Synthesis, characterization, and application of MgO/ZnO nanocomposite supported on activated carbon for photocatalytic degradation of methylene blue

In this study, nano-sized ZnO/MgO composites at different ratios were synthesized based on sol-gel method under ultrasonic radiation, and then combined with as-prepared activated carbon (AC). The prepared materials were characterized by transmission electron microscopy, scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectrometry, and Brunauer-Emmett-Teller surface area measurements. The photocatalytic activity of the prepared nanocomposites was tested on the decolorization of methylene blue (MB) aqueous solutions. The dye photo-decolorization process was studied considering the influence of experimental parameters such as catalyst concentration, ZnO/MgO/AC ratio, pH, and MB adsorption rate. The resulting material composition with the best catalytic activity towards the MB photo-decolorization was ZnO doped with 10 % MgO and 10 % AC. The complete photo-oxidation of a 1 x 10(-5) mol l(-1) MB solution, at natural pH and room temperature, was achieved in <20 min, nearly 60 min faster than the ZnO photo-assisted process. Experimental results show that ZnO/MgO/AC nanoparticles possess high photocatalytic activity in comparison with universal catalysts.