Enhanced Hydrogen Detection in ppb-Level by Electrospun SnO₂-Loaded ZnO Nanofibers

High-performance hydrogen sensors are important in many industries to effectively address safety concerns related to the production, delivering, storage and use of H₂ gas. Herein, we present a highly sensitive hydrogen gas sensor based on SnO₂-loaded ZnO nanofibers (NFs). The xSnO₂-loaded (x = 0.05, 0.1 and 0.15) ZnO NFs were fabricated using an electrospinning technique followed by calcination at high temperature. Microscopic analyses demonstrated the formation of NFs with expected morphology and chemical composition. Hydrogen sensing studies were performed at various temperatures and the optimal working temperature was selected as 300 °C. The optimal gas sensor (0.1 SnO₂ loaded ZnO NFs) not only showed a high response to 50 ppb hydrogen gas, but also showed an excellent selectivity to hydrogen gas. The excellent performance of the gas sensor to hydrogen gas was mainly related to the formation of SnO₂-ZnO heterojunctions and the metallization effect of ZnO.