Warped C80H30 nanographene as a chemical sensor for CO gas: DFT studies

In 2013, synthesis of a grossly warped nanographene (C80H30, NG) which was reported in Nature Chemistry opens a new avenue in carbonaceous nanomaterial research. Here we investigated the chemical reactivity and electronic sensitivity of this NG to carbon monoxide (CO) gas, using density functional theory calculations. It was found that the CO molecule prefers to be added to a C-C bond at the center of NG similarly to the [2+2] addition. The calculated adsorption energy which is about −10.92 kJ/mol is accompanied by a natural bond orbitals (NBO) charge transfer of 0.21 e from the NG to the CO molecule. Unlike the graphene, the electronic properties of NG are significantly affected by the CO adsorption. After the CO adsorption, the electrical conductivity of the NG is considerably increased which can be converted to an electrical signal. Thus, it is concluded that the NG may be a potential compound for the CO chemical sensors for which the pristine graphene is not appropriate. We demonstrated that by increasing the concentration of the CO molecules the electrical conductivity is increased more. Also, a short recovery time of about 83 ps is predicted for NG sensor.