Preparation and nitrogen-doping of three-dimensionally ordered macroporous TiO2 with enhanced photocatalytic activity

Three-dimensionally ordered macroporous titanium dioxide (3DOM TiO2) was synthesized through a colloidal crystal template method using self-made poly-(methyl methacrylate) (PMMA) microspheres as a hard template. Nitrogen-doped 3DOM TiO2 (N-3DOM TiO2) samples were also prepared by an impregnation method. The samples were characterized by techniques such as SEM, EDX, XRD, TGA, and UV–visible spectroscopy. The photocatalytic activities of these catalysts were tested by degradation of methyl orange (MO) under UV–visible light and visible light respectively. The experimental results show that the 3DOM TiO2 and N-3DOM TiO2 exhibited improved optical absorption and subsequently enhanced photodegradation efficiency of MO compared to TiO2 particles.