Facile Synthesis of a Highly Value-Added High-Performance Carbon Material from Waste Masks for Advanced Supercapacitors

Abstract

The practical use of supercapacitors necessitates the development of efficient carbon electrodes. Currently, the recycling of discarded masks (polypropylene, PP) produced during the COVID-19 epidemic has become a social problem that has attracted widespread attention. Converting these waste materials into high-performance electrode materials offers a sustainable and cost-effective solution, paving the way for resource-efficient energy storage technologies. Herein, through a simple sulfonation cross-linking strategy to improve the thermal stability of polypropylene (PP) molecular chains and followed NaOH activation, we successfully transformed the discarded masks into a highly value-added activated carbon material (SMAC). The process of sulfonation introduces oxgen-containing functional groups, which serves to improve both the wetting properties of the interface between the electrode and electrolyte, as well as contributes to the increase in pseudocapacitance. Therefore, the optimal SMAC-2 with a large specific surface area of 2629.7 m2 g–1 demonstrated an adequate specific capacitance of 338.1 F g–1 in 6 M KOH electrolyte, while maintaining a capacitance of 203.7 F g–1 even at a current density of 50 A g–1. In an organic electrolyte (1 M Et4NBF4/AN) with an expanded voltage window of 0–2.7 V, the SMAC-2 electrode delivered a specific capacitance of 138.1 F g–1 at 0.5 A g–1. Furthermore, the sodium-ion hybrid capacitor assembled with SMAC-2 and commercial hard carbon as the cathode and anode, respectively, reached an energy density of 117.3 Wh kg–1 at a power density of 257.3 W kg–1, highlighting the promising application prospects of the mask-derived activated carbon.

Effects of Potassium-Based Activating Agents on the Biochar Derived from Coconut Tree Husk for Enhancing the Surface Area and Supercapacitor Performance

“…The carbonyl groups (OCO) have the peak position at the binding energy of 532.1 eV; the carboxylic groups (CO) have the peak at the binding energy of 533.2 eV; and the hydroxyl groups (COH) have the peak at the binding energy of 534.3 eV. The above results suggest that, at a high temperature, the KMnO 4 activator strongly oxidizes the carbon materials to boost the oxygen content and etch out the non-oxygen atoms. , It has been established that adding oxygen-functional groups to carbon materials makes them more hydrophilic, maximizing the use of their large specific surface areas and improving their capacity for energy storage …”

“…The above results suggest that, at a high temperature, the KMnO 4 activator strongly oxidizes the carbon materials to boost the oxygen content and etch out the non-oxygen atoms. 34,41 It has been established that adding oxygen-functional groups to carbon materials makes them more hydrophilic, maximizing the use of their large specific surface areas and improving their capacity for energy storage. 42 Electrochemical Performances of AC.…”

Screen-Printed Stretchable Supercapacitors Based on Tin Sulfide-Decorated Face-Mask-Derived Activated Carbon Electrodes with High Areal Energy Density

“…Plastic or biomass waste-derived activated carbons are considered attractive material for supercapacitor electrodes due to their superior electrical conductivity, high specific surface area (SSA), and widespread availability. , The widespread usage of plastic-based face masks during the COVID-19 outbreak has resulted in harmful plastic waste . The face masks are made from single-use polypropylene (PP) fabrics, which cannot be recycled, and the majority of them are incinerated or disposed of as regular plastic waste, which is neither environment-friendly nor sustainable. , Hence, upcycling these waste face masks into activated carbons is a promising approach for producing high-value-added carbon electrode materials for supercapacitor applications.…”