Background: In recent years, pharmaceutical pollutants have emerged as a growing threat
to the environment. To mitigate this situation, heterogeneous photocatalysis has been considered a
promising advanced oxidation technology, where TiO2-based systems have exhibited outstanding efficiency
in the degradation of organic compounds.
Objective: In this work, we have studied the photocatalytic performance of the coupled g-C3N4/TiO2
system in the degradation of the pharmaceuticals tetracycline, ciprofloxacin, and ibuprofen. Moreover,
the effect of the graphitic carbon nitride (g-C3N4) was examined through the study of two different
samples, a bulk g-C3N4 prepared from the direct calcination of melamine and a mesoporous g-C3N4
synthesized through a nanocasting process using SBA-15 silica as hard template.
Methods: The hybrid photocatalysts were prepared by forced hydrolysis of titanium isopropoxide using
two g-C3N4 samples, a bulk material and a mesoporous one. The samples were characterized by
X-ray powder diffraction (XRD), Diffuse Reflectance Spectroscopy (DRS), Fourier-Transform Infrared
Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), and N2 adsorption-desorption measurements.
The photocatalytic activity was examined through the degradation of tetracycline, ciprofloxacin,
and ibuprofen under simulated solar irradiation.
Results: The textural properties of g-C3N4 play a preponderant role in the photoactivity of the g-
C3N4/TiO2 system. In this sense, high dispersion of the TiO2 nanoparticles could be obtained using a
mesoporous g-C3N4 sample. All hybrid photocatalysts exhibit higher degradation rates than the pristine
materials, including bare TiO2. In this regard, the samples with 1 wt.% g-C3N4 attained the highest
photocatalytic performance in the degradation of tetracycline, ciprofloxacin, and ibuprofen.
Conclusion: The coupling of TiO2 with graphitic carbon nitride leads to the formation of hybrid photocatalysts
with outstanding photoactive properties in the degradation of pharmaceutical pollutants. In
this way, the g-C3N4/TiO2 samples can be considered as excellent photocatalysts for the degradation
of organic pollutants.