High-response and selective hydrogen sensing properties of porous ZnO nanotubes

• Porous ZnO nanotubes are fabricated by sputtering and thermal calcination process using PVA nanofiber.
• High-response and selective hydrogen sensor is fabricated using ZnO nanotubes.
• ZnO nanotube sensor which have wall of slightly thicker than two times of Debye length reveals best sensing performance.
• .Sensing mechanisms of ZnO nanotube sensor can be explained by surface area, space charge region, and potential barrier.

Hydrogen gas is utilized in various industrial fields, and its utility in modern life is becoming a reality since the development of hydrogen fuel cell vehicles. However, hydrogen gas is extremely explosive at room temperature and requires cautious handling. Herein, a ZnO nanotube sensor was fabricated via a three step process; this sensor exhibited high response and selectively detected hydrogen gas owing to its large surface area and grain boundaries. The response of this sensor was quantified as 139.11 when 1000 ppm H2 gas was supplied to the sensor. A porous ZnO nanotube sensor was fabricated and the mechanism by which enhanced hydrogen sensing is achieved was evaluated.