A DFT-D2 study on the adsorption of phosgene derivatives and chloromethyl chloroformate on pristine and Fe4-decorated graphene.

Phosgene derivatives and chloromethyl chloroformate are chlorinated organic compounds, which are toxic in nature and are used as chemical warfare agents and for the synthesis of other organic compounds. In this work, the different modes of adsorption of these toxic molecules on pristine graphene and Fe4-decorated graphene have been studied. It has been found that physisorption of these adsorbates occurs on pristine graphene, but when graphene is decorated with a Fe4-cluster, dissociative adsorption takes place and the adsorption energy and charge transfer increase. After Fe4-cluster decoration, the surface exhibits magnetic character and its band gap decreases. The magnetic properties of the surface, before and after adsorption, have been studied using density of states (DOS)/partial density of states (PDOS) and electron density difference plots and it is found that the band gap increases after adsorption of the adsorbates.