This study addressed the nano-mechanism of CO2 capture by Al-doped, B-doped and N-doped single-walled silicon carbide nanotubes (SWSiCNTs) using the prominent density functional theory. The results showed absolute interactions between CO2 and B- and N- impurity atoms of the SWSiCNT surface with the highest adsorption energy of −1.85 eV and −1.83 eV respectively. Analysis of the binding energy of CO2 to Al-doped SWSiCNT revealed that chemisorption between them is stronger than B-doped and N-doped SWSiCNTs. Results from optical adsorption spectra revealed that both B-and N-doped systems adsorb CO2 in the visible region of the electromagnetic spectrum while B-doped SiCNT shows the highest adsorption. This study recommends B- and N-doped SiCNTs as candidates for CO2 capture and storage with higher efficiency by B-doped SiCNT, while the performance of the Al-doped system was underscored.