Co-pyrolysis of two environmental issues: Face mask and Sargassum spp. for efficacious solid waste management and its AEMFC applications.

This work proposes an alternate solution for two environmental challenges: COVID-19 face masks and coastal sargassum waste. Co-pyrolysis is used to convert both wastes into valuable biochar. Ground face masks and Sargassum spp. biomass were mixed in weight ratios of 1:2 and 1:3. Pyrolysis results indicated that high biomass ratios had a positive effect on biochar production. Activation and co-pyrolysis were performed using CUB-SP, KOH, and water, followed by hydrothermal treatment with N 2 H 4. Physicochemical characterization of metal-free electrocatalysts was conducted using various techniques. The COC-ADO catalyst displayed promising performance, with an onset potential of 0.85 V, a half-wave potential of 0.65 V for ORR, and a current density of 1.96 mA cm−2 at 0.2 V vs RHE, equivalent to 35% of the Pt–C electrocatalyst yield. These findings contribute to understanding the appropriate levels of face masks in sargassum waste management for the production of biochar suitable for AEMFC applications. [Display omitted] • The co-pyrolysis of face masks and biomass is a viable option for obtaining biochar. • The doped biochar has a promising potential for energy conversion. • It was developed a promising, sustainable and efficient electrocatalyst for the ORR. • Chemical surface composition shows nitrogen species in these electrocatalysts. [ABSTRACT FROM AUTHOR]