2. Experimental
2.1. Chemicals and reaction apparatus
All of the chemicals were of analytical grade or reagent
grade without further purification except thermal sensitizer
(Mn–Si–Ca–Cu–Ni complex oxides synthesized by high temperature
calcination, considered as thermal catalyst, details in Table 1).
Methylene blue (MB) dye was performed to the corresponding
solutions of desired concentrations. Deionized and doubly distilled
water was employed throughout the experiment. The different pH
values of the reaction solutions were adjusted by adding diluted
HCl or NaOH solutions (both 0.05 M) at room temperature.
Experiments were carried out in a reaction apparatus. The
schematic diagram is shown in Fig. 1. The absorbances of various
concentrations for MB solutions were recorded by using Ultraviolet
Visible (UV–vis) spectrometer. In all cases, when the measured