First-principle investigation of CO adsorption on Pd-loaded VO2 monolayer

Using the first principle calculation based on density functional theory, the CO adsorption on pure VO2 monolayer and Pd-loaded VO2 monolayer (Pd/VO2) investigated systematically. The electronic structure and properties of the most energetic configuration are analyzed in terms of density of states and charge density difference. The results showed that the adsorption energy of CO on pure VO2 monolayer was −0.239 eV, and the length of V–O bond did not change obviously, which indicated physisorption. Further studies showed that the adsorption energy of CO adsorption on Pd/VO2 surface was −2.010 eV, and the length of V–O bond changed significantly, indicating that CO can be chemically adsorbed on Pd/VO2 surface. Finally, the calculation of optical properties showed that the absorption of visible light by CO adsorption on VO2 monolayer can be substantially improved due to the supported Pd atom. Therefore, the supported Pd atom can effectively improve the adsorption effect of pure VO2 monolayer, providing an promising method to promote the practical application of VO2 monolayer.