Direct upcycling of highly efficient sorbents for emerging organic contaminants into high energy content supercapacitors
Veronika Šedajová, Debabrata Nandi, Petr Langer, Rabindranath Lo, Pavel Hobza, Daniela Plachá, Aristides Bakandritsos, Radek Zbořil
Abstract
After efficiently removing pharmaceuticals from water, spent sorbents made from tailored graphene derivatives are directly repurposed into highly competitive and redox-active supercapacitor electrodes. • Supercapacitor made from spent graphene sorbents outperform pristine graphene electrodes and state of the art materials. • Hgh performance and stability are due to the redox-active strongly adsorbed pollutants on the conductive graphenes. • Upcycling spent sorbents avoids environmental and economic burden, fostering sustainable energy and resource management. The escalation of anthropogenic activities contributes to the accumulation of chemicals in life-supporting ecosystems and water reserves, while nearly 80% of the global population faces a high risk of water insecurity. Therefore, advanced nanomaterials for environmental remediation and ecosystem preservation are essential. However, their adoption has been slow, mainly due to the need for water treatment strategies that comply with sustainability criteria. This work showcases the efficient removal of emerging pharmaceutical pollutants from water using functionalized graphenes and the direct upcycling of the used sorbents into electrodes for energy storage, without the need for any intermediate treatment. Remarkably, the performance of the repurposed sorbents as supercapacitor electrodes exceeds that of the parent functionalized graphenes by up to 100% in a full cell device. This enhanced performance and cycling stability are attributed to improved charge transport and redox activity induced by the strong adsorption of the pollutants, as supported by theoretical calculations. The findings open avenues for reclaiming the value of spent sorbents, mitigating the environmental and economic burden of their disposal or regeneration, while fostering sustainable resource management, and energy storage.