Proton dynamics in ZnO nanorods quantified by in situ solid-state 1H nuclear magnetic resonance spectroscopy

In situ solid-state H-1 NMR spectroscopy was employed to investigate the local chemical environments and dynamic details of protons in ZnO nanorods. The mean correlation time for the 4.8 ppm resonance was found to be similar to 2.1 x 10(-10) s at 500 K and the activation energy for proton hopping was similar to 0.15 eV. Both the small activation energy and short correlation time suggest that the protons are mobile. In contrast to nanometer micrometer particles of ZnO, gamma-Al2O3, and CeO2, a stable resonance at 4.8 ppm indicates that these proton species are most likely associated with the defect sites in the lattice of ZnO nanorods. (C) 2007 American Institute of Physics.