Transition metal-doped titania inverse opals: Fabrication and characterization

Transition metal (Fe, Zn, and Cr)-doped titania inverse opals were prepared by infiltrating a mixed precursor composed of tetrabutyl titanate (TBOT) and metal nitrate in the voids of home-made monodispersed polystyrene sphere templates. All obtained products exhibited three-dimensionally ordered macroporous (3DOM) structure and homogeneous wall composition. Fe, Zn, and Cr with broad concentration domains ranging from 1% to 20% were dispersed into the titania inverse opal (TIO) framework while preserving their respective morphology feature. The macropore diameter and frame thickness of transition metal (TM)-doped TIOs are dependent on different metal species doped. The morphology, composition, and optical property of TM-doped TIOs were characterized by scanning electron microscopy, transmission electron microscopy, energy dispersive spectrometer, X-ray photoelectron spectroscopy, X-ray diffraction, and UV/vis absorption spectroscopy.