Highly Sensitive and Selective Room-Temperature H₂S Detection Using N-Doped Carbon Nanofiber/Ni-ZnO Composites

Nitrogen-doped carbon nanofibers (NCNF) possess nanostructures with high surface area and porosity, showing excellent sensing capabilities when additionally doped with semiconducting metal oxides. However, issues related to the processability of NCNF remain a challenge in developing gas-sensing electronics. Herein, we report the use of electrospinning of polymer precursors to fabricate NCNF impregnated with uniformly distributed Ni-ZnO nanoparticles. Structural and crystallographic analyses reveal synergistic effects of NCNF with Ni-ZnO, generating multiple active sites with enhanced gas absorptivity and catalytic activity. NCNF/Ni-ZnO nanocomposites detect various gases, showing high selectivity toward H₂S at room temperature. NCNF with 15% Ni-ZnO doping show a rapid sensor response of 65.6% at 200 ppm with a response time of 9.2 s and a recovery time of 52.3 s. The sensor maintained stability, repeatability, and reduced humidity interference through a polynomial compensation strategy, achieving a deviation below 7%. These results highlight NCNF/Ni-ZnO hybrids as highly sensitive, selective, and stable nanomaterials for real-time H₂S monitoring.