Formaldehyde Gas Sensor Based on Melamine Foam and Tin Dioxide Composites

摘要

Formaldehyde (HCHO) is a volatile organic compound (VOC). It can caused great harm to human and environment. Since the increasing concerns of this problem, to develop effective methods to detect this toxic and hazardous gas has become more and more important, which play an important role in personal safety and environment protection. In this study, melamine foam and tin oxide composites were prepared by in-situ growth and subsequent treatment by using a simple hydrothermal reaction. The morphology, structure and sensing properties of the composites were systematically studied. The results show that tin oxide nanoparticles can grow well on the melamine foam skeleton through a simple hydrothermal reaction and has a good stable morphology. It is found that the three-dimensional spherical/skeletal composite material has better gas sensitivity and selectivity to formaldehyde gas than the pristine tin dioxide under a suitable concentration. The response of the composite to 5 ppm formaldehyde gas can reach 30.0 at 120°C. The reactant of formaldehyde on the surface of the material was studied by in situ IR. At the same time, melamine foam has a certain flexibility, which will have a good development for flexible, miniaturized and wearable formaldehyde sensor.