Synthesis and inuestigation on formabdehyde sensing of properties In 2 O 3 /SnO 2 -coaxial-electrospinning fiber

Homo heterojunction or hetero heterojunction will form at the surface of two kinds of different semiconductor due to the difference of electronic affinity and band gap width. The interface carrier mobility can be improved by means of Fermi level effect at interface of heterojunction, which improves the gas sensitivity performance of gas sensor. The coaxial heterocomposite In2O3/SnO2 nanofibers were fabricated by a self-designed multilayer coaxial electrospinning device. The bigger In2O3 nanoparticles on the outer layer of In2O3/SnO2 fibers grow on the surface of the SnO2 nanoparticles on the inner layer of In2O3/SnO2 fiber, which forms the hollow hierarchical fiber structure. N-N homo-heterojunctions interface between of In2O3 and SnO2 nanoparticles will enhance electron mobility, surface activity and the content of adsorption oxygen, which will improve the adsorption capacity of In2O3/SnO2 sensor to formaldehyde. The response of coaxial hetero-nanofiber In2O3/SnO2 sensor is 14.12 to 50 ppm formaldehyde, are 3.22 times, 3.84 times and 1.51 times of that of SnO2, In2O3 and mixed hetero-nanofiber In2O3/SnO2 sensor at 250℃. The coaxial hetero-nanofiber In2O3/SnO2 sensor also shows excellent cross-selectivity to formaldehyde, ethanol, acetone, ammonia, toluene and methanol. The coaxial hetero composite synthesized by coaxial electrospinning has application potential and development prospect to improve semiconductor function device.