A fast and low-cost sol-gel synthesis used to deposit a shell of TiO 2 anatase onto an array of vertically aligned ZnO nanowires (NWs) is reported in this paper. The influence of the annealing atmosphere (air or N 2) and of the NWs preannealing process, before TiO2 deposition, on both the physicochemical characteristics and photoelectrochemical (PEC) performance of the resulting heterostructure, was studied. The efficient application of the ZnO@TiO2 core-shells for the PEC water-splitting reaction, under simulated solar light illumination (AM 1.5G) solar light illumination in basic media, is here reported for the first time. This application has had a dual function: to enhance the photoactivity of pristine ZnO NWs and to increase the photodegradation stability, because of the protective role of the TiO2 shell. It was found that an air treatment induces a better charge separation and a lower carrier recombination, which in turn are responsible for an improvement in the PEC performance with respect to N2-treated core-shell materials. Finally, a photocurrent of 0.40 mA/cm2 at 1.23 V versus RHE (2.2 times with respect to the pristine ZnO NWs) was obtained. This achievement can be regarded as a valuable result, considering similar nanostructured electrodes reported in the literature for this application. © 2014 American Chemical Society.
Optimization of 1D ZnO@TiO2Core–Shell Nanostructures for Enhanced Photoelectrochemical Water Splitting under Solar Light Illumination / Hernández, Simelys; Cauda, Valentina; Chiodoni, Angelica; Dallorto, Stefano; Sacco, Adriano; Hidalgo, Diana; Celasco, Edvige; Pirri, Candido. - In: ACS APPLIED MATERIALS & INTERFACES. - ISSN 1944-8244. - 6:15(2014), pp. 12153-12167. [10.1021/am501379m]
|Titolo:||Optimization of 1D ZnO@TiO2Core–Shell Nanostructures for Enhanced Photoelectrochemical Water Splitting under Solar Light Illumination|
|Data di pubblicazione:||2014|
|Digital Object Identifier (DOI):||http://dx.doi.org/10.1021/am501379m|
|Appare nelle tipologie:||1.1 Articolo in rivista|
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