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

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, Cu 2+ -doped SnO 2 nanograin/poly pyrrole nanospheres, for the sensitive room-temperature H 2 S gas sensing. Doping Cu 2+ in SnO 2 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 SnO 2 nanograins alone, the sensitivity of using the nanohybrids increases 7 times for the detection of 50-ppm of H 2 S. 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 H 2 S, whereas the insights into organic–inorganic composite interactions within the sensing mechanism may pave the way for designing functional materials with tailored properties.