Renewable Energy from Livestock Waste Valorization: Amyloid-Based Feather Keratin Fuel Cells

Abstract Increasing carbon emissions have accelerated climate change, resulting in devastating effects that have become tangible on an everyday basis 1 . This is mirrored by a projected increase in global energy demand by ca. 50% in a single generation timespan 2,3 , urging a shift from fossil-fuel derived materials toward greener materials and more sustainable manufacturing processes 4 . Bio-based industrial byproducts, such as food industry side-streams 5 , are attractive alternatives with a strong potential for valorization owing to their large volume, low cost, renewability, biodegradability, and intrinsic material properties 6 . Here we demonstrate the reutilization of industrial chicken feathers waste into proton conductive membranes for fuel cells 7 , protonic transistors 8 , and water-splitting devices 9 . Keratin was isolated from chicken feathers via a fast and economical process, converted into amyloid fibrils upon heat treatment, and further processed into membranes with imparted proton conductivity through a simple oxidative method 10 . The functionality of the membranes is demonstrated by assembling them into a hydrogen fuel cell capable of powering several types of devices using hydrogen and air as fuel. Additionally, these membranes could be used to generate hydrogen by water splitting, and in protonic field-effect transistors as a thin-film modulating protonic conductivity via the electrostatic gating effect. We believe that by converting industrial waste into renewable energy materials at low cost and high scalability, our green manufacturing process can contribute to a fully circular economy with neutral carbon footprint.