecule chemisorbed on the Ti-decorated γ-GY with the binding energy of −0.594 eV per supercell. Moreover, upon methane adsorption, the electronic bandgap of Ti-decorated γ-GY reduces about 0.051 eV. Our results reveal that Ti-decorated γ-GY has excellent sensing efficiency for CH4 gas with high selectivity and fast recovery time. Therefore, the present work encourages the growing use of Ti-decorated γ-GY for the development of thermopower-based, resistive-based, or quartz crystal microbalances-based methane sensors.

中文翻译：

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基于 Ti 装饰 2D γ-石墨烯的新型高性能甲烷传感器：色散校正 DFT 洞察

摘要 在目前的理论研究中，研究了甲烷吸附对钛 (Ti) 修饰的 γ-石墨烯 (γ-GY) 电子性质的影响。为此，采用色散校正密度泛函理论 (DFT-D2) 在计算中明确包含范德华相互作用 (vdW)。结果表明，甲烷由于较低的结合能和较长的吸附距离而被物理吸附在γ-GY上。根据我们的计算，Ti 原子与四个 sp 碳原子化学结合，结合能为 -4.960 eV（每个超晶胞），并为还原甲烷等气体分子提供了合适的吸附位点。我们还观察到甲烷分子化学吸附在 Ti 修饰的 γ-GY 上，每个超级电池的结合能为 -0.594 eV。此外，在甲烷吸附时，Ti修饰的γ-GY的电子带隙降低了约0.051 eV。我们的结果表明，Ti 修饰的 γ-GY 对 CH4 气体具有出色的传感效率，具有高选择性和快速恢复时间。因此，目前的工作鼓励越来越多地使用 Ti 装饰的 γ-GY 来开发基于热电、电阻或石英晶体微量天平的甲烷传感器。