Pd nanocrystal sensitization two-dimension porous TiO2 for instantaneous and high efficient H2 detection

Hydrogen (H 2 ) molecules are easy to leak during production, storage, transportation and usage. Because of their flammability and explosive nature, quick and reliable dectection of H 2 molecule is of great significance. Herein, an excellent H 2 gas sensor has been realized based on Pd nanocrystal sensitized two-dimensional (2D) porous TiO 2 (Pd/TiO 2 ). The formation of 2D porous TiO 2 with the removal of graphene oxide template has been monitored by an in-situ transmission electron microscope. It is found that the size of the GO template can be almost completely replicated by 2D TiO 2 . The Pd/TiO 2 sensor exhibited an instantaneous response and a satisfactory low detection limit for H 2 detection. These excellent gas-sensing performances (good selectivity, unique linearity response and high stability) can be attributed to the unique 2D porous structure and the synergistic effect between oxidized Pd and TiO 2 , including the unique adsorption properties of O 2 or/and H 2 on Pd/TiO 2 , the reaction between PdO and H 2 gas, and the regulated depletion layer arising from p-type PdO to n -type TiO 2 . This work demonstrates a rational design and synthesis of highly efficient H 2 sensitive materials for energy and manufacturing security.