ie404123f_si_001.pdf (501.36 kB)
Biphase TiO2 Microspheres with Enhanced Photocatalytic Activity
journal contribution
posted on 2014-05-14, 00:00 authored by Sudipto Pal, Anna Maria Laera, Antonio Licciulli, Massimo Catalano, Antonietta TaurinoTiO2 microspheres (TMS) with perfect spherical morphology
were synthesized by spray drying of a hydrothermally cured aqueous
suspension of TiO2 nanoparticles. TiO2 powders
(TP) obtained by drying the nanoparticle suspension were studied simultaneously
to determine which was the most efficient photocatalyst. SEM images
and laser granulometry on TMS show spherical morphology with the diameter
ranging from 2 to 10 μm. TMS had high specific surface area
after annealing as seen from BET analyses. XRD analyses show that
TMS consist of anatase and rutile crystalline phases where the rutile
fraction increases with annealing temperature and above 500 °C
rutile dominates anatase. Raman spectroscopy shows several Raman bands
from anatase and rutile phases and supports the XRD results of phase
transformation with increasing annealing temperature. Photodegradation
of organic pollutants in aqueous solution under UV light irradiation
establishes the higher photocatalytic activity of TMS with respect
to TP. The highest efficiency was found on the 400 °C annealed
TMS.