Preparation and gas sensing performances of palladium surface-modified flower-like SnO2 nanopowders--颗粒学报PARTICUOLOGY

Jiao, W., & Zhang, L. (2013). Preparation and gas sensing performances of palladium surface-modified flower-like SnO2 nanopowders. Particuology, 11(6), 743-747. https://doi.org/10.1016/j.partic.2013.01.003

Preparation and gas sensing performances of palladium surface-modified flower-like SnO₂ nanopowders

Wanli Jiao^*, Lei Zhang

School of Material Science and Engineering, Shandong University of Technology, Zibo 255049, China

10.1016/j.partic.2013.01.003

Volume 11, Issue 6, December 2013, Pages 743-747

Received 19 October 2012, Revised 20 December 2012, Accepted 7 January 2013, Available online 5 March 2013.

E-mail: jiaowanli1977@163.com

Highlights

► Flower-like SnO₂ nanoparticles consisted of nanorods of 40 nm in diameter and 100 nm in length.

► SnO₂ nanopowders were surface modified with palladium via dipping.

► The sensitivity of 0.3 wt% Pd modified SnO₂sensor was 21 for 70 μL/L ethanol gas at 250 °C.

► Response and recovery times of 0.3 wt% Pd modified SnO₂ sensor were 3 and 20 s, respectively.

Abstract

Flower-like SnO₂ nanopowders prepared by a hydrothermal method were surface modified with palladium via impregnation. The crystal structure, morphology, and surface chemistry states of the samples were characterized by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS), respectively. The gas sensing performances were also investigated. For a hydrothermal temperature of 220 °C, flower-like SnO₂ nanoparticles consist of nanorods with diameters of 40 nm and lengths of 100 nm. The XPS and XRD results reveal that palladium exists in the Pd⁰ chemical state but the crystal is too small to be detected. The 0.3 wt% Pd modified SnO₂ sensor shows better sensitivity, up to 21, for 70 μL/L ethanol gas at an optimal working temperature of 250 °C. The quick response time (3 s) and fast recovery time (∼20 s) are the main characteristics of this sensor.

Graphical abstract

Keywords

SnO₂ nanopowders; Flower-like structure; Hydrothermal method; Impregnation; Palladium; Gas sensing

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