In the present paper, we report novel room-temperature hydrogen sensors based on palladium oxide (PdO) loaded tungsten oxide (PdO-WO3) nanohybrids. We synthesized WO3 nanorods by hydrothermal method. Then the as-synthesized nanorods were mixed into PdCl2 solution with a subsequent thermal treatment to form PdO-WO3 nanohybrids. XRD and XPS test confirmed that PdO-WO3 nanohybrids were successfully prepared. FE-SEM and HRTEM images showed that PdO nanoparticles were distributed on the surface of WO3 nanorods in the nanohybrids. UV Vis spectra indicated that broader visible light absorption range of PdO-WO3 composites was obtained when compared with that of pure WO3. The obtained PdO-WO3 sensors exhibited good responses to ppm-level H-2 gas at room temperature under visible light illumination, and the best sensing performance was achieved upon exposure to blue light illumination. The best sensing performance was comparable to the counterpart performed at an elevated temperature between 200 and 250 degrees C. (C) 2016 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.