Modifying Gas Diffusion Electrode with Food Waste-Derived Materials for Enhancing Electrochemical Conversion of CO₂

The disposal of organic wastes from food sources contributes to undesirable environment impact and the loss of valuable resources. These food wastes usually end up in incineration plants or landfills, which could result in the unintended release of greenhouse gases. Considering that the global population is expected to reach over 9 billion in 2050, the demand of food resources, and thus the production of food waste will increase. Therefore, there is a need to develop strategies to upcycle food wastes toward valuable materials to maximize the utilization of resources while minimizing the environmental impact. In this study, we demonstrated the fabrication of gas diffusion electrodes integrated with food waste-derived materials for the electrochemical conversion of CO₂ to CO. By using commercial Ag nanoparticles as electrocatalysts, the incorporation of the as-prepared food waste-derived materials enhanced the maximum production rate of CO by 48%. At the same time, the faradaic efficiency of CO was improved by 28% at an applied potential of −1.1 V vs RHE. The materials derived from food wastes were shown to improve the conductivity of the gas diffusion electrode, which facilitated the charge transfer between the electrocatalysts to the reactants. This work thus represents an approach to avoid greenhouse gas emissions by valorizing food waste into functional materials, which further enable a more efficient conversion of CO₂ to useful chemicals.