| Abstract |
: |
This paper deals with doping TiO2 with sulfur powder by sol–gel method, in order
to extend the photocatalytic activity under visible light exposure. Weigh of the sul-
fur powder was varied as 5, 10, and 20 mg doped into 12.5 mmoles of TTIP, (the-
oretically the same as 100 mg of TiO2) to get 5%, 10%, and 20% of S contained
in the prepared TiO2–S. The S-doped TiO2 prepared was characterized by specular
refectance UV–Visible, X-ray difraction, Fourier Transform Infrared, and Scan-
ning Electron Microscope instruments. The efect of S doping on TiO2 photocata-
lytic activity was examined through photo-oxidation of Pb(II) under visible light.
In order to obtain the highest photo-oxidation of Pb(II), optimization of S content,
photocatalyst mass, reaction time, and solution pH were conducted by batch experi-
ment. The results of the research assign that sulfur from the powder has been suc-
cessfully dopped into TiO2, which has signifcantly decreased the band gap ener-
gies and enhanced its activity under visible light. The enhancement was found to be
controlled by the amount of S doped and the highest activity was shown by 10% of
S doped. Furthermore, the most efective removal of Pb(II) 10 mg/L, (~98%), could
be reached by employing 500 mg/L of the TiO2-S (10) dose, 45 min of the time, and
the solution pH at 7. The Pb(II) removal is due to the photo-oxidation induced by OH radicals to form the handleable PbO2. |
