Engineering of CeO2/CeO2−δ core-shell structures with rich oxygen vacancy for gas sensitive detector

Abstract

The CeO2/CeO2−δ core–shell architectures activated by surface oxygen vacancy (OV) was successfully fabricated by vacuum high-temperature heat treatment process. The key factor will improve performance of this structure is the high concentration of oxygen vacancies in the surface layer, which provides more active sites for the adsorption and chemical reaction of gas molecules. Through more and faster adsorption–desorption and surface chemical reactions, the speed of carrier concentration adjustment is improved, thereby significantly improving the gas-sensing activity of CeO2/CeO2−δ core–shell architectures. The OV-activated cerium dioxide sensor has a good gas-sensing response to acetone, showing a detection limit of 233 ppb trace level. The concept and strategy of activating cerium dioxide with oxygen vacancies can be transplanted to improve the performance of many semiconductor oxide nanomaterials for gas-sensing detection.