Composites g-C3N4 and BiOIO3 for photocatalytic decomposition of N2O

The composites of graphitic carbon nitride (g-C3N4) and BiOIO3 with different weight ratios of both components (1:1, 2:1, 4:1 and 6:1) were prepared by heating of their mechanical mixtures. Bismuth iodate was prepared by hydrothermal treatment of aqueous solutions of Bi(NO3)3·5H2O and I2O5. Pure g-C3N4 was prepared by thermal polycondenzation of melamine at 620 °C. All of the samples were characterized using X-ray powder diffraction (XRPD), transmission electron microscopy (TEM), high resolution transmission electron microscopy (HRTEM), UV-VIS diffuse reflectance spectroscopy (DRS), photoluminescence (PL) spectroscopy, X-ray photoelectron (XPS) and Fourier transformed infrared (FTIR) spectroscopy. The measurement of photocurrents was used for the study of photogenerated charge carriers and nitrogen physisorption for the evaluation of specific surface area (SSA) and pore size distribution of the samples. The photodegradation activity of the samples was tested by the UVA light photocatalytic decomposition of N2O. The highest photodegradation activity was observed for the 1:1 composite, which was 2 and 2.5 times higher in comparison to pure BiOIO3 and g-C3N4, respectively. The enhanced photocatalytic activity was explained by a significant reduction of charge carriers’ recombination due to the formation of a heterojunction between g-C3N4 and BiOIO3.