A DFT and MD study of reactive, H2 adsorption and optoelectronic properties of graphane nanoparticles – An influence of boron doping

Abstract

Structural, reactive, H2 adsorption and charge transfer properties of graphane nanoparticles modified with boron atom have been investigated using the combination of density functional theory (DFT) calculations and molecular dynamics (MD) simulations. Studies of reactivity encompassed calculations of molecular electrostatic potential (MEP) and average local ionization energy (ALIE) descriptors. It has been demonstrated by these quantum-molecular descriptors that reactivity of studied systems significantly increases in the near vicinity of boron dopants. Adsorption properties of studied graphane and its derivative nanoparticles have been performed towards the hydrogen molecules, in order to assess the potential of studied structures in the area of clean energy sources. Results indicate that introduction of boron atoms greatly improves the H2 binding energies. Symmetry-adapted perturbation theory (SAPT) calculations enabled us to decompose the interaction energy to physical contributions and to better understand the influence of boron atoms to the H2 adsorption properties. Charge transfer rates and charge mobilities have been calculated according to Marcus semi-empiric approach. Optoelectronic properties of studied nanostructures have been compared to that of pentacene molecule, in order to further draw attention to their potential for practical applications in materials science area. The influence of size of the graphane nanoparticles was also taken into account and calculations show that both reorganization energies and ΔE(S1−T1) parameter decrease with the increase in size. In case of the largest pristine graphane nanoparticle considered in this work, the electron reorganization energy is lower than in case of the pentacene, while ΔE(S1−T1) parameter has very low value of just 0.05 eV.