An organometallic approach for the preparation of Au-TiO2 and Au-g-C3N4 nanohybrids: improving the depletion of paracetamol under visible light.

The photocatalytic degradation of paracetamol (a common analgesic also known as acetaminophen) in ultrapure water with different photocatalytic systems was performed under ultraviolet or visible irradiation. The photocatalysts employed were: commercial Degussa-P25 TiO2 and Au-TiO2 under UVA irradiation (365 nm) and g-C3N4 and Au-g-C3N4 under visible light irradiation (low-power (4 × 10 W) white light LEDs), improving the effectiveness of degradation rates when the gold nanoparticles (Au NPs) were combined with the semiconductors. The nanostructured photocatalysts were synthesised and characterised by transmission electron microscope (TEM), UV-vis diffuse reflectance spectroscopy and, in the case of g-C3N4 photocatalysts by X-ray photoelectron spectroscopy (XPS). The influence of the pH in the depletion of paracetamol with g-C3N4 and visible light was evaluated. In addition, the stability and lifetime of the photocatalyst g-C3N4 in the degradation of paracetamol were studied.