Quantum mechanics

Engineering

Field emission microscopy

Transmission electron microscopy

Field electron emission

Materials science

Chemical engineering

Acetone

Rutile

Physics

Nanotechnology

Organic chemistry

Microsphere

Optics

Hydrothermal circulation

Composite material

Chemistry

Scanning electron microscope

Electron

Diffraction

Nanorod

Journal of Alloys and Compounds

A controlled synthesis of three-dimensional Au-sensitized SnO2 hollow microspheres that composed of numerous nanorod subunits has been realized via a facile one-pot hydrothermal method without employing any templates or capping agents. The structural and morphological characteristics of the pure and Au-loaded SnO2 microspheres are revealed by X-ray diffraction, field-emission scanning electron microscope, and high resolution transmission electron microscope, respectively. The characterized results reveal that SnO2 hollow microspheres have the diameter of 600–900 nm with a rutile structure, which are composed of high densities of secondary SnO2 nanorods with the size of 20–50 nm. Furthermore, the gas sensors based on the pure and Au-loaded SnO2 have been fabricated, and the Au-loaded hierarchical SnO2 hollow microspheres exhibit more excellent sensing performances than that of pure SnO2 to acetone. The response and recovery times of the Au-loaded SnO2 microspheres are 0.9 s and 21 s when the sensor is exposed to 5 ppm acetone at the optimal operating temperature of 220 °C. These improved acetone-sensing performances are attributed to the catalytic effect of Au and the enhanced electron depletion at the surface of SnO2 hollow microspheres.

Preparation of Au-sensitized 3D hollow SnO2 microspheres with an enhanced sensing performance