Screening promising TM-doped CeO_(2) monolayer for formaldehyde sensor with high sensitivity and selectivity

摘要

Developing convenient,fast-response and high-performance formaldehyde detection sensor is significant but challenging.Herein,two CeO_(2) phases(Fm■m and P4_(2)/mnm),three facets(CeO_(2)(100),CeO_(2)(110)and CeO_(2)(111))and three adsorption sites(top,bridge and hollow)are selected as substrate to interact with formaldehyde.Twenty-eight candidated transition metals(TM)are doped on CeO_(2) surfaces to investigate the performance of detecting formaldehyde by density functional theory.It shows that(i)CeO_(2) in a cubic fluorite structure with the space group Fm■m is suitable for formaldehyde adsorption compared with P4_(2)/mnm;(ii)TM-CeO_(2)(100)(TM=Au,Hf,Nb,Ta,Zr)are considered as candidated materials to absorb formaldehyde ascribed to lower adsorption energies.The d-band center,partial density of states,charge density difference and electron localization function are employed to clarify the mechanism of TM-doped CeO_(2) improving the performance of formaldehyde adsorption.It obviously displays that TM doped CeO_(2)(100)changes the d orbit and rearranges electrons resulting in the superior ability to the adsorbed formaldehyde.This work provides theoretical guidance and experimental motivation for the development of novel formaldehyde sensor based on metal oxide semiconductor materials.