resumo
Water contamination is a serious global problem which requires efforts to guarantee the water supply for future generations. Pharmaceutical wastes are one of the most relevant water pollutants, and conventional wastewater treatment processes are inefficient to their removal. Advanced oxidation processes based on the use of photocatalysts emerge as a viable alternative for these persistent pollutants. This research work is focused on different carbon-based materials of distinct structural dimensionalities, including graphene oxide and other graphene-based materials, carbon microspheres and carbon dots. Graphene-based materials and carbon microspheres were used as growth platform for different crystalline semiconductor phases, such as metal sulfides and bismuth vanadate with the main goal of developing multicomponent heterogenous photocatalysts activated by visible-light irradiation. The developed hybrid materials were further tested in the photocatalytic degradation of an organic dye (rhodamine B) and two pharmaceutical compounds (sulfamethoxazole and tetracycline), and their photodegradation mechanism was studied. A crucial aspect in developing such hybrid photocatalysts combining distinct functionalities is understanding their surface chemistry. In this work, this objective was explored through surface chemical modification routes for different carbon materials. Lastly, exploratory research was performed on the optical properties and surface chemistry of carbon dots prepared from carrageenan, a renewable carbon source.
autores
Joana L. Lopes
nossos autores
Joana Lúcia Marto dos Santos Lopes
Estudante de doutoramentoorientadores
Tito Trindade; Ana C. Estrada