Preparation of Cd-loaded In2O3 hollow nanofibers by electrospinning and improvement of formaldehyde sensing performance

Abstract

Pure In2O3 and Cd-loaded In2O3 hollow and porous nanofibers with different Cd/In molar ratios (1/20, 1/10, 1/1) were synthesized by electrospinning method. X-ray diffraction (XRD), field emission scanning electron microscope (FE-SEM), and transmission electron microscopy (TEM) were used to characterize the nanofibers. The porous nanofibers were composed of small grains. The average grain sizes and the diameters of Cd-loaded In2O3 nanofibers increased with the increasing of Cd/In molar ratios. The formaldehyde sensing properties of the sensors based on pure In2O3 and Cd-loaded In2O3 nanofibers were investigated in formaldehyde concentration range of 0.5∼100 ppm. Moreover, the selectivity of those sensors was studied by testing responses to methanol, toluene, ethanol, acetone, and ammonia. The result showed that Cd-loaded In2O3 nanofibers with Cd/In molar ratio of 1/10 possessed the highest response value and good selectivity at operating temperature 280°C. In addition, the formaldehyde sensing mechanism of the sensors based on Cd-loaded nanofibers was briefly analyzed. © 2014 Ruijin Hu et al.