A theoretical study on sensing properties of in-doped ZnO nanosheet toward acetylene

Following an experimental work, we employed density functionals B3LYP, BHANDH, HSE06, PBEPBE, and M06 to inspect the impact of In-doping on a ZnO nanosheet sensitivity to the acetylene gas. The interaction of the pristine ZnO sheet with the acetylene was found to be weak, and the sensing response is 1.7 based on the B3LYP results. Doping an In atom into the ZnO sheet increases the adsorption energy of acetylene from -3.6 to -20.4 kcal/mol. Energy decomposing analysis suggests that the nature of interaction is mainly electrostatic, indicating a pi-cation interaction. The sensing response significantly rises to 38 by In-doping (experimental value similar to 49). We showed that the In-doped ZnO sheet can selectively detect acetylene gas in the presence of O-2, H2O, N-2 and CO2. A short recovery time of 0.7 s is found, being comparable with experimental value of 58.4 s. Both theory and experiment suggest that In-doped ZnO nanosheet may be highly sensitive and selective acetylene sensor with a short recovery time.

Automated summary

The study demonstrates that indium doping can significantly enhance the sensitivity and selectivity of ZnO nanosheets to acetylene gas. The adsorption energy of acetylene increases significantly after indium doping, with the interaction mainly attributed to electrostatic forces. The indium-doped ZnO nanosheets can selectively detect acetylene in the presence of other gases and exhibit a short recovery time.