Following the growth of ZnO clusters on graphite by in situ X-ray Absorption Near-Edge Spectroscopy

This work reports on time-resolved in situ X-ray Absorption Near-Edge Spectroscopy (XANES) investigation at the Zn K-edge during the hydrothermal synthesis of ZnO structures on graphite. Such challenging and scarcely explored experiment enabled to monitor the evolution of Zn chemical species during the film deposition, from Zn+2 ions in solution to solid ZnO. In addition, other experimental techniques were applied to better comprehend the formation and growth of the ZnO. For instance, scanning electron microscopy (SEM) was used to track the morphological changes at different deposition stages, and XRD (X-ray diffraction) provided the long range structural order. XPS (X-ray photoelectron spectroscopy) analysis, excited with synchrotron radiation, allowed probing the composition and electronic structure of the resulting ZnO structures. Diaminopropane concentration turns out to be an essential parameter of the synthesis reaction, and its influence on the ZnO morphology was evaluated. (c) 2018 Elsevier Ltd. All rights reserved.