The adsorption of NO onto an Al-doped ZnO monolayer and the effects of applied electric fields: A DFT study

The adsorption of the NO molecule onto a perfect graphene-like ZnO monolayer (P-ZnO) or Al-doped monolayer (Al-ZnO) was studied through the first-principles DFT. The NO molecule was only adsorbed onto the P-ZnO through a weak physical interaction. However, the NO was strongly chemisorbed onto the Al-ZnO with a high adsorption energy of −1.231 eV and transferred 0.58 electrons. The electrons transferred from the Al-ZnO to the NO were further improved to 0.95 e under an external electric field of 0.6 V/Å. Therefore, the Al-doped ZnO monolayer shows outstanding NO-sensing performance, and external electric fields could also be used to further improve the gas sensing properties of the metal oxides.