Interaction of hydrogen with ZnO nanopowders—evidence of hydroxyl group formation

Abstract

There have been many investigations to reveal the nature of the hydrogen gas and ZnO nanopowder interaction at elevated temperatures, while at present no conclusive description of such an interaction has been confidently reported. In this work, we demonstrate that a hydroxyl group is formed during this interaction, depending on size and relative crystallinity of nanopowders. Our in situ Raman spectroscopy investigations show that the interaction directly affects the intensity of the Raman signal at 483 cm(-1), relative to the peak at 519 cm(-1). Ex situ x-ray diffraction (XRD) and infrared spectroscopy also show extra peaks at 44° and 1618 cm(-1), respectively, after hydrogenation. These peaks were all identified as surface hydroxyl groups, which can be related to the formation of water on the ZnO nanopowder surfaces.

CH3CH2OH, CD3CD2OD, and CF3CH2OH Decomposition on ZnO $$ \left( {1\bar{1}00} \right) $$ 1 1 ¯ 00

“…These observations suggest that adsorbed H atoms can reduce the surface and extract lattice O atoms to yield H 2 O. This step is consistent with formation of surface OH species from adsorbed H that has been observed through vibrational spectroscopies and linked to H 2 O formation from ZnO [19][20][21].…”

Bottom‐Up Nano‐heteroepitaxy of Wafer‐Scale Semipolar GaN on (001) Si

“…It can be seen that the E 2 ‐high peak appears at 568.9 cm −1 after 20 min of the low‐temperature nucleation (Stage 1), corresponding to a stress‐free state . A minor peak at 549.3 cm −1 is also observed in the same spectra, which is ascribed to the signal from the ZnO nanorods . The GaN phonon peak then shifts to lower wavenumbers with increased layer thickness, indicating the buildup of tensile stress as the lateral coalescence of GaN proceeds among the nanorods.…”

Study of hydrogen generation and radionuclide release during wet damaged oxide spent fuel storage

“…It must be noted that as of today, the existence of this reaction has not been proven. It has been reported that H2 can undergo homolytic dissociation on dry surfaces [88][89][90] but this process has yet to be observed in aqueous chemistry.…”