Screening promising TM-doped CeO2 monolayer for formaldehyde sensor with high sensitivity and selectivity

Developing convenient, fast-response and high-performance formaldehyde detection sensor is significant but challenging. Herein, two CeO2 phases ( Fm-3 & macr;m and P4(2 )/mnm), three facets (CeO2(100), CeO2(110) and CeO2(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 CeO2 surfaces to investi-gate the performance of detecting formaldehyde by density functional theory. It shows that (i) CeO2 in a cubic fluorite structure with the space group Fm-3 & macr;m is suitable for formaldehyde adsorption compared with P4(2)/mnm; (ii) TM-CeO2(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 CeO2 improving the performance of formaldehyde adsorption. It obviously displays that TM doped CeO2(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. (C) 2022 Published by Elsevier B.V. on behalf of Chinese Chemical Society and Institute of Materia Medica, Chinese Academy of Medical Sciences.

Automated summary

Developing a convenient, fast-response, and high-performance formaldehyde detection sensor is significant but challenging. In this study, various CeO2 phases, facets, and adsorption sites were selected as substrates, and transition metals were doped on CeO2 surfaces. The results showed that the cubic fluorite structure of CeO2 and TM-CeO2(100) (TM = Au, Hf, Nb, Ta, Zr) exhibited superior abilities in adsorbing formaldehyde. The mechanism of TM-doped CeO2 improving the performance of formaldehyde adsorption was clarified using various analysis methods. This work provides theoretical guidance and experimental motivation for the development of novel formaldehyde sensors based on metal oxide semiconductor materials.