DFT study on the adsorption of p-nitrophenol over vacancy and Pt-doped graphene sheets

The frequent and widespread use of p-nitrophenol at commercial scale is giving rise to several health hazards among living beings and damage to the ecosystem. In this work, the adsorption of para-nitrophenol (p-NP) on pristine/vacancy-graphene and Pt-4-cluster doped graphene systems are investigated using density functional theory (DFT). Two modes of adsorption have been considered: perpendicular and parallel. While adsorption of p-NP on the pristine graphene substrate is unfavorable, it is found that the adsorption capacity of graphene can be significantly increased by creating defects and by doping with Pt-clusters. Different electronic properties, like partial density of states (PDOS), reveal that on doping with a Pt-cluster, the band gap of the surface decreases and the substrates start showing magnetic character. Electron density difference plots give insights into the adsorption behavior of p-NP.