Graphene is a promising candidate for chemical vapor sensing. We prepared graphene sheets from highly oriented pyrolytic graphite through mechanical cleavage in order to investigate their responses to NH 3 and NO 2 as electron donors and acceptors, respectively. We investigated how the geometric characteristics of graphene, such as length-to-width (L/w) ratio and number of layers, affect chemical sensing properties at room temperature and ambient atmosphere. In this study, the L/w ratio of an individual graphene sheet, which is related to graphene conductivity, dominated the NH 3 sensing characteristics, while the number of graphene layers had no significant effect. We also studied the effects of various thermal treatments on graphene sensitivity and recovery time in an ambient atmosphere. This study confirms the effects of geometry, operation temperature and gas concentration on the NH 3 and NO 2 sensing performances of graphene.
Bibliographical noteFunding Information:
Sukju Hwang and Juhwan Lim have equally contributed to this work. This work was partially supported by Samsung Advanced Institute of Technology (2010-8-2239), the Priority Research Centers Program (2009-0093823), the Pioneer Research Center Program (2010-0019313), and the Basic Science Research Program (2011-8-0856) through the National Research Foundation of Korea (NRF) funded by the Ministry of Education, Science and Technology (MEST) of the Korean government.
All Science Journal Classification (ASJC) codes
- Materials Science(all)
- Physics and Astronomy(all)