TiO x Porous Electrodes for Wastewater Treatment by Electrooxidation: From Materials Science and Proof of Concept to Environmental Applicability

Data presented in the literature have demonstrated that porous TiO x electrodes can combine a relevant reactivity for electrooxidation of organic pollutants while achieving a real shift in the order of magnitude of mass transport rates. This material presents numerous opportunities, particularly for the treatment of low pollutant concentrations, which is a critical aspect of the quaternary treatment of urban wastewaters and poses significant technical and environmental issues. The development of efficient, robust, and scalable electrodes is a key challenge, requiring a multidisciplinary approach that combines expertise in material synthesis and characterization, a thorough understanding of interfacial electrochemical phenomena, thoughtful reactor design, in-depth knowledge of water chemistry in complex matrices, and a clear definition of treatment goals. This review aims to start bridging the gap between the science and engineering of porous TiO x materials and their application in wastewater treatment. The state-of-the-art related to this technology, along with a comparison to competing technologies in terms of performances, such as OPEX and CAPEX, allows for the identification of a roadmap to further advance this innovative process.