Holey and Wrinkled Flash Graphene from Mixed Plastic Waste

Abstract

High surface area varieties of graphene have captured significant attention, allowing for improved performance in a variety of applications. However, there are challenges facing the use of graphene in these applications since it is expensive and difficult to synthesize in bulk. Here, we leverage the capabilities of flash Joule heating to synthesize holey and wrinkled flash graphene (HWFG) in seconds from mixed plastic waste feedstocks, using in situ salt decomposition to produce and stabilize pore formation during the reaction. Surface areas as high as 874 m2 g–1 are obtained, with characteristics of micro-, meso-, and macroporosities. Raman spectroscopy confirms the wrinkled and turbostratic nature of the HWFG. We demonstrate HWFG applications in its use as a metal-free hydrogen evolution reaction electrocatalyst, with excellent stability, competitive overpotential, and Tafel slope; in a Li-metal battery anode allowing for stable and high discharge rates; and in a material with high gas adsorption. This represents an upcycle of mixed plastic waste, thereby affording a valuable route to address this pressing environmental pollutant concern.

Growth of High-Purity and High-Quality Turbostratic Graphene with Different Interlayer Spacings

“…In the case of turbostratic graphene powder, Athanasiou et al showed the growth of turbostratic graphene powder using a laser-assisted process . The flash Joule heating process is a new method for synthesizing turbostratic graphene powder by compressing the carbon source to increase its temperature to higher than 3000 K in less than 100 ms. , However, the flash Joule heating system has a risk of electrical shock or electrocution. Hu et al demonstrated the growth of turbostratic graphene powder using concentrated solar radiation .…”

Plastic Waste Valorization by Leveraging Multidisciplinary Catalytic Technologies

“…A high-voltage electric discharge induces temperatures of the carbon source higher than 3000 K in less than 100 ms, effectively converting carbon feedstocks into turbostratic FG. They successfully leveraged this technology for upcycling of single or mixed plastics (PET, PE, PP, PS, polyvinyl chloride (PVC), polyacrylonitrile (PAN), polyurethane, plastic waste pyrolysis ash) to high-quality graphene. − For example, they recently reported the synthesis of a holey and wrinkled flash graphene (HWFG) in seconds from mixed plastic waste feedstocks . The HWFG was then found to be effective as a Li-metal battery anode, metal-free hydrogen evolution reaction (HER) electrocatalyst, and CO 2 gas adsorption material.…”

“…52−56 For example, they recently reported the synthesis of a holey and wrinkled flash graphene (HWFG) in seconds from mixed plastic waste feedstocks. 54 The HWFG was then found to be effective as a Li-metal battery anode, metal-free hydrogen evolution reaction (HER) electrocatalyst, and CO 2 gas adsorption material. Importantly, this technology is scalable for handling waste plastics, showing potential for reducing carbon emission, energy consumption, and water usage compared with the conventional synthetic method of graphene.…”

Waste-Derived Catalysts for Water Electrolysis: Circular Economy-Driven Sustainable Green Hydrogen Energy

“…More recently, Wyss and coworkers developed a Joule heating process to convert mixed plastic wastes into holey and wrinkled flash graphene (HWFG) (Fig. 5f) [103]. The obtained graphene contains rich three-dimensional (3D) and 2D pores and displays a large surface area (874 m 2 g -1 ).…”

“…Niu et al designed graphene sponges by employing SiO 2 spheres as the hard template and chitosan biomass as the carbon source [104]. With a spatial structure and high surface area, the obtained defective N-doped graphene sponge shows a good HER activity (η 0.5 = 203 mV) and excellent durability for about 2 h. For potential applications, the stability test [103]. Copyright 2022, American Chemical Society.…”