1 research outputs found
Optimization of 1D ZnO@TiO<sub>2</sub> CoreāShell Nanostructures for Enhanced Photoelectrochemical Water Splitting under Solar Light Illumination
A fast
and low-cost solāgel synthesis used to deposit a shell of TiO<sub>2</sub> anatase onto an array of vertically aligned ZnO nanowires
(NWs) is reported in this paper. The influence of the annealing atmosphere
(air or N<sub>2</sub>) and of the NWs preannealing process, before
TiO<sub>2</sub> deposition, on both the physicochemical characteristics
and photoelectrochemical (PEC) performance of the resulting heterostructure,
was studied. The efficient application of the ZnO@TiO<sub>2</sub> coreāshells
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 TiO<sub>2</sub> 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 N<sub>2</sub>-treated coreāshell
materials. Finally, a photocurrent of 0.40 mA/cm<sup>2</sup> 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