Hydrogen evolution coupled with microplastic upcycling in seawater via solvent-free plasma F-functionalized CoNi alloy catalysts

The deleterious impacts of marine polyethylene terephthalate (PET) microplastic pollution on aquatic organisms have garnered global concern. Crafting a more cost-effective method to derive high value-added products from these microplastics is a pivotal challenge in marine resource reuse. This study introduces a strategy for electrooxidation of PET microplastics coupled with seawater electrolysis for green hydrogen production, resulting in value-added chemical formic acid at the anode and hydrogen gas at the cathode. Specifically, a catalyst composed of carbon nanotube-interconnected CoNi alloy-loaded carbon nanocages was fabricated, and F were doped onto the catalyst surface via solvent-free CF4 plasma treatment. Owing to its unique hollow 1D/3D interconnected structure, the synergistic effect of the CoNi alloy, and the ease of reconstruction of metal-F bonds in an alkaline environment, the prepared electrocatalyst exhibited excellent performance in the hydrogen evolution reaction, oxygen evolution reaction, and electrooxidation of PET microplastics. The proposed coupling strategy achieved a potential saving of 200 mV at a current density of 10 mA cm-2. This research offers promising prospects for the development of “marine hydrogen mining” and the management of ocean microplastics.