Comparison of different methods for the synthesis of ZnO based nanocomposites and investigation of photocatalytic degradation of Direct Red 23

In this work, the photocatalytic degradation of organic dyes was studied employing zinc oxide based nanocomposites. In this purpose, ZnO based nanocomposites were synthesized using three different procedures including co-precipitation, hydrothermal and combustion methods. The samples were characterized by SEM, XRD, IR and UV-Vis spectrophotometer. Afterwards, the prepared samples were utilized for the photocatalytic degradation of Direct Red 23 (DR23). The effect of operational parameters containing photocatalyst amount, time, pH and dye concentration were investigated as effective factors on photocatalytic degradation process. The results represented that the particles synthesized by combustion method was the appropriate one for the decolorization of DR23. In this regards, the decolorization percentage of 97.5% was attained using 0.08 g photocatalyst and dye concentration of 20 mg L-1 after 120 min.