Preparation and gas-sensing performance of SnO2/NiO composite oxide synthesized by microwave-assisted liquid phase deposition--颗粒学报PARTICUOLOGY

He, J., Jiao, W., Zhang, L., & Feng, R. (2018). Preparation and gas-sensing performance of SnO2/NiO composite oxide synthesized by microwave-assisted liquid phase deposition. Particuology, 41, 118-125. https://doi.org/10.1016/j.partic.2018.03.003

Preparation and gas-sensing performance of SnO2/NiO composite oxide synthesized by microwave-assisted liquid phase deposition

Jing He, Wanli Jiao ^*, Lei Zhang, Rui Feng

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

10.1016/j.partic.2018.03.003

Volume 41, December 2018, Pages 118-125

Received 17 October 2017, Revised 8 March 2018, Accepted 19 March 2018, Available online 28 June 2018, Version of Record 1 November 2018.

E-mail: jiaowanli1977@163.com

Highlights

• SnO₂/NiO composite oxides were synthesized by microwave-assisted liquid phase deposition (MLPD).

• MLPD shortened the deposition time and improved the specific surface area of SnO₂/NiO powders.

• When the molar ratio of Ni²⁺ to Sn⁴⁺ was 0.1, the gas response to 1000 ppm ethanol reached 85.

• Improved gas sensing may be attributed to the strengthening of P–N heterojunction.

Abstract

We synthesized SnO₂/NiO composite oxides by microwave-assisted liquid phase deposition to improve their surface physico-chemical properties and gas-sensing selectivity, and we investigated how the molar ratio of Ni²⁺ to Sn⁴⁺ and the microwave power affected their gas-sensing performance. The microstructure, surface physico-chemical states, and morphology of the samples were characterized by X-ray diffraction, X-ray photoelectron spectroscopy, and scanning electron microscopy, respectively. Nitrogen adsorption–desorption isotherms were used to characterize the specific surface areas of the samples. Our results showed that microwave-assisted liquid phase deposition increased the surface-adsorbed oxygen content and the specific surface area of the SnO₂/NiO composite oxide from about 22 to 120 m²/g. When the molar ratio of Ni²⁺ to Sn⁴⁺ was 0.1, the gas response to 1000 ppm ethanol gas reached 84.7 at a lower working voltage of 3.5 V. However, the optimum working voltages for methanol and acetone gas were 4.5 and 4.0 V, respectively. Thus, a new method was found to improve the selectivity of the gas sensor. Moreover, at a working voltage of 4.0 V, the gas response of a SnO₂/NiO gas sensor synthesized by microwave-assisted liquid phase deposition with the optimum radiation power of 450 W to 1000 ppm acetone gas was 49.7, twice that of a sensor synthesized by traditional liquid phase deposition.

Graphical abstract

Keywords

SnO₂/NiO composite powders; Microwave; Liquid phase deposition; Gas-sensing performance

文章导读