High performance H₂ sensors based on NiO-SnO₂ nanosheets in temperature-pulsed operation mode

Enhancements in the responses of semiconductor gas sensors for hydrogen (H₂) are imperative to ensure the safety for industrial processes and fuel cells applications. Alternative to the conventional method of maintaining an optimum isothermal temperature, this study presents a novel technique that sequentially modulates the physisorption and chemisorption processes of the target gas and oxygen species through a temperature-pulsed strategy. This method substantially amplified the electrical responses of a NiO-doped SnO₂ gas sensor to H₂ vapor. Under the optimum pulsed-heating condition, the sensor achieved a remarkable response of 252–300 ppm H₂, which is comparable to or better than that of many existing H₂ sensors. The integration of a pulse-driven microheater with a heterojunction-forming sensing layer has led to improved sensitivity, providing additional opportunities for H₂ monitoring.