Microporous‐Ceria‐Wrapped Gold Nanoparticles for Conductometric and SERS Dual Monitoring of Hazardous Gases at Room Temperature

Abstract This work proposes a novel and simple synthesis method for microporous‐ceria‐wrapped gold (Au@mp‐CeO 2 ) nanoparticles (NPs) based on linker molecule‐induced stacking of ultrafine CeO 2 particles (or beads) on the surface of pre‐prepared gold NPs. The resulting NPs have a uniform size and microporous CeO 2 shells with a mean thickness of 28 nm and porosity of 42%. The shell is highly tunable from about 4 to 30 nm thick. This method is universal and suitable for other metal@mp‐oxide nanoarchitectures (such as Au@mp‐CuO NPs, Au@mp‐Cr 2 O 3 NPs, Ag@mp‐CeO 2 NPs, and Ag@mp‐CeO 2 nanowires) simply via changing the pre‐prepared metal cores or shell precursors. Most significantly, the as‐prepared Au@mp‐CeO 2 NPs can be used for accurate monitoring of toluene vapor (10 ppm level) at room temperature based on their conductometric and surface‐enhanced Raman spectroscopy (SERS) dual response. Moreover, these NPs can be also used for other hazardous gases, such as chlorobenzene, hydrogen sulfide, and 1‐dodecanethiol. This excellent performance benefits from the micropore‐enhanced interaction between CeO 2 and gas molecules. This work not only provides new and controllable preparation for metal@mp‐oxide nanoarchitectures, but also demonstrates the great potential applications of these materials in real‐time and identifiable monitoring of hazardous gases.