Coaxial spinning synthesis of In2O3@HCNFs for room temperature solid electrolyte gas sensor to enhance the sensing performance of ozone

High-performance gas sensors can be used to detect low-concentration volatile organic compounds (VOCs), toxic and explosive gases in the atmospheric environment, which is of great significance to environmental protection and human health. In this paper, In 2 O 3 @HCNFs gas sensing material with core-shell structure was successfully synthesized by coaxial electrospinning method , and a new room temperature O 3 sensor was developed with potassium ferrite superionic conductor (K 2 Fe 4 O 7 ) as solid electrolyte. The response test shows that the K 2 Fe 4 O 7 -In 2 O 3 @HCNFs sensor has the highest response value and the shortest response/recovery time for 180–420 ppb O 3 . The logarithmic fitting of the response value and the O 3 concentration shows that the sensor has a stronger sensitivity to O 3 . In addition, the K 2 Fe 4 O 7 -In 2 O 3 @HCNFs sensor has good repeatability and stability for O 3 . In the high humidity environment (90 %RH), the sensor still has a certain response value to O 3 , which proves the feasibility of the sensor under high humidity conditions. Additionally, the sensor has good selectivity for O 3 in the presence of other interfering substances. The excellent performance of K 2 Fe 4 O 7 -In 2 O 3 @HCNFs sensor was verified by analyzing the structural composition of gas sensing materials and the detection mechanism of the sensor. Therefore, compared with the traditional uniaxial electrospinning, the In 2 O 3 @HCNFs composite synthesized by coaxial electrospinning has excellent gas sensing properties, and the solid electrolyte gas sensor prepared by it has a good application prospect in the detection of ppb-level O 3 .