removed from the final products and just MgO nanostructures
with physisorbed H2O on the their surfaces exist. The PL spectrum
of the MgO nanostructures is shown in Fig. 4a. The absorption
edge of obtained MgO nanostructures is observed at 376 nm that is
in good agreement with the literature [4]. To evaluate the photocatalytic
decomposition of MB, MgO nanostructures were used as
photocatalyst. For this purpose, the photocatalytic decomposition
of MB as an organic pollutant was done under UV-light illumination
at 25 °C, and the degradation rate for the decomposition of
MB was estimated by observing the changes in absorbance (absorption
intensity vs. irradiation time) obtained by UV–vis spectra.
Fig. 4b shows the plot of the degradation versus time intervals
for the photocatalytic reaction of blank sample, Mg–MOF and MgO
nanostructures. According to Fig. 4b, in absence of MgO nanostructures
(blank sample), almost negligible radiation of MB is
observable while in the presence of MgO, about 90% of MB was
decolorized after 180 min. This result exhibits that our synthesized
MgO nanorods have remarkable photocatalytic activity compared
to Mageshwari et al. [4] that obtained such a degradation efficiency
by utilizing MgO nanoparticles after 300 min.
In comparison with other similar works for synthesizing MgO
[4–7], our thermal decomposition method is facile, low-cost and
low- temperature. To the best of our knowledge, using Mg–MOF as
a starting reagent for synthesizing MgO has not been reported so