Fast response hydrogen sensors operating at room temperature based on nanoporous palladium (Pd) films supported by treated anodic aluminum oxide (AAO) template have been demonstrated. It was found that the nanoporous Pd film had a quicker and reversible response by a 30-min pore-widening treatment of the AA0 template, due to its faster absorption and desorption of hydrogen. We obtained a sensor response time as short as 14 s at 1.4% hydrogen concentration with the 30-min pore-widening treatment of AA0 template. The sensor exhibited very good performance at hydrogen concentrations from 0.1% to 2%. (C) 2016 Elsevier B.V. All rights reserved.