Hydrogen sensing properties of low-index surfaces of SnO2 from first-principles

The structural, adsorptive and electronic properties of H-2 adsorption on SnO2 are investigated by the first-principles calculations with special focus on four experimentally confirmed surfaces. Calculation results predict that H-2 adsorbed on O-bridging site was the most energetically favorable mode among four low-index SnO2 surfaces. The (1 0 1) surface is found to be more reducible than the other SnO2 surfaces, which is mainly attributed to a new surface states appear near the Fermi level (E-F) and larger charges transfer between H-2 molecule and the (1 0 1) surface. These finding render a careful synthesis of SnO2 crystal so as to form a high orientation of (1 0 1) surface, which will be primarily important for further improve reductive gas sensing performance of SnO2-based sensor. (C) 2010 Elsevier B.V. All rights reserved.