Correlation Of H Adsorption Energy And Nanoscale Elastic Surface Strain On Rutile Tio2(110)

Scanning tunneling microscopy (STM) has been used to obtain the aerial distribution of bridge-bonded hydroxyl groups (HOb) on a ruffle TiO2(110) surface, modified with a well-defined nanoscale strain field. Our study makes use of earlier findings that 5-30 nm wide locally strained areas of the surface can be formed via low-energy Arion bombardment combined with a thermal treatment. These strained areas appear as protrusions in the STM images, resulting from subsurface argon-filled cavities. our STM images show that the local surface concentration of OHb groups is lower on the protrusions. This lowering of concentration has been interpreted as a reduction in the local H absorption. energy, Delta E, a result similar to that observed on metals. In this paper, analysis of the reduction in this O-H bond energy-across the surface shows a strong correlation between Delta(EOH) and the characteristic surface strain Value, S. The Delta E-OH values have been calculated through a subtraction of the contribution of the repulsive dipole dipole interaction between OHb groups. This interaction has been estimated from an analysis of the radial distribution of OHb pairs in the STM images. The measured linear relation between the reduction in O-H bond energy and the surface strain has been estimated to be Delta E-OH (meV)approximate to 11.S (%).