Abstract:
In textile industries, different types of dyes are used widely. Widespread use of these dyes
causes surface and ground water contamination. This contaminated water is harmful for the
human beings and other organisms as well. Therefore, treatment of this contaminated water is
important. These dyes can be removed from wastewater by using biodegradation but this
method doesn’t remove these dyes completely. Photodegradation has proved really successful
in converting these toxic compounds to non-toxic or less toxic compounds e.g. CO2 and H2O.
This work emphasizes on photodegradation of rhodamine B using TiO2 based photocatalysts.
In this work, nanoparticles of pure and doped TiO2 were synthesized by sol-gel method. For
the synthesis of TiO2 nanoparticles, TTIP (Titanium tetraisopropoxide), 2-propanaol and
distilled water were used. Whereas, for nitrogen and copper doping, urea and copper acetate
were used along with TTIP, 2-propanol and distilled water. The samples were characterized
by SEM, EDX, XRD, UV-vis DRS and FTIR. Band gap of doped catalysts were found to be
low as compared to pure TiO2 which makes doped photocatalysts more suitable for
photocatalytic degradation. The photocatalytic activity of N/Cu-TiO2 catalyst was higher than
pure and nitrogen doped TiO2 for degradation of rhodamine B. Highest degradation efficiency
was achieved with 1% Cu-TiO2 among all copper doped catalysts (0.1% Cu-TiO2, 0.25% Cu-
TiO2, 0.5% Cu-TiO2 and 0.75% Cu-TiO2) that was 88%. So, it was further codoped with
nitrogen and checked its efficiency for degradation of rhodamine B. Results reveal that the
codoped catalyst gives better results than its precursor i.e. 96% degradation was achieved.
Different conditions of degradation experiments were optimized. The best catalytic activity of
the photocatalyst was achieved at 50 mg catalyst dosage, 10 ppm concentration of the analyte
and pH 4. Reusability of the photocatalyst was checked for up to 4 runs and it was observed
to decrease from 96% to 84%.
