NOVELTY - Electrode (E1) comprises graphenes or their mixture (at least 30 wt.%) and other non-nanostructured carbon-based materials containing graphemes (at least 80 wt.%).    USE - For electrochemical reactions, preferably in electrooxidation process for the removal of organic and inorganic contaminants from a liquid waste; and also used in galvanic processes, dye-sensitized solar cells (DSSCs), electroflotation for wastewater treatment, or production and storage of energy in batteries and fuel cells (claimed).    ADVANTAGE - The use of anodes in electrooxidation processes avoids both the problem of wear of the anodes and the consequent formation of sludge, which has so far hindered the spread of the technique. The anodes are the electrodes having the following properties: high electrical conductivity; high production of H2, with a volume percentage in the gas usually in 15-35 vol.%; ozone production during the process that enhance the process of chemical oxidation; they limit the pH variations during the process; they function as catalysts for the entire process: no electrode corrosion process occurs at the anode; they constitute the absorbent and reagent medium in terms of surface; they facilitate removal of COD, BOD5, heavy metals, chromium, boron, nitrogen containing compounds and ammonia; no sludge or sediments form in the process cell; and formation of products with high oxidizing power. In the case of electrooxidation processes, the electrode shows an efficiency in terms of contaminant removal 3 times higher if compared with electrodes made of carbon-based nanostructured materials, particularly nanotubes, fullerenes or their mixtures; the difference in efficiency is even more marked with respect to non-nanostructured carbon based materials.    DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for electrooxidation process for the removal of organic and inorganic contaminants from a liquid waste, involving letting electric current pass between at least an anode and at least a cathode immersed in the liquid to be treated, where the anode is the electrode (E1).