Graphene-based aerogels derived from biomass for energy storage and environmental remediation

Abstract

To resist the energy crisis and increasingly environmental pollution, there is a great demand for the development of sustainable materials for use in high-performance energy storage devices and environmental applications. However, it is a great challenge to realize both ultrahigh power density and high energy density in symmetric supercapacitors (SCs) by using materials synthesized from bioresources. Herein, we report the synthesis of hierarchical and lightweight graphene aerogels (GAs) with interconnected three-dimensional (3D) nanostructures for the fabrication of high performance coin cell-type SCs. GAs synthesized from pear exhibited high surface area (1001 m² g⁻¹) and pore volume (0.68 cm³ g⁻¹), which tremendously increase its surface area up to 2323 m² g⁻¹ and pore volume of 1.15 cm³ g⁻¹ after chemical activation. SCs based on activated GAs delivered both high energy density of 56.80 Wh kg⁻¹ and high power density of 620.26 kW kg⁻¹. The capacitance retention was ∼83% after 10 000 successive cycles of charge/discharge, indicating good cyclability. Moreover, GAs showed great potential as excellent adsorbents for the removal of diverse dyes from wastewater. This approach allows us to take the full advantage of raw materials from nature for promising applications in sustainable energy as high-performance SCs and practical environmental remediation.