Electronic Properties and CO2-Selective Adsorption of (NiB)(n) (n=1 similar to 10) Clusters: A Density Functional Theory Study

In this study, we investigated the electronic properties and selective adsorption for CO2 of nickel boride clusters (NiB)n, (n = 1 similar to 10) using the first principles method. We optimized the structures of the clusters and analyzed their stability based on binding energy per atom. It was observed that (NiB) n clusters adopt 3D geometries from n = 4, which were more stable compared to the plane clusters. The vertical electron affinity, vertical ionization energy, chemical potential, and highest occupied molecular orbital (HOMO)-lowest unoccupied molecular orbital (LUMO) gap were calculated. Our results revealed that (NiB) 6 and (NiB)10, with high chemical potential, exhibit a higher affinity for CO2 adsorption due to a charge delivery channel that forms along the Ni!B!CO2 path. Notably, (NiB) 10 demonstrated a more practical CO2 desorption temperature, as well as a broader window for the selective adsorption of CO2 over N-2. The density of states analysis showed that the enhanced CO2 adsorption on (NiB) 10 can be attributed to the synergistic effect between Ni and B, which provides more active sites for CO2 adsorption and promotes the electron transfer from the surface to the CO2 molecule. Our theoretical results imply that (NiB) 10 should be a promising candidate for CO2 capture.

Automated summary

In this study, the electronic properties and selective adsorption for CO2 of nickel boride clusters (NiB)n, (n = 1 to 10), were investigated using the first principles method. The optimized structures and stability of the clusters were analyzed based on binding energy per atom. It was found that 3D geometries were more stable for (NiB) n clusters from n = 4, compared to plane clusters. Various electronic properties were calculated, including vertical electron affinity, vertical ionization energy, chemical potential, and highest occupied molecular orbital (HOMO)-lowest unoccupied molecular orbital (LUMO) gap. The results revealed that (NiB)6 and (NiB)10 exhibited a higher affinity for CO2 adsorption due to the formation of a charge delivery channel along the Ni!B!CO2 path, with (NiB)10 showing more practical CO2 desorption temperature and a broader window for selective adsorption of CO2 over N-2. Density of states analysis indicated that the enhanced CO2 adsorption on (NiB)10 can be attributed to the synergistic effect between Ni and B, providing more active sites for CO2 adsorption and promoting electron transfer from the surface to the CO2 molecule. Therefore, (NiB)10 is considered a promising candidate for CO2 capture.