Influence Of Calcination Temperature On The Gas-Sensing Performance Of 3d Porous Sno2 To Formaldehyde

Porous SnO2 has received widespread attention because of its special structure. We successfully prepared 3 D porous SnO2 using carbon spheres as a template. Scanning electron microscopy (SEM) morphology characterization results show that with the increase of the calcination temperature (400 degrees C, 450 degrees C, 500 degrees C, 550 degrees C, 600 degrees C), the morphology of the 3 D porous SnO2 surface has changed. And when the calcination temperature is 500 degrees C, the pore distribution on the sample surface is more uniform. The results of nitrogen adsorption showed that the sample obtained when the calcination temperature was 500 degrees C had the largest specific surface area (62.02 m(2)/g). Different samples were tested for gas sensitivity, and we found that as the calcination temperature increased, the sensitivity of the samples to formaldehyde first increased and then decreased. The sensitivity of 3 D porous SnO2 calcined at 500 degrees C to 50 ppm formaldehyde is up to 27. The minimum concentration of formaldehyde is 0.5 ppm (sensitivity value is 2). Moreover, 3 D porous SnO2 calcined at 500 degrees C has a fast response time (2 s), low working temperature (230 degrees C), good selectivity (the selection coefficient for formaldehyde is 6.74) and linearity. These excellent performances are mainly due to the uniform 3 D porous structure, large specific surface area and more oxygen vacancies on the surface, which make it a promising formaldehyde sensor material.