Structure and photocatalytic activity of composites of semiconducting nanoparticles in polymethylmethacrylate

We fabricated and studied composites made of titania (TiO2), zinc oxide (ZnO) or graphitic carbon nitride (g-C3N4) nanoparticles (20–100 nm) in polymethylmethacrylate (PMMA). Nanodispersed powders of these semiconductors were mixed with mechanically grinded PMMA at a weight ratio ranging from 1 : 5 to 1 : 20. The mixture was dissolved in acetone and deposited on to the surface of water. Upon solidification and drying in air porous discs as thick as 50–200 μm were formed. They were found to have a mechanical durability at the semiconductor to PMMA ratio above 1 : 20. Scanning electron microscopy, energy dispersive x-ray spectroscopy, x-ray difractomenry of the samples demonstrated that semiconducting nanoparticles are quasiuniformly distributed in the polymer matrix. Their crystal structure, the particle size and the composition do not change in comparison to those before synthesis of the composites. Photocatalytic activity of the synthesized composites estimated by decolarization of water solution of the test dye (methylene blue) under UV irradiation was found to be reduced in the sequence TiO2, g-C3N4, ZnO.