A Novel Interconnected Structure of Graphene-Carbon Nanotubes for the Application of Methane Adsorption

• Published in: IEEE sensors journal Vol. 18; no. 4; pp. 1555 - 1561
• Main Authors: Yang, Ning, Yang, Daoguo, Chen, Liangbiao, Liu, Dongjing, Cai, Miao, Fan, Xuejun
• Format: Journal Article
• Language: English
• Published: IEEE 15.02.2018
• Subjects: Adsorption; Carbon; Discrete Fourier transforms; doping; first-principles theory; Graphene; Junctions; junctions of G-CNTs; Methane; methane adsorption capacity; molecular dynamics; Sensors
• ISSN: 1530-437X; 1558-1748
• DOI: 10.1109/JSEN.2017.2783040

In this paper, the methane adsorption properties of a new 3-D structure, graphene connected with carbon nanotubes (G-CNTs) was investigated, which has a great significance to the development of methane sensors. The junctions of the armchair graphene connected with (6, 0) and (4, 4) CNTs (arm-60 and arm-44) were selected. First, the adsorption energy on different sites was analyzed via first-principles theory to find out the best methane adsorption site. The results showed that the adsorption energy of arm-44 was a little bigger than that of arm-60. Moreover, the adsorption energy was bigger, when the adsorption site was closer to the junction. Second, the adsorption capacity of various gases (H 2 , O 2 , CO, CO 2 , NO 2 , and CH 4 ) was compared via molecular dynamics. The methane adsorption capacity of arm-60 was found to be the biggest. As the fugacity is increased, the methane adsorption capacity increased gradually. Oppositely, the adsorption capacity was inversely proportional to the temperature. Finally, the effects of Al, P, Si, N, and B doping on methane adsorption capacity were reported. The B doping had the best power to improve the methane adsorption capacity, whereas the N and Si doping were unfavorable for the methane adsorption capacity.