title: Encapsuled nanoreactors (Au@SnO₂): a new sensing material for chemical sensors.
abstract: New Au@SnO2 yolk-shell nanospheres have been successfully synthesized by using Au@SiO2 nanospheres as sacrificial templates. This process is environmentally friendly and is based on hydrothermal shell-by-shell deposition of polycrystalline SnO2 on spheriform Au@SiO2 nanotemplates. Au nanoparticles can be impregnated into the SnO2 nanospheres and the nanospheres show outer diameters of 110 nm and thicknesses of 15 nm. The possible growth model of the nanospheres is proposed. The gas sensing properties of the Au@SnO2 yolk-shell nanospheres were researched and compared with that of the hollow SnO2 nanospheres. The former shows lower operating temperature (210 °C), lower detection limit (5 ppm), faster response (0.3 s) and better selectivity. These improved sensing properties were attributed to the catalytic effect of Au, and enhanced electron depletion at the surface of the Au@SnO2 yolk-shell nanospheres.
authors.affiliation: State Key Laboratory on Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, Changchun, 130012, China.
authors.forename: Lili
authors.initials: L
authors.lastname: Wang
authors.forename: Huimin
authors.initials: H
authors.lastname: Dou
authors.forename: Zheng
authors.initials: Z
authors.lastname: Lou
authors.forename: Tong
authors.initials: T
authors.lastname: Zhang
mesh_terms: D015374:Biosensing Techniques; D005740:Gases / Q000032:analysis; D017612:Gold Compounds / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D008839:Microelectrodes; D054118:Nanospheres / Q000737:chemistry* / Q000648:ultrastructure; D012822:Silicon Dioxide / Q000737:chemistry; D013499:Surface Properties; D013696:Temperature; D017971:Tin Compounds / Q000737:chemistry*; D014961:X-Ray Diffraction
chemical_list: D005740:Gases; D017612:Gold Compounds; D017971:Tin Compounds; D012822:Silicon Dioxide; C045358:stannic oxide