Effects of element doping and H2O presence on CO2 adsorption using hexagonal boron nitride

The characteristics of CO2 adsorbing on hexagonal boron nitride (h-BN) under various conditions are key to its application in industries. In this study, h-BN is selected as the adsorbent for CO2 adsorption and carbon/nitrogen (C/N) is the doping element. By means of density functional theory (DFT) calculations, adsorption structures, adsorption energies, distribution of electron clouds, transition state (TS) processes (free state adsorption state) and effects of H2O are used to explain adsorption mechanisms of CO2 on pure/doped h-BN. According to calculation results, with doping of C/N, the delocalized 't bond of h-BN is transformed and then CO2 adsorption on the specific site is enhanced. In the meantime, this study also reveals that h-BN should be treated as the tertiary amine in a way because H2O presence could obviously facilitate CO2 adsorption on pure/doped h-BN, consistent with existing studies. What is more, the study uncovers that the TS energy barrier of CO2 adsorption is another factor that affects adsorption strength. It is found that doping of C/N and H2O presence could reduce adsorption energy barriers and facilitate CO2 adsorption. The research results could provide valuable information about exploiting h-BN for massive CO2 adsorption in industrial situations.

Automated summary

In this study, the adsorption mechanisms of CO2 on pure/doped h-BN were investigated using DFT calculations, revealing that doping of C/N and presence of H2O can enhance CO2 adsorption. It was also found that the TS energy barrier of CO2 adsorption is a crucial factor affecting adsorption strength. These research results provide valuable information for exploiting h-BN for massive CO2 adsorption in industrial situations.