We investigated the relationship between defects in graphene and NO2 gas sensitivity of graphene-based gas sensors. Defects were introduced by hydrogen plasma or ultraviolet (UV)/ozone treatment. As the defect concentration increased, the sensitivity was enhanced, and sub-ppb level detection limit was achieved. UV irradiation was used for recovery at room temperature. However, defects generated by ozone treatment, like graphene oxide, were reduced back to graphene by UV irradiation, so the ozone-treated graphene sensor was not stable over time. In contrast, the response of the hydrogenated graphene sensor was very repeatable because defects generated by hydrogenation was stable enough not to be dehydrogenated by UV irradiation. These results demonstrate that the hydrogenated graphene sensor is a highly sensitive and stable NO2 sensor at room temperature.
Bibliographical noteFunding Information:
This work was financially supported by the Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Science, ICT and Future Planning (Grant Nos. 2016R1A2B3011980, 2014R1A2A1A11050290, and 2012R1A4A1029061).
All Science Journal Classification (ASJC) codes
- Physics and Astronomy (miscellaneous)