Waste Pd/Fish-Collagen as anode for energy storage

Because of the huge demand for energy materials, it is paramount to develop practical, low-cost, and renewable energy systems. Until now, batteries made of green materials have either been costly or of limited use. Herein, this paper reports the pioneer utilization of fish waste, doped with Pd nanoparticles (Pd NPs) by incipient wetness impregnation to form Pd/Fish-Collagen. The Pd/Fish-Collagen was first used as a catalyst to abate benzene, and then utilized as anode material in three different rechargeable battery systems; Li-, Na-, and Mg- ion batteries. XRD patterns confirmed that the Fish-Collagen (CaS and CaCO3) was amorphous, while the Pd/Fish-Collagen sample exhibited broad peaks assigned to a mixture of Pd and PdO NPs coexisting with the amorphous Fish-Collagen. TEM and HRTEM images confirmed that the Fish-Collagen and the Pd NPs had average particle sizes of about 70 and 5 nm respectively. The electrochemical properties of the Pd/Fish-Collagen as an anode material in Li, Na, and Mg-based cells showed reversible capacities of 270, 120, and 105 mA h g−1, respectively. The CV and ex-situ XRD tests suggested a pseudocapacitance reaction occurred in Li and Na storage, while the Mg-based cells presented a conversion reaction. This new strategy to generate electrodes from renewable sources is cost-effective and with optimization, millions of tons of this remaining waste can find potential applications in such energy storage systems.