Bimetallic MOFs-Derived Metal Oxides Co3O4/SnO2 Microspheres for Ultrahigh Response n-Butanol Gas Sensors

Zhenkai Zhang; Qiuying Chen; Yujun Guo; Davoud Dastan; Xiao-Chun Gao; Ying Liu; Xiao-Ming Tan; Feifei Wang; Xi-Tao Yin; Shan Ren; Xiaoguang Ma

doi:10.1021/acs.langmuir.4c02052

Bimetallic MOFs-Derived Metal Oxides Co₃O₄/SnO₂ Microspheres for Ultrahigh Response n-Butanol Gas Sensors

Langmuir. 2024 Oct 1;40(39):20505-20514. doi: 10.1021/acs.langmuir.4c02052. Epub 2024 Sep 22.

Authors

Affiliations

¹ School of Physics and Optoelectronic Engineering, Ludong University, Yantai 264000, China.
² Department of Materials Science and Engineering, Cornell University, Ithaca, New York 14850, United States.
³ State Key Laboratory of Multiphase Flow in Power Engineering, School of Energy and Power Engineering, Xi'an Jiaotong University, Xi'an 710049 Shaanxi, P. R. China.

PMID: 39308081
DOI: 10.1021/acs.langmuir.4c02052

Abstract

The construction of p-n heterojunctions is expected to be one of the effective means to improve gas sensitivity. In this research, p-n heterojunctions are successfully constructed by metal oxides derived from metal-organic frameworks (MOFs). MOFs-derived bimetallic Co₃O₄/SnO₂ microspheres are prepared by precipitation. Gas-sensing performance shows that the Co₃O₄/SnO₂ sensor exhibits an extremely high response (R_a/R_g = 641) to 20 ppm of n-butanol at 200 °C, which is 19 times that of pristine SnO₂. It can detect n-butanol gas at low concentrations, has good selectivity to alcohol gas, and reduces the interference of benzene gas. The improved gas sensitivity can be attributed to the formation of a stable heterojunction between Co₃O₄ and SnO₂, resulting in a greater resistance change of Co₃O₄/SnO₂. Co₃O₄/SnO₂ inherits the characteristic of high specific surface area of MOFs, which provides abundant sites for the reaction of the target gas and oxygen molecules. Finally, the gas-sensing mechanism of the Co₃O₄/SnO₂-based sensor is discussed in detail.