Ultrahigh sensitivity and selectivity chlorine gas sensing of In2O3 hollow microtubules by bio-template method with degreasing cotton

A simple two-stage procedure of immersion-calcination method has been developed for preparing In2O3 hollow microtubules by using degreasing cotton as soft bio-templates. The morphological feature was characterized as hollow microtubules with the range of 50-70 pim in length, 5-6 pim in width, and about 1 pim in thickness. The Cl-2 sensing properties were remarkably enhanced in sensitivity and selectivity for In2O3 hollow microtubules. The gas response (R-gas/R-air) of the In2O3 hollow microtubules sensor was 1051 to 10 ppm Cl-2 at 200 degrees C, which was 25 times higher than In2O3 particles. 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 Cl-2 molecules are directly adsorbed on the metal oxide surface and oxygen vacancies. (C) 2018 Elsevier B.V. All rights reserved.