Darstellung und Modifikation von Synthetischem Graphen aus Biomolekül-basierten Kohlenstoffnanopunkten
Elektronische Halbleiter, Bauelemente und Schaltungen, Integrierte Systeme, Sensorik, Theoretische Elektrotechnik
Herstellung und Eigenschaften von Funktionsmaterialien
Zusammenfassung der Projektergebnisse
In this project, I laid a solid foundation for future research on the use of bio-molecule based CNDs in electronics and charge-storage applications. 3D-graphene and 3D-carbon networks were obtained by laser-assisted conversion of citric acid/urea-based CNDs and was used as binderfree electrodes in supercapacitors with promising electrochemical behavior. Through systematic optimization by, for example exclusion of O2 from the reaction atmosphere, electrodes with enhanced frequency response applicable for AC-line filtering were obtained. The low RC time constants in CND-based 3D-carbon distinguished from other carbon materials and paved the way for an unexpected application of CND-based electrodes. Experiments in which CNDs were used as additives in a precursor mixture for laser-reduced graphene oxide supported these findings. The electrochemical performance of thus obtained 3D-graphene-based supercapacitors was significantly improved in terms of capacitance and frequency response. Moreover, we demonstrated that the small size of CNDs allows for the homogeneous mixture with other nanomaterials, such as small-size Fe2O3 nanoparticles and the subsequent one-step conversion into functional composite materials. This enables the fabrication of highly conductive, uniformly distributed composite materials for a range of applications in, for example, electronics or catalysis. Another interesting application of CND-based 3D-carbon are memristive devices. Memristive effects have been observed for a range of materials, but up to date, carbon or graphitic materials have not been used for resistive switching due to a lack of control over the resistivity across the material. With our method, we found a way to tune the resistivity of 3D-carbon, and thereby, made switching in carbon nanostructures possible for the first time. Finally, new reactions of citric acid with amine-containing precursors were identified, leading to promising routes to new CNDs. The laser-assisted conversion of CNDs into 3D-graphene showcased the feasibility to use CNDs as starting materials for 2D graphene films. Fist promising results were obtained. With the herein described projects I opened the door for in-depth research on the use of CNDs as precursors for functional electronic materials.
Projektbezogene Publikationen (Auswahl)
- “A Simple Route to Porous Graphene from Carbon Nanodots for Supercapacitor Applications” Adv. Mater. 2018, 30, 1704449
Strauss, V.; Marsh, K.; Kowal, M. D.; El-Kady, M. F.; Kaner, R. B.
(Siehe online unter https://doi.org/10.1002/adma.201704449) - „Simple Route to Porous Graphene from Carbon Nanodots for Supercapacitor Applications” 16/033,266, 2018
Strauss, V.; El-Kady, M. F.; Kaner, R. B.
