Hole-matrixed carbonylated graphene: Synthesis, properties, and highly-selective ammonia gas sensing

Here, the synthesis of holey carbonylated (C-ny) graphene derivative and its application for gas sensing is demonstrated. The carbonylation of graphene oxide leads to the 3-fold increase in the concentration of carbonyl groups' up to 9 at.% with a substantial elimination of other oxygen functionalities. Such a chemical modification is accompanied by the perforation of the graphene layer with the appearance of matrices of nanoscale holes, leading to corrugation of the layer and its sectioning into localized domains of the π-conjugated network. Combined with the predominant presence of carbonyls, granting the specificity in gas molecules adsorption, these features result in the enhanced gas sensing properties of C-ny graphene at room temperature with a selective response to NH3. Opposite chemiresistive response towards ammonia when compared to other analytes, such as ethanol, acetone, CO2, is demonstrated for the C-ny graphene layer both in humid and dry air background. Moreover, a selective discrimination of all of the studied analytes is further approached by employing a vector signal generated by C-ny multielectrode chip. Comparing the experimental results with the calculations performed in framework of density functional theory, we clarify the effect of partial charge transfer caused by water and ammonia adsorption on the chemiresistive response.