Speaker
Description
Graphite, a stable allotrope of carbon, boasts unique properties including high electrical conductivity, and excellent thermal and chemical stability. Currently, the demand for graphite in both research and development is rapidly increasing. Despite the abundance of high quality of natural graphite, synthetic graphite remains attractive due to scalable production, controlled property tuning, sustainability and suitability for emerging energy and electronic applications. Its synthesis typically involves thermal treatment of carbonaceous materials such as petroleum coke, coal tar pitch, or polymer-derived carbons. We present the synthesis of high-quality graphite on nickel foils using a carbon rich product derived from hydrothermal carbonization (HTC) of waste cigarettes filters. The HTC of cigarette filters yields CSs with functional properties in energy and are also well suited as precursors for subsequent graphitization. X-ray diffraction (XRD) shows a broad diffraction peak at 23° corresponding to the (002) plane, which is characteristic of largely amorphous carbons and turbostratic graphite packing. Scanning electron microscopy (SEM) reveals the spherical morphology of the products, with a mean diameter of 6.2 μm. The corresponding energy-dispersive X-ray spectroscopy (EDS) elemental maps of carbon and oxygen indicate that the CSs contains 74 wt.% carbon and 26 wt.% oxygen. Fourier Transform Infrared spectroscopy (FTIR) further reveal that oxygen species on the CSs exist as C–OH, COOH, and C=O functional groups bound to the carbon framework. The functional properties of these CSs will be tested in capacitors, batteries, and hydrovoltaics. Furthermore, the CSs will be converted into epitaxial graphite following an isothermal dissolution-diffusion-precipitation (IDDP) process using single crystal nickel foils. The graphite will be exfoliated into graphene, and the functional properties of the resulting graphene will be tested in twisted bilayer graphene superconductors, field-effect transistors, and sensors. The conversion of cigarette filters into energy- and electronic-grade synthetic functional carbon materials provides a scalable and sustainable route to high-performance materials while mitigating a major environmental pollutant.
| Keyword-1 | waste cigarette filter |
|---|---|
| Keyword-2 | carbon spheres |
| Keyword-3 | functional carbon materials |