Synthesis of Pd-loaded mesoporous SnO2 hollow spheres for highly sensitive and stable methane gas sensors

Liping Yang; Zhou Wang; Xinyuan Zhou; Xiaofeng Wu; Ning Han; Yunfa Chen

doi:10.1039/c8ra03242d

Synthesis of Pd-loaded mesoporous SnO₂ hollow spheres for highly sensitive and stable methane gas sensors

RSC Adv. 2018 Jul 3;8(43):24268-24275. doi: 10.1039/c8ra03242d. eCollection 2018 Jul 2.

Authors

Liping Yang¹, Zhou Wang¹, Xinyuan Zhou^{1

2}, Xiaofeng Wu¹, Ning Han^{1

3}, Yunfa Chen^{1

3}

Affiliations

¹ State Key Laboratory of Multiphase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences North Second Street 1 100190 Beijing P. R. China nhan@ipe.ac.cn.
² University of Chinese Academy of Sciences No. 19A Yuquan Road Beijing 100049 PR China.
³ Center for Excellence in Regional Atmospheric Environment, Institute of Urban Environment, Chinese Academy of Sciences Jimei Avenue 1799 361021 Xiamen P. R. China.

Abstract

High performance methane gas sensors have become more and more essential in different fields such as coal mining, kitchens and industrial production, which necessitates the design and synthesis of highly sensitive materials. Herein, mesoporous SnO₂ hollow spheres with high surface area (>90 m² g^-1) are prepared by a progressive inward crystallization routine, showing a high response of 1.31 to 250 ppm CH₄ at a working temperature of 400 °C. Furthermore, loading noble metal Pd onto the surface of SnO₂ hollow spheres by an adsorption-calcination process improves the response to 4.88 (250 ppm CH₄) at the optimal dosage of 1 wt% Pd. Meanwhile, the working temperature decreases to 300 °C, showing the prominent spillover effect of catalytic Pd and PdO-SnO₂ heterostructure sensitization as evidenced by the binding energy shift in the X-ray photoelectron spectroscopy (XPS) analysis. The response/recovery time is as short as 3/7 s and the sensitivity is stable for a test period as long as 15 weeks. All these performances show the promise of the highly porous Pd-loaded SnO₂ hollow spheres for high performance methane sensors.