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

Abstract

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.

Recent Advances and Challenges of Nanomaterials-Based Hydrogen Sensors

“…However, like some SnO2-based gas sensors, many ZnO gas sensors require high operating temperature (up to 400 °C) in sensing applications, which causes high power consumption and thus leads to instability during long-term gas detection. Therefore, more thoughtful strategies were developed to enhance their sensitivity and selectivity with lower power consumption [107,[121][122][123][124][125][126][127]. Another widely used metal oxide semiconductor is ZnO, an n-type semiconductor with a bandgap of 3.37 eV.…”

“…This kind of plasma-treated sensor can detect the H 2 concentration down to 10 ppm. Lee et al controlled the content of SnO 2 in their SnO 2 /ZnO heterojunction hydrogen gas sensor and reported in their paper [127] that the sensors with the xSnO 2 -loaded (x = 1) ZnO nanofiber also exhibited a high response (R a /R g = 50.1) to 50 ppb hydrogen at 300 • C. Furthermore, this kind of sensor showed an excellent selectivity towards the hydrogen gas sensor.…”

MOSFE-Capacitor Silicon Carbide-Based Hydrogen Gas Sensors

“…In [ 18 ], the chemo-resistive nanocomposite NiO:Pd sensor capable of detecting Hydrogen concentrations in the air up to 300 ppb and operating in the temperature range of 115–145 °C was described. In [ 19 ], the best 50 ppb Hydrogen LOD result that we could find in the literature is presented: a gas sensor based on SnO 2 -loaded ZnO nanofibers fabricated using an electrospinning technique with optimal working temperature of 300 °C.…”

Recent Advances in Photo−Activated Chemical Sensors

“…On the other hand, these detectors suffer cross−sensitivity with other gases; high reactivity with gases other than the target gas reduces selectivity [ 75 , 76 , 77 ]. Furthermore, the demand for faster recovery rates [ 78 , 79 , 80 ] and improved responsiveness in detecting extremely small amounts of gas [ 81 , 82 , 83 , 84 ] is driving the continuous development of these detectors. As an emerging approach, photo−activated or photo−assisted gas detection over diverse materials and devices has been proposed.…”