Electrochemistry as an interface for nanotechnology-enhanced water treatment and resource recovery

The advent of engineered nanomaterials and architectures hold promise of an unprecedented performance in removing persistent chemicals and recovering resources from water. Nanostructured electrodes can be designed to entail a large specific surface area and tunable properties, which allow tailoring of the electrocatalytic surface to enhance the reactions with specific contaminants. In the scope of the European Research Council (ERC) Starting Grant project ELECTRON4WATER, we developed graphene- and metal-based nanostructured electrodes for electrochemical water treatment and resource recovery. We developed graphene sponge electrodes capable of degrading highly persistent pollutants such as per- and polyfluoroalkyl substances (PFAS), as well as other organic and microbial pollutants. This is achieved while overcoming a major bottleneck of electrochemical water treatment – formation of toxic chlorinated byproducts, as graphene sponge anode does not form any chlorate and perchlorate even in the presence of high chloride concentrations (>1 g/L), and displays very low current efficiency (i.e., <0.1%) for the generation of chlorine. The estimated cost of their bottom-up synthesis is two orders of magnitude lower compared with the commercial electrodes. First scalable graphene-enabled electrochemical systems were developed within an ERC Proof of Concept Grant GRAPHEC and will be further upscaled and commercialized within a European Innovation Council (EIC) Grant FOREVER WATER. Furthermore, our group is currently developing functionalized monolith electrodes for electrochemical recovery of lithium and other critical raw materials (CRMs) from industrial waste streams, in the scope of ERC Consolidator Grant ELECTROmonoLITH. Through different technologies and projects developed in our group, this presentation will illustrate the significance of nanotechnology in the development of high-performing, cost-effective, and environmentally friendly water treatment and resource recovery technologies.