Pd nanocrystal sensitization two-dimension porous TiO for instantaneous and high efficient H detection.

Hydrogen (H) molecules are easy to leak during production, storage, transportation and usage. Because of their flammability and explosive nature, quick and reliable dectection of H molecule is of great significance. Herein, an excellent H gas sensor has been realized based on Pd nanocrystal sensitized two-dimensional (2D) porous TiO (Pd/TiO). The formation of 2D porous TiO 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. The Pd/TiO sensor exhibited an instantaneous response and a satisfactory low detection limit for H 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, including the unique adsorption properties of O or/and H on Pd/TiO, the reaction between PdO and H gas, and the regulated depletion layer arising from p-type PdO to n-type TiO. This work demonstrates a rational design and synthesis of highly efficient H sensitive materials for energy and manufacturing security.