YIN Y H, CHENG Y J, LI Y C, et al． SnO₂/carbon dots nanocomposite synthesized by one-step hydrothermal technique for acetone gas sensor［J］. Journal of Henan Polytechnic University( Natural Science)， doi: 10.16186/j.cnki.1673-9787. （ 2024040001）..

doi: 10.16186/j.cnki.1673-9787. （ 2024040001）..

Received： 2024-04-01

Revised： 2024-06-22

Online： 2026-06-04

SnO₂/carbon dots nanocomposite synthesized by one-step hydrothermal technique for acetone gas sensor (Online)

YIN Yuehong 1, CHENG Yujie 2, LI Yongchao 1, LIU Yukun 2, NIU Yifan 2, CAO Guohua 1, ZHANG Baoqing 2

1.School of Physics and Electronic Information Engineering,Henan Polytechnic University,Jiaozuo 454000,Henan,China；2. School of Materials Science and Engineering,Henan Polytechnic University,Jiaozuo 454000,Henan,China

Abstract: Objectives Acetone is volatile, flammable and explosive, and its large amount of volatilization would bring problems such as environmental pollution and safety hazards, as well as damage to human health. The development of acetone sensors with low cost, high response and low detection limit is of great significance to environmental protection and human health, which is a research hotspot in the field of gas detection. Methods Tin oxide (SnO₂)/carbon dots (CDs) nanocomposites were synthesized using a green and simple one-step hydrothermal method, in which CDs containing abundant functional groups were introduced in situ into SnO₂. Properties such as structure, morphology and composition of the materials were characterized using X-ray diffraction, transmission electron microscopy and X-ray photo-electron spectroscopy and so on. The detection performance of pure SnO₂ and SnO₂/CDs composites towards acetone was systematically investigated. Results Both SnO₂ and SnO₂/CDs composites exhibit a tetragonal rutile phase structure, which consists of particles with a size of about 5 nm aggregated into hollow spheres with a size of about 100~200 nm. The SnO₂/CDs composites present hollow spheres with pronounced projections on the end and contain richer surface groups and more oxygen defects due to the introduction of CDs. The SnO₂ and SnO₂/CDs sensors exhibit significant gas selectivity and cycling stability for acetone. The sensitivity of the composite sensor for 100 ppm gas at the optimal operating temperature of 350 ℃ is 45.4, which is 1.8 times higher than that of pure SnO₂. The SnO₂/CDs composite sensor demonstrates a lower detection limit of 0.11 ppm. Conclusions The main reason for the significant improvement in the detection performance of SnO₂/CDs composites is that the composites possess a larger specific surface area, and the heterojunction structure is formed between SnO₂ and CDs, which in turn increases the active sites and promotes the adsorption and reaction of gases.

Key words: gas sensor; tin oxide; carbon dots; nanocomposite; one-step hydrothermal technique; acetone