Highly Efficient CuO-Anchored SnO2 Nanofiber for Low-Concentration H2S Gas Sensors

Metal oxide-based chemiresistive gas sensors are reliable for detecting low concentrations of hydrogen sulfide (H2S) gas, which pose significant harm to human health. This article highlights the improvement in H2S gas detection by using CuO-decorated SnO2 nanofibers, which are synthesized by combining electrospinning and sputtering. The electrospun PVP/SnO2 fibers are calcinated at 600 °C, reducing the diameter from 498 to 220 nm, which enhances crystallinity, favoring improved H2S sensing. The efficacy of H2S gas detection using CuO-decorated SnO2 nanofibers was explored at a temperature ranging from 50 to 200 °C. CuO sputtered nanoparticles for 30, 60, and 90 s, respectively, on SnO2 nanofibers improve the gas relative response, showing the importance of composite material toward sensing. The catalytic abilities of CuO sputtered nanoparticles for 60 s on SnO2 nanofibers boost the gas relative response to 85.71% for 50 ppm of H2S gas at 200 °C─an improvement of 25% more than the pristine SnO2 nanofibers. CuO-decorated SnO2 nanofibers showed an excellent adsorption/desorption property with response and recovery times of 100 and 109 s for 50 ppm of H2S. First-principles calculations indicate that the O-adsorbed SnO2/CuO system has potential for H2S gas detection due to its high adsorption energy of −2.21 eV, charge transfer of 0.65 e–, and orbital interactions. Our findings conclude the superiority of CuO-decorated SnO2 nanofibers in detecting the H2S gas at low concentrations for industrial applications.