Synthesis, characterization, and photocatalytic activity of CuAl2O4–Ag nanocomposite for water treatment

A novel copper aluminate-silver (CuAl2O4–Ag) nanocomposite was synthesized through an organic acid-assisted sol-gel method. Organic acid plays an important role as a chelating agent, reducing agent, and capping agent in synthesizing multicomponent nanocomposites. The photocatalytic performance of the synthesized CuAl2O4–Ag nanocomposite was studied for the degradation of methylene blue under visible light illumination. The products were characterized via Fourier-transform infrared spectroscopy, scanning electron microscope, X-ray diffraction, transmission electron microscope, and UV–Visible spectroscopy. The XRD results showed that crystalline Ag and CuAl2O4 are formed in the samples after calcination at 800 °C. The findings indicated that the crystallite size and average particle size increase by increasing Ag concentration. Nanocomposites containing 3 wt% Ag (CuAl2O4-3wt.%Ag) revealed the maximum photocatalytic yield (97%) and suitable structural stability after several uses. The mechanism of dye photodegradation was discussed. Photocatalytic tests by adding trapping agents revealed that methylene blue photodegradation in this system occurs through photogenerated holes and superoxide radicals.