Adsorption of formaldehyde molecule on the pristine and transition metal doped graphene: First-principles study

Abstract

The adsorption of H2CO molecule on pristine and transition metal (Ti and V) doped graphene samples were investigated via a first-principles approach based on density functional theory. The most stable adsorption geometry, energy and charge transfer of H2CO molecule on pristine and doped graphene are discussed respectively. We have found that Ti and V dopant atoms can significantly enhance the interaction between H2CO molecule and graphene. The calculated net electron transfers, electronic density difference images and densities of states give the evidence that the H2CO molecules stay on Ti (orV) – doped graphene by chemisorption. After H2CO adsorption, there are significant changes in electronic structure near the Fermi level, for both two systems of Ti and V doped graphene. This indicates distinct changes of electron transport properties. We have also found that H2CO molecule has a larger absorption energy on V-doped graphene (1.939eV) compared with Ti-doped graphene (1.120eV). It is shown that the Ti-doped graphene has enough binding energy, adequate changes in electronic structure and reasonable short recovery time 10−3s, making it a promising candidate for detecting formaldehyde gas.