Template synthesis, organic gas-sensing and optical properties of hollow and porous In2O3 nanospheres

Hollow and porous In2O3 nanospheres have been prepared by the hydrolysis of InCl3 using carbonaceous spheres as templates in combination with calcination. Based on the observation of scanning electronic microscopy (SEM) and transmission electron microscopy (TEM), it has been revealed that the as-prepared In2O3 nanospheres have a uniform diameter of around 200 nm and hollow structures with thin shells of about 30 nm consisting of numerous nanocrystals and nanopores. Owing to the hollow and porous structures, In2O3 nanospheres possessing more active surface area exhibit a good response and reversibility to some organic gases such as methanol, alcohol, acetone and ethyl ether. In addition, the response mechanism of hollow and porous In2O3 nanospheres to organic gases has been proposed. Furthermore, these prepared In2O3 spheres showed a UV- visible absorption peak centered at around 309 nm, and their photoluminescence spectra have also been investigated.