Boron-rich enhanced ambient CO2 capture and storage of boron–carbon–nitride hybrid nanotubes

Abstract

Increasing carbon dioxide (CO₂) emissions as the most challenging greenhouse gas is considered as a major cause of global warming and ocean acidification. Different strategies against anthropogenic emissions of CO₂ have been applied to capture and reduce the CO₂ effect on the atmosphere. To this end, we study the adsorption of CO₂ on boron-rich structures of boron–carbon–nitride (BCN) hybrid nanotubes by the implementation of an ab initio approach based on density functional theory (DFT). Three different boron-rich BC₂N, BC₄N, and parallel BCN (p-BCN) nanotubes are investigated as hosts for the capture and sequestration of CO₂. The analysis of calculations shows that the boron-rich BC₄N nanotube adsorbs CO₂ physically, while in the boron-rich BC₂N and p-BCN nanotubes, both chemisorption and physisorption occurred. In the chemisorption process, a linear CO₂ molecule is bent over, and a new bond is formed between oxygen and boron antisite (B_N) in boron-rich nanotubes due to electron back donation between CO₂ and nanotubes as a result of orbital mixing of oxygen and boron atoms. Moreover, our findings show that the sensitivity factor (SF) and adsorption energy for boron-rich BC₂N nanotubes are higher than those of other hybrid nanotubes and CO₂ free energy at room temperature. Elaborating on the stability and recycling of host material challenges suggests that the boron-rich hybrid nanotubes could be a good candidate for capturing CO₂ under ambient conditions.