The influence of oxygen functional groups on gas-sensing properties of reduced graphene oxide (rGO) at room temperature

Abstract

Three methods were used to prepare reduced graphene oxide (rGO) with various ratios of oxygen functional groups, such as –OOH, –OH and CO, to study their effects on the NO₂ sensing properties at room temperature. It was found that the percentages of oxygen-containing species such as –OH in the rGO nanosheet, significantly affected the sensitivity of rGO to NO₂ at room temperature. The –OH species can promote the sensitivity and also the recovery ability with respect to NO₂. This may be because –OH has a greater attraction to NO₂ and obtains electrons from it, whereas the separation of NO₂ from –OH is also slightly easier, enabling a better recovery compared to other oxygen functional groups such as –OOH and CO.