Rapid and accurate detection of highly toxic NO2 gas based on catkins biomass-derived porous In2O3 microtubes at low temperature

• Published in: Sensors and actuators. B, Chemical Chemical, 2022-06, Vol.361, p.131692, Article 131692
• Main Authors: Wang, Ning, Ye, Jin-Xin, Sun, Jia-Bin, Zhang, Xian-Fa, Deng, Zhao-Peng, Xu, Ying-Ming, Huo, Li-Hua, Gao, Shan
• Format: Article
• Language: English
• Subjects: Bio-template; Crystal defects; Energy consumption; Gas sensor; Gas sensors; In2O3; Indium oxides; Low temperature; Moisture effects; Moisture resistance; Nanoparticles; Nitrogen dioxide; NO2; Oxygen; Porous microtube; Recovery time; Selectivity; Sensors; Structural hierarchy
• ISSN: 0925-4005; 1873-3077
• DOI: 10.1016/j.snb.2022.131692

Development of In2O3-based gas sensors has recently attracted widespread attention, however, how to shorten the response and recovery time for sub-ppm level NO2 detection remains challenging. In this work, biomorphic In2O3 sensing material (In2O3-600) was successfully prepared through simple indium chloride solution immersion and air calcination at 600 ℃ with waste catkins template. This hierarchical structure is cross-linked by uniform spherical nanoparticles with good crystallinity. Its multi-stage pores and 1-D microtube structure are conducive to promoting the rapid diffusion and desorption of target gas, and the existence of oxygen vacancy defects can also effectively increase the conductivity, active sites and the content of surface adsorbed oxygen species. Their synergism significantly improves the rapid response and recovery speed of sensor to trace NO2 under low energy consumption. At 92 ℃, the response value of In2O3-600 sensor towards 10 ppm NO2 is up to 193 with rapid response and recovery times (56 and 14 s), even 1 ppm for 64 and 32 s, which is significantly shorter than most reported In2O3-based sensors. In addition, the sensor also has a wide linear detection range, low detection limit, good selectivity, and satisfactory reproducibility, moisture resistance and long-term stability. Therefore, the biomorphic porous In2O3-600 microtubes are available as candidate for detecting sub-ppm level NO2 gas at low temperature. •Porous In2O3 microtubes were simply and controllably synthesized using waste catkin as bio-template.•In2O3-600 sensor exhibits rapid response and recovery times (64 s/32 s) to 1 ppm NO2 at 92 ℃.•The synergism of unique microtube and oxygen vacancies is highly responsible for excellent sensing performance.•The simple catkin-template method provides useful reference for synthesizing other advanced metal oxide nanomaterials.