1. Introduction
Carbon-based nanomaterials have garnered widespread attention and application because of their exceptional electrical conductivity, thermal conductivity, mechanical strength, and optical properties. Common representative materials mainly include graphene, carbon nanotubes, fullerenes, and carbon quantum dots [1,2,3]. These materials not only attract significant interest because of their unique physical and chemical properties but also because they demonstrate immense potential in a wide range of fields. Therefore, exploring the key characteristics, application domains, and development prospects of carbon-based multifunctional nanomaterials is crucial for gaining a comprehensive understanding of this field and advancing its progress.
The exceptional properties of carbon-based multifunctional nanomaterials make them highly prominent in the fields of electronic devices and energy storage. Carbon materials can be classified into two-dimensional, one-dimensional, and zero-dimensional categories. For instance, two-dimensional graphene exhibits remarkable electrical and thermal conductivity, granting it significant potential in high-performance electronic devices, sensors, and supercapacitors. One-dimensional carbon nanotubes, with their unique structure, demonstrate outstanding mechanical strength and electrical conductivity, making them ideal for enhancing composite materials and fabricating nanoscale electronic devices [4]. Zero-dimensional materials such as fullerenes and carbon quantum dots, owing to their high specific surface area and excellent optical properties, excel in areas such as catalysis, optoelectronic devices, and bioimaging [5]. Moreover, carbon-based multifunctional nanomaterials show great promise in environmental protection and biomedical applications. For example, graphene can be employed for detecting pollutants in air and water. Carbon quantum dots, because of their excellent biocompatibility and strong fluorescence, are emerging as a research focus for the next generation of biomarkers and imaging probes [6]. Fullerenes and their derivatives also hold significant potential in drug delivery and antioxidant therapy.
Despite the remarkable performance advantages of carbon-based multifunctional nanomaterials in various fields, there are still some challenges in their practical application. First, the synthesis and functionalization processes of these nanomaterials need to be further optimized to reduce costs and improve consistency and reproducibility [7,8,9]. For example, structural defects and irregularities in the production of graphene and carbon nanotubes can affect the stability and reliability of their performance [10]. To address these challenges, researchers are exploring novel synthesis methods and functionalization techniques to meet the needs of various applications. Furthermore, the integration of nanomaterials with other functional materials could further improve their properties. In summary, carbon-based multifunctional nanomaterials, as a new generation of high-performance materials, are at the forefront of materials science research because of their exceptional physical and chemical properties and their broad application potential.
2. An Overview of Published Articles
Christoph et al. (Contribution 1) present a renewable source of carbon nanoparticles. They report the synthesis and material and biological characterization of two colloidal suspensions of CQDs in water derived from lignin-based carbon. The material exhibits non-toxic and biocompatible properties, laying a new foundation for the use of lignin-derived CQDs in tissue engineering applications.
Ioni et al. (Contribution 2) demonstrate a method for preparing a tailored composite based on nickel nanoparticles on the reduced graphene oxide surface using supercritical isopropanol treatment. The reduction in Ni salts enables the deoxygenation of graphene, with nickel nanoparticles uniformly distributed on the surface of graphene, and the composite exhibits magnetic properties. This enhances the understanding of the mechanism of composite fabrication in supercritical isopropanol.
Li et al. (Contribution 3) modified graphene with dopamine (PDA) at the interface, and then constructed multilayer composite films with boron nitride and bacterial cellulose. PDA improved the interface compatibility between the hybrid fillers and the matrix, increasing the material density and stabilizing the thermal conduction pathways. The composite film exhibited significant improvements in thermal conductivity and tensile strength.
Oswald et al. (Contribution 4) investigate the effects of thermally evaporated C60 (n-type) and Pentacene (p-type) thin films on the in-plane charge transport properties of large-area CVD graphene under vacuum. C60 induces a decrease in Fermi energy and an increase in Fermi energy in graphene. The increase in charge carriers was accompanied by a reduction in charge mobility. Interestingly, the contact resistance was not significantly affected by the deposition of the organic molecules.
Sun et al. (Contribution 5) provide a comprehensive overview of emerging materials and approaches in the development of smart thermally conductive fiber materials. Structural materials are classified based on their functions. Finally, they discuss the challenges and opportunities presented by smart thermally conductive fiber materials and present prospects for their future development.
3. Conclusions
Carbon-based multifunctional nanomaterials are expected to continue to play a pioneering role in materials science in the future and have great potential, particularly in the fields of electronics, energy storage, environmental protection, and biomedicine. Despite their enormous potential, current synthesis technologies face challenges such as high costs, difficulties in mass production, and performance instability, which require further technological breakthroughs. The future focus is on improving the manufacturing processes of carbon-based multifunctional nanomaterials to improve their quality, consistency, and controllability to meet the requirements of large-scale industrial production. Meanwhile, advances in functionalization techniques will provide these with materials improved competitiveness for certain applications. The performance of carbon-based multifunctional nanomaterials is also expected to be further improved through their integration with other functional materials, especially in the development of novel electronic devices, sensors, and efficient energy storage systems. In addition, with the increasing demand for environmentally friendly materials, the sustainability and environmental friendliness of carbon-based materials is also increasing.
Acknowledgments
The Guest Editors thank the authors for submitting their work to the Special Issue. A special thank you to all the reviewers and all the staff in the Editorial Office.
Conflicts of Interest
The authors declare no conflicts of interest.
List of Contributions
Christoph, E.; Yu, L.; Newby, S.D.; Rivera Orsini, M.A.; Scroggins, J.; Keffer, D.J.; Harper, D.P.; Dhar, M. Novel Kraft Softwood Lignin-Derived Carbon Quantum Dots: Synthesis, Characterization, and In Vitro Cytocompatibility. Nanomaterials 2024, 14, 1029. https://doi.org/10.3390/nano14121029
Ioni, Y.; Popova, A.; Maksimov, S.; Kozerozhets, I. Ni Nanoparticles on the Reduced Graphene Oxide Surface Synthesized in Supercritical Isopropanol. Nanomaterials 2023, 13, 2923. https://doi.org/10.3390/nano13222923
Li, S.; Shen, Y.; Jia, X.; Xu, M.; Zong, R.; Liu, G.; Liu, B.; Huai, X. Dopamine-Mediated Graphene Bridging Hexagonal Boron Nitride for Large-Scale Composite Films with Enhanced Thermal Conductivity and Electrical Insulation. Nanomaterials 2023, 13, 1210. https://doi.org/10.3390/nano13071210
Oswald, J.; Beretta, D.; Stiefel, M.; Furrer, R.; Vuillaume, D.; Calame, M. The Effect of C60 and Pentacene Adsorbates on the Electrical Properties of CVD Graphene on SiO2. Nanomaterials 2023, 13, 1134. https://doi.org/10.3390/nano13061134
Sun, Z.; Yu, H.; Feng, Y.; Feng, W. Application and Development of Smart Thermally Conductive Fiber Materials. Nanomaterials 2024, 14, 154. https://doi.org/10.3390/nano14020154
Funding Statement
Huitao Yu acknowledges the National Natural Science Foundation of China (Grant Nos. 52303101, 52327802), Young Elite Scientists Sponsorship Program by CAST (No. 2022QNRC001), Joint Funds of Ministry of Education (8091B032218), Tianjin University Independent Fund (2024XYY-0028), Tianjin University Science and Technology Leading Cultivation Program “Qiming Plan” (2023XQM-0048).
Footnotes
Disclaimer/Publisher’s Note: The statements, opinions and data contained in all publications are solely those of the individual author(s) and contributor(s) and not of MDPI and/or the editor(s). MDPI and/or the editor(s) disclaim responsibility for any injury to people or property resulting from any ideas, methods, instructions or products referred to in the content.
References
- 1.Yang W., Chen T., Xie L., Yu Y., Long M., Xu L. A systematic study of switching, optoelectronics, and gas-sensitive properties of PCF-graphene-based nanodevices: Insights from DFT study. Carbon Neutralization. 2024;3:904–917. doi: 10.1002/cnl2.156. [DOI] [Google Scholar]
- 2.Yu H., Feng Y., Chen C. Highly thermally conductive adhesion elastomer enhanced by vertically aligned folded graphene. Adv. Sci. 2022;9:2201331. doi: 10.1002/advs.202201331. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 3.Yang J., Shen X., Yang W., Kim J.K. Templating strategies for 3D-structured thermally conductive composites: Recent advances and thermal energy applications. Prog. Mater. Sci. 2023;133:101054. doi: 10.1016/j.pmatsci.2022.101054. [DOI] [Google Scholar]
- 4.Pan M., Xie X., Liu K., Yang J., Hong L., Wang S. Fluorescent Carbon Quantum Dots—Synthesis, Functionalization and Sensing Application in Food Analysis. Nanomaterials. 2020;10:930. doi: 10.3390/nano10050930. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 5.Yu H., Feng Y., Gao L., Chen C., Zhang Z., Feng W. Self-healing high strength and thermal conductivity of 3D graphene/PDMS composites by the optimization of multiple molecular interactions. Macromolecules. 2020;53:7161–7170. doi: 10.1021/acs.macromol.9b02544. [DOI] [Google Scholar]
- 6.Yu H., Peng L., Chen C., Qin M., Feng W. Regulatable Orthotropic 3D Hybrid Continuous Carbon Networks for Efficient Bi-Directional Thermal Conduction. Nano-Micro Lett. 2024;16:1–13. doi: 10.1007/s40820-024-01426-0. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 7.Jia Y., Jiang Y., Pan Y., Zou X., Zhang Q., Gao X., Zhang J., Yu K., Yang Y., Liu Y. Recent advances in energy storage and applications of form-stable phase change materials with recyclable skeleton. Carbon Neutralization. 2024;3:313–343. doi: 10.1002/cnl2.117. [DOI] [Google Scholar]
- 8.Li Z., Wang L., Li Y., Feng Y., Feng W. Carbon-based functional nanomaterials: Preparation, properties and applications. Compos. Sci. Technol. 2019;179:10–40. doi: 10.1016/j.compscitech.2019.04.028. [DOI] [Google Scholar]
- 9.Pan M., Yin Z., Liu K., Du X., Liu H., Wang S. Carbon-Based Nanomaterials in Sensors for Food Safety. Nanomaterials. 2019;9:1330. doi: 10.3390/nano9091330. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 10.Rabiee N., Bagherzadeh M., Ghadiri A.M., Kiani M., Fatahi Y., Tavakolizadeh M., Pourjavadi A., Jouyandeh M., Saeb M.R., Mozafari M. Multifunctional 3D hierarchical bioactive green carbon-based nanocomposites. ACS Sustain. Chem. Eng. 2021;9:8706–8720. doi: 10.1021/acssuschemeng.1c00781. [DOI] [Google Scholar]