Biomorphic synthesis and gas response of In2O3 microtubules using cotton fibers as templates

Biomorphic In2O3 microtubules were prepared using cotton as biotemplates. The structural and microscopy characterization has been carried out with X-ray diffraction and scanning electron microscopy. XRD patterns confirm the formation of In2O3 with cubic phase. The results of scanning electron microscopy revealed that the obtained In2O3 microtubules are in the range of 30–60 μm in length, 8–10 μm in width, and about 300 nm in thickness. The In2O3 microtubules were composed of numerous spherical In2O3 nanocrystals with the nearly uniform size about 30 nm. The gas sensing performance of as-prepared In2O3 nanocrystals was investigated. It is found that In2O3 microtubules calcined at 500 °C exhibit good selectivity for formaldehyde with rapid response and high sensitivity at 260 °C.