Here, we focus on the development of improved technologies for the removal of pollutants from gaseous and liquid effluents and for the treatment and purification of water. Advanced oxidation processes (AOPs) are designed to remove organic contaminants from water and wastewater by chemical reactions involving very reactive and powerful oxidants, and include catalytic wet oxidation, catalytic wet peroxide oxidation, catalytic ozonation and heterogeneous photocatalysis. The catalysts we develop for these AOPs are mostly based on nanostructured carbon materials, alone or combined with semiconducting oxides. The preparation of innovative carbon-based membranes for water desalination and purification applications, eventually combined with AOPs, is a more recent project with promising results. Still in the field of water decontamination, supported bimetallic catalysts have been developed for the catalytic reduction of inorganic ions. Concerning air pollution abatement, our efforts are focused mainly on the development of efficient catalysts (particularly oxide catalysts) for the total oxidation of volatile organic compounds (VOCs), and supported gold catalysts for carbon monoxide oxidation.