Cu²⁺-Doped SnO₂ Nanograin/Polypyrrole Nanospheres with Synergic Enhanced Properties for Ultrasensitive Room-Temperature H₂S Gas Sensing

Abstract

The organic-inorganic nanohybrids are emerging as one of the most attractive sensing materials in the area of gas sensors and usually exhibit some advanced properties because of synergetic/complementary effects between organic molecules and inorganic components. This work demonstrates a novel class of organic-inorganic nanohybrids, Cu²⁺-doped SnO₂ nanograin/poly pyrrole nanospheres, for the sensitive room-temperature H₂S gas sensing. Doping Cu²⁺ in SnO₂ nanograins remarkably enhances the surface potential barrier by tailoring surface defects. After polymerizing pyrrole surrounded nanograins in aqueous media to form the organic-inorganic nanohybrids, the resulting nanoheterojunctions further improve the sensitivity. Additionally, the nanohybrids-based sensor provides high surface area and abounding reaction sites to accelerate gas diffusion and adsorption as well as the electron transfer. Compare with pristine SnO₂ nanograins alone, the sensitivity of using the nanohybrids increases 7 times for the detection of 50-ppm of H₂S. The response and recovery rate can increase 27 and 22 times at room temperature, respectively. Significantly, this work provides an attractive material for the real-time monitoring of H₂S, whereas the insights into organic-inorganic composite interactions within the sensing mechanism may pave the way for designing functional materials with tailored properties.