Yin Y H, Cheng Y J, Li Y C,et al.One-step hydrothermal synthesis of SnO₂/carbon dots nanocomposites for acetone gas sensing[J].Journal of Henan Polytechnic University(Natural Science) ,2026,45(6):200-208.

doi:10.16186/j.cnki.1673-9787.2024040001

Received:2024/04/01

Revised:2024/06/22

Published:2026/10/09

One-step hydrothermal synthesis of SnO₂/carbon dots nanocomposites for acetone gas sensing

Yin Yuehong1, Cheng Yujie2, Li Yongchao2, Liu Yukun2, Niu Yifan2, Cao Guohua1, Zhang Baoqing2

1.School of Physics and Electronic Information Engineering， Henan Polytechnic University， Jiaozuo  454003， Henan， China；2.School of Materials Science and Engineering， Henan Polytechnic University， Jiaozuo  454003， Henan， China

Abstract: Objectives To address the problems of low sensitivity and high detection limit of existing SnO₂-based acetone gas sensors， SnO₂/carbon dots （CDs） nanocomposites were synthesized in situ by a one-step hydrothermal method， and the effect of CDs introduction on the gas sensing performance of SnO₂ was systematically investigated. Methods SnO₂/carbon dots （CDs） nanocomposites were synthesized using a one-step hydrothermal method， in which CDs containing abundant functional groups were introduced into SnO2 in situ. X-ray diffraction， transmission electron microscopy， and X-ray photoelectron spectroscopy were employed to characterize the structure， morphology， and composition of the materials. The acetone gas sensing performance of SnO2 and SnO2/CDs composites was systematically investigated. Results The results show that both SnO2 and SnO2/CDs composites exhibit a tetragonal rutile phase structure. The hollow spheres with a size of approximately 100~200 nm are formed by the aggregation of particles with a size of approximately 5 nm. The hollow spheres of SnO₂/CDs composites exhibit obvious protrusions at one end. Due to the introduction of CDs， the hollow spheres contain more abundant surface functional groups and more oxygen vacancies. Both SnO2 and SnO2/CDs sensors exhibit pronounced gas selectivity and cycling stability toward acetone. At the optimal operating temperature of 350 ℃， the sensitivity of the SnO₂/CDs composite sensor to acetone gas with a volume fraction of 1.0×10⁻⁴ reaches 45.4， which is approximately 1.8 times that of the pure SnO₂ sensor. The detection limit of the SnO₂/CDs composite sensor is as low as 1.1×10⁻⁷.  Conclusions The significant improvement in the acetone sensing performance of SnO2/CDs nanocomposites is mainly attributed to their larger specific surface area and the formation of heterojunction structures between SnO₂ and CDs， which increase the number of active sites and promote gas adsorption and reaction.

Key words: gas sensor; tin oxide; carbon dot; nanocomposite; one-step hydrothermal method; acetone