SnO2/SnS2 nanotubes for flexible room-temperature NH3 gas sensors

Abstract

Complex composites have attracted tremendous attention due to their superior physic–chemical properties. In this work, using electrospun-synthesized SnO₂ nanotubes as backbones, tubular SnO₂/SnS₂ composites were successfully prepared from an in situ hydrothermal sulfuration process. As-synthesized composite SnO₂/SnS₂ nanotubes have an average diameter of about 300 nm and are aggregated into numerous small nanoparticles. Flexible gas sensors were fabricated with the composite SnO₂/SnS₂ nanotubes on a polyethylene terephthalate (PET) substrate. When exposed to ammonia (NH₃) gas at room temperature, the flexible SnO₂/SnS₂ nanotube sensors exhibited excellent sensitivity as high as 2.48 (100 ppm NH₃), almost twice as high as pure SnO₂ nanotubes. In addition, the sensors also showed a fast response time, excellent repeatability, stability and outstanding selectivity. Studies found that the hollow structures and the synergistic effect of both SnO₂ and SnS₂ played important roles in enhanced the sensing performance.