Exploring Non-adiabatic Molecular Dynamics Of Two-dimensional Materials

Since the discovery of graphene,many two-dimensional materials with unique electronic structures have been successfully prepared.The application of photocatalysis,energy storage,electrocatalysis and organic catalysis has attracted great attention.Due to their unique physical and chemical properties,photocatalysts based on two-dimensional materials are expected to provide excellent properties such as porous structure,high specific surface area,good crystallinity,high carrier mobility and abundant surface active sites.Non-adiabatic molecular dynamics of photoexcited carriers in two-dimensional materials plays an important role in photocatalysis and solar energy conversion.Non-adiabatic dynamics is usually related to excited carrier dynamics and photophysics,including charge and energy transfer,as well as carrier dissociation and charge recombination.Understanding the non-adiabatic molecular dynamics processes in two-dimensional materials is essential to provide an accurate description of carrier formation,evolution and decay.Based on non-adiabatic molecular dynamics,the study of interlayer charge transfer processes and electron-hole dynamics processes in two-dimensional materials facilitates the development ofphotocatalytic two-dimensional materials.In this article,we have studied the heterojunction of B4C3/g-C3N4 and single atom doped green phosphorus materials.The charge transfer process and photocatalytic properties of the two-dimensional materials have been studied by first-principles calculation and non-adiabatic molecular dynamics simulation.The main research contents of this paper are as follows:1.The dynamical process of photoexcited carriers at the interface of B4C3/g-C3N4 has been studied by non-adiabatic molecular dynamics simulation.It is found that the electrons in the g-C3N4 layer will be excited from the ground state to the excited state and transferred to the B4C3 layer under light irradiation.The main contribution to the charge transfer process is non-adiabatic rather than adiabatic processes caused by direct charge transitions or tunneling between different states.This behavior is effective in photogenerated charge separation and effectively inhibits hole-electron recombination.B4C3/g-C3N4 heterojunction has high charge transfer efficiency and carrier lifetime,which makes it promising for a wide range of applications in photocatalysis.2.The photocatalytic properties of green phosphorus and the electron-hole recombination process of single atom doped green phosphorus systems are studied by first-principles calculation and non-adiabatic molecular dynamics simulation.Through optical property studies,green phosphorus protocells as well as single atom doped green phosphorus systems have strong photoresponse properties in the visible region.The light absorption peaks of the pristine green phosphorus and the doped system are relatively close to each other,which indicates that doping with the same main group of elements does not affect the light absorption performance of the green phosphorus material.The carrier mobility of pristine green phosphorus is 4.88 × 104 cm2v-1s-1.The study of electron-hole recombination process shows that single atom doping reduces carrier lifetime.Owing to green phosphorus high carrier mobility and strong photoresponse,green phosphorus material is expected to be used in photocatalytic applications.