Density functional studies of small gases adsorbed on the ZnO sodalite-like cage and its adsorption abilities

The geometry optimizations of ZnO sodalite-like cage (ZnOSL), Zn12O12 cluster and its adsorption configuration with diatomic (H2, N2, O2, CO, NO), triatomic (CO2, N2O, NO2, H2O, SO2) and tetraatomic (NH3) gases were carried out using density functional theory method. Adsorption energies of these gases on ZnOSL were obtained at the B3LYP/Lanl2DZ level of theory. The strongest adsorption energies of diatomic and triatomic gases on ZnOSL at ML = 0.082 are ΔEads(O2) = −14.09 and ΔEads(SO2) = −35.06 kcal/mol, respectively. The adsorption energy of ammonia adsorbed on ZnOSL at ML = 0.082 is ΔEads(NH3) = −25.41 kcal/mol. Energy gaps and density of states plots for ZnOSL and their gases adsorption configurations are reported. All the adsorption results computed by the B3LYP/Lanl2DZ method were validated by comparison with their corresponding results computed by the B97D/Lanl2DZ method.