Zinc oxide nanoclusters and their potential application as <scp>CH<sub>4</sub></scp> and <scp>CO<sub>2</sub></scp> gas sensors: Insight from <scp>DFT</scp> and <scp>TD‐DFT</scp>
İskender Muz, Mustafa Kurban
Abstract
Abstract We have investigated the adsorption of CH 4 and CO 2 gases on zinc oxide nanoclusters (ZnO NCs) using density functional theory (DFT). It was found that the CH 4 tends to be physically adsorbed on the surface of all the ZnO NCs with adsorption energy in the range −11 to −14 kcal/mol. Even though, the CO 2 is favorably chemisorbed on the Zn 12 O 12 and Zn 15 O 15 NCs, with adsorption energy about −38 kcal/mol at B3LYP/6‐311G(d,p) level of theory. When the CH 4 and CO 2 gases are adsorbed on the ZnO NCs, their electrical conductivities are decreased, and thus the studied ZnO NCs do not generate an electrical signal in the presence of CH 4 and CO 2 gases. Interestingly, both pure and gas adsorbed Zn 22 O 22 NC exhibited more favorable electronic and reactive properties than other NCs. Comparison of the structural, electronic, and optical data predicted by DFT/B3LYP and TD‐DFT/CAM‐B3LYP calculations with those experimentally obtained show good agreement.