Regular Article

High selectivity of a CuO modified hollow SnO₂ nanofiber gas sensor to H₂S at low temperature

School of Physical Engineering, Zhengzhou University, Zhengzhou 450001, P.R. China

^a e-mail: Jiajf@zzu.edu.cn

Received: 17 February 2017
Revised: 11 May 2017
Accepted: 15 June 2017
Published online: 2 August 2017

Abstract

CuO modified hollow SnO₂ nanofibers with large specific surface area were successfully synthesized via a simple two-step process, using the electrospinning method and hydrothermal technique. Gas-sensing experiments on hierarchically CuO modified SnO₂ hollow nanofibers displayed higher sensitivity and selectivity to H₂S gas at lower operating temperatures compared with unmodified hollow SnO₂ nanofibers. At the optimal operating temperature of 125 °C, the highest response value to 10 ppm H₂S gas reached 410. Response time decreased when the concentration of H₂S increased. It is almost no response to other gases when the operating temperature falls below 200 °C. The specific interaction between H₂S gas and the CuO nanoparticles, as well as the amplifier effect on the gas response by the p–n junctions, strongly enhances the selectivity to H₂S gas at a lower operating temperature.