The effect of simultaneous Al-doping and Pt-decoration on the sensitivity of a ZnO nanocluster toward acetone

Abstract

In 2019, Koo et al. have experimentally shown that the sensitivity of ZnO nanostructures is increased toward acetone gas by simultaneous Al-doping and Pt-decoration. Here, we performed a density functional theory study to explore the origin of the experimental observations on the molecular level in terms of orbital, density of states, electronic, energetic, and charge transfers. We defined a relationship between the sensor response (R) and its HOMO-LUMO energy gap, which indicates a good agreement with the experimental results. The acetone interacts weakly with the pristine ZnO with the adsorption energy (Ead) of -15.6 kcal/mol. By Al-doping, the Ead increases to -38.4 kcal/mol and the R value is predicted to be 246. By Pt-decoration, the number of adsorbed acetone and charge transfer are increased, increasing the R value to 447, which is close to the experimental value of 421. The sensor recovery time is predicted to be 383 s, being close to the experimental value of 440 s.