Application of TiO2 photocatalysts hybridized with carbonaceous for degradation of pharmaceuticals

Abstract Emerging contaminants are pollutants that are not commonly monitored and that still require studies to determine their harmfulness. These compounds are often recalcitrant and resistant to biological treatment. Among this class of substances, pharmaceuticals have great representativeness, causing harmful effects even at concentrations in the order of nanograms. Conventional physical-chemical treatments do not guarantee the total removal of these contaminants. For this reason it is necessary to develop complementary techniques to assist in the treatment of wastewater. Photocatalysis can be a promising and environmentally friendly alternative for the treatment of emerging contaminants. However, the main semiconductors used as photocatalysts still depend on the use of UV irradiation as a form of activation, making the process more expensive and hampering its large-scale application. Among the strategies developed to increase the efficiency of photocatalysts is the doping of this material with metals and nonmetals, to reduce the band gap of the photocatalysts. This measure makes it possible to use solar energy to activate photocatalysts. The modification of metallic oxides with carbonaceous materials has gained visibility in recent years. This is because, depending on the structure used, it is possible to obtain properties of interest, capable of increasing the efficiency of the photocatalyst when compared to its isolated form. This chapter proposes to present recent research on the synthesis of hybrid photocatalysts, combined with different forms of carbon (activated carbon, doping with carbon, nanotubes and graphene) with potential application in the degradation of emerging contaminating pharmaceuticals.