Fabrication of a Sustainable Closed Loop for Waste-Derived Materials in Electrochemical Applications

Innovation in the field of electrochemistry usually depends on the development of new electrodes, which are still based on natural resource consumption. Until recently, little work focused on the green and sustainable development of electrochemical materials. In this work, we put forward a closed-loop strategy for utilization of biowastes and industrial solid wastes in electrochemical applications. In order to obtain effective electrochemical catalysts, waste components and structures had to be regulated. If one biowaste was used to produce the electrode, the focus was generally put on controlling a specific surface area, pore size distribution, graphitization degree, and surface chemical characteristics. As for one industrial solid waste, controlling factors were metal doping and morphology/crystallinity. After one metal–carbon hybrid was combined by the above two wastes, it was transformed to metal oxide again by thermal treatment. Similarly, the obtained oxide combined with biowaste again to form another hybrid. A closed loop was thus fabricated. After all, waste-derived materials showed reasonable electrochemical performances, which were in favor of developing a "zero-waste" concept.