Micropored Sn-SnO2/carbon heterostructure nanofibers and their highly sensitive and selective C2H5OH gas sensing performance

Sn-SnO2/carbon heterostructure nanofibers were synthesized by electrospinning and following heat treatment, and their C2H5OH sensing properties were studied. The hetero-nanofibers composed of amorphous carbon and homogeneously distributed Sn-SnO2 particles were characterized by SEM, TEM, EDS, XRD, XPS, FT-IR, Raman and nitrogen adsorption–desorption experiment. A gas sensor was fabricated from the as-synthesized heterostructures of Sn-SnO2/carbon nanofibers and used to test the sensing performance to C2H5OH. The Sn-SnO2/carbon nanofibers showed improved sensing properties compared to pure SnO2 nanofibers. It exhibits a 2-time enhancement in ethanol response compared to the SnO2 nanofibers counterparts at its optimum operating temperature, good linear dependence of response on C2H5OH concentration in the range of 10–100 ppm, excellent recovery property and selectivity to C2H5OH. The excellent performance in C2H5OH sensing of Sn-SnO2/carbon nanofibers arises from (i) high specific surface and pore structure provided by one-dimensional carbon nanofibers, (ii) the unique sensing mechanism based on the hybrid Sn-SnO2/carbon nanostructures.