Ultrahigh sensitivity and selectivity chlorine gas sensing of In2O3hollow microtubules by bio-template method with degreasing cotton

作者：Ma Jiangwei; Fan Huiqing^*; Tian Hailin; Ren Xiaohu; Wang Chao; Gao Shang; Wang Weijia

来源：Sensors and Actuators, B: Chemical , 2018, 262: 17.

DOI：10.1016/j.snb.2018.01.226

• Gas sensing
• High specific surface area
• Immersion calcination method
• In2O3
• Microtubules
• Morphological features
• Template methods
• Ultra-high-sensitivity

A simple two-stage procedure of immersion-calcination method has been developed for preparing In2O3hollow microtubules by using degreasing cotton as soft bio-templates. The morphological feature was characterized as hollow microtubules with the range of 50–70 μm in length, 5–6 μm in width, and about 1 μm in thickness. The Cl2sensing properties were remarkably enhanced in sensitivity and selectivity for In2O3hollow microtubules. The gas response (Rgas/Rair) of the In2O3hollow microtubules sensor was 1051 to 10 ppm Cl2at 200 °C, which was 25 times higher than In2O3particles. Such outstanding gas sensing performance was ascribed to the hollow morphology, which revealed high specific surface area, abundant oxygen vacancies and low band gap. The gas sensing mechanism was deduced that Cl2molecules are directly adsorbed on the metal oxide surface and oxygen vacancies.