Hydrogen sensors with fast response and recovery rate based on nanoporous palladium (Pd) and titanium dioxide (TiO2) composite films supported by anodic aluminum oxide (AAO) template have been demonstrated. Nanoporous TiO2 film was sprayed on the porous AAO templates, followed by Pd film deposited on TiO2 layer by DC magnetron sputtering. We have researched the detection performance of the hydrogen sensors depending on different thickness of TiO2 layer from 6 to 30 nm with keeping the thickness of Pd as 30 nm. The results have demonstrated the sensors with 10 nm thickness of TiO2 achieve the best performance with a response/recovery time as short as 4/8s at 0.8% and 0.4% hydrogen concentration, respectively. The sensors exhibited very good performance under hydrogen concentrations from 0.4% to 1.8%. (C) 2018 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.