CuO- and Ag2O-decorated g-C3N4 photocatalysts were prepared by appropriate chemical modification of carbon nitride nanosheets produced from programmed pyrolysis of urea. After comprehensive characterization by powder X-ray diffraction, diffuse reflectance spectroscopy, Fourier transform–infrared spectroscopy, scanning electron microscopy, and Brunauer–Emmett– Teller analysis methods, their photocatalytic performances were examined for the removal of Acid Blue 92 azo dye, as a typical wastewater component from the textile industry. The X-ray diffraction patterns confirmed the presence of CuO and Ag2O nanoparticles on the surface of the sheets. In addition, diffuse reflectance spectra indicated a considerable reduction of the band gap of pure C3N4 by modification. The photoreaction was discussed mechanistically and the best operational parameters were found to achieve the highest efficiency under visible light.
