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 H-2 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. (C) 2016 Elsevier B.V. All rights reserved.