Browsing by Author "Rümmeli, Mark H."
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- ItemAdvances and Trends in Chemically Doped Graphene(Weinheim : Wiley-VCH, 2020) Ullah, Sami; Shi, Qitao; Zhou, Junhua; Yang, Xiaoqin; Ta, Huy Q.; Hasan, Maria; Ahmad, Nasir Mahmood; Fu, Lei; Bachmatiuk, Alicja; Rümmeli, Mark H.Chemically doped graphene materials are fascinating because these have different desirable attributes with possible synergy. The inert and gapless nature of graphene can be changed by adding a small number of heteroatoms to substitute carbon in the lattice. The doped material may display superior catalytic activities; durable, fast, and selective sensing; improved magnetic moments; photoresponses; and activity in chemical reactions. In the current review, recent advances are covered in chemically doped graphene. First, the different types of heteroatoms, their bonding configurations, and briefly their properties are discussed. This is followed by the description of various synthesis and analytical methods essential for assessing the characteristics of heterographene with specific focus on the selected graphene materials of different dopants (particularly, single dopants, including N, B, S, P, first three halogens, Ge, and Ga, and codopants, such as N/O), and more importantly, up-to-date applications enabled by the intentional doping. Finally, outlook and perspectives section review the existing challenges, future opportunities, and possible ways to improve the graphitic materials. The goal is to update and inspire the readers to establish novel doped graphene with valuable properties and for current and futuristic applications. © 2020 The Authors. Published by Wiley-VCH GmbH
- ItemApplications of Carbon Nanotubes in the Internet of Things Era(Berlin ; Heidelberg [u.a.] : Springer, 2021) Pang, Jinbo; Bachmatiuk, Alicja; Yang, Feng; Liu, Hong; Zhou, Weijia; Rümmeli, Mark H.; Cuniberti, GianaurelioThe post-Moore's era has boosted the progress in carbon nanotube-based transistors. Indeed, the 5G communication and cloud computing stimulate the research in applications of carbon nanotubes in electronic devices. In this perspective, we deliver the readers with the latest trends in carbon nanotube research, including high-frequency transistors, biomedical sensors and actuators, brain-machine interfaces, and flexible logic devices and energy storages. Future opportunities are given for calling on scientists and engineers into the emerging topics.
- ItemApplications of MXenes in human-like sensors and actuators(New York, NY [u.a.] : Springer, 2022) Pang, Jinbo; Peng, Songang; Hou, Chongyang; Wang, Xiao; Wang, Ting; Cao, Yu; Zhou, Weijia; Sun, Ding; Wang, Kai; Rümmeli, Mark H.; Cuniberti, Gianaurelio; Liu, HongHuman beings perceive the world through the senses of sight, hearing, smell, taste, touch, space, and balance. The first five senses are prerequisites for people to live. The sensing organs upload information to the nervous systems, including the brain, for interpreting the surrounding environment. Then, the brain sends commands to muscles reflexively to react to stimuli, including light, gas, chemicals, sound, and pressure. MXene, as an emerging two-dimensional material, has been intensively adopted in the applications of various sensors and actuators. In this review, we update the sensors to mimic five primary senses and actuators for stimulating muscles, which employ MXene-based film, membrane, and composite with other functional materials. First, a brief introduction is delivered for the structure, properties, and synthesis methods of MXenes. Then, we feed the readers the recent reports on the MXene-derived image sensors as artificial retinas, gas sensors, chemical biosensors, acoustic devices, and tactile sensors for electronic skin. Besides, the actuators of MXene-based composite are introduced. Eventually, future opportunities are given to MXene research based on the requirements of artificial intelligence and humanoid robot, which may induce prospects in accompanying healthcare and biomedical engineering applications. [Figure not available: see fulltext.]
- ItemApplications of nanogenerators for biomedical engineering and healthcare systems(Weinheim : Wiley, 2021) Wang, Wanli; Pang, Jinbo; Su, Jie; Li, Fujiang; Li, Qiang; Wang, Xiaoxiong; Wang, Jingang; Ibarlucea, Bergoi; Liu, Xiaoyan; Li, Yufen; Zhou, Weijia; Wang, Kai; Han, Qingfang; Liu, Lei; Zang, Ruohan; Rümmeli, Mark H.; Li, Yang; Liu, Hong; Hu, Han; Cuniberti, GianaurelioThe dream of human beings for long living has stimulated the rapid development of biomedical and healthcare equipment. However, conventional biomedical and healthcare devices have shortcomings such as short service life, large equipment size, and high potential safety hazards. Indeed, the power supply for conventional implantable device remains predominantly batteries. The emerging nanogenerators, which harvest micro/nanomechanical energy and thermal energy from human beings and convert into electrical energy, provide an ideal solution for self‐powering of biomedical devices. The combination of nanogenerators and biomedicine has been accelerating the development of self‐powered biomedical equipment. This article first introduces the operating principle of nanogenerators and then reviews the progress of nanogenerators in biomedical applications, including power supply, smart sensing, and effective treatment. Besides, the microbial disinfection and biodegradation performances of nanogenerators have been updated. Next, the protection devices have been discussed such as face mask with air filtering function together with real‐time monitoring of human health from the respiration and heat emission. Besides, the nanogenerator devices have been categorized by the types of mechanical energy from human beings, such as the body movement, tissue and organ activities, energy from chemical reactions, and gravitational potential energy. Eventually, the challenges and future opportunities in the applications of nanogenerators are delivered in the conclusive remarks. The combination of nanogenerator and biomedicine have been accelerating the development of self‐powered biomedical devices, which show a bright future in biomedicine and healthcare such as smart sensing, and therapy.
- ItemBoosting flexible electronics with integration of two-dimensional materials(Weinheim : Wiley, 2024) Hou, Chongyang; Zhang, Shuye; Liu, Rui; Gemming, Thomas; Bachmatiuk, Alicja; Zhao, Hongbin; Jia, Hao; Huang, Shirong; Zhou, Weijia; Xu, Jian‐Bin; Pang, Jinbo; Rümmeli, Mark H.; Bi, Jinshun; Liu, Hong; Cuniberti, GianaurelioFlexible electronics has emerged as a continuously growing field of study. Two-dimensional (2D) materials often act as conductors and electrodes in electronic devices, holding significant promise in the design of high-performance, flexible electronics. Numerous studies have focused on harnessing the potential of these materials for the development of such devices. However, to date, the incorporation of 2D materials in flexible electronics has rarely been summarized or reviewed. Consequently, there is an urgent need to develop comprehensive reviews for rapid updates on this evolving landscape. This review covers progress in complex material architectures based on 2D materials, including interfaces, heterostructures, and 2D/polymer composites. Additionally, it explores flexible and wearable energy storage and conversion, display and touch technologies, and biomedical applications, together with integrated design solutions. Although the pursuit of high-performance and high-sensitivity instruments remains a primary objective, the integrated design of flexible electronics with 2D materials also warrants consideration. By combining multiple functionalities into a singular device, augmented by machine learning and algorithms, we can potentially surpass the performance of existing wearable technologies. Finally, we briefly discuss the future trajectory of this burgeoning field. This review discusses the recent advancements in flexible sensors made from 2D materials and their applications in integrated architecture and device design.
- ItemControllable sliding transfer of wafer‐size graphene(Hoboken, NJ : Wiley, 2016) Lu, Wenjing; Zeng, Mengqi; Li, Xuesong; Wang, Jiao; Tan, Lifang; Shao, Miaomiao; Han, Jiangli; Wang, Sheng; Yue, Shuanglin; Zhang, Tao; Hu, Xuebo; Mendes, Rafael G.; Rümmeli, Mark H.; Peng, Lianmao; Liu, Zhongfan; Fu, LeiThe innovative design of sliding transfer based on a liquid substrate can succinctly transfer high‐quality, wafer‐size, and contamination‐free graphene within a few seconds. Moreover, it can be extended to transfer other 2D materials. The efficient sliding transfer approach can obtain high‐quality and large‐area graphene for fundamental research and industrial applications.
- ItemCrystal structure, synthesis and characterization of different chromium-based two-dimensional compounds(Riyadh : Saudi Chemical Soc., 2023) Hasan, Maria; Ta, Huy Q.; Ullah, Sami; Yang, Xiaoqin; Luo, Jingping; Bachmatiuk, Alicja; Gemming, Thomas; Trzebicka, Barbara; Mahmood, Azhar; Zeng, Mengqi; Fu, Lei; Liu, Lijun; Rümmeli, Mark H.The field of two dimensional (2D) materials experienced a surge of discoveries after the isolation of graphene. Among these, the transition metal compounds of Molybdenum and tungsten have been the most extensively studied materials after graphene. More recently, their group member chromium has only recently come to the limelight after the discovery of its exciting magnetic properties. As such the body of work surrounding 2D chromium-based materials is growing. Here, we present an up-to-date summary of the chromium 2D materials showing the latest advances in their experimental synthesis, characterization and the applications of 2D Chromium-based compounds. Finally, we conclude with a perspective on the future of 2D chromium-based materials. We believe that this study will be helpful to understand the field of chromium-based 2D compounds.
- ItemFacile production of ultra-fine silicon nanoparticles(London : Royal Society Publishing, 2020) Tokarska, Klaudia; Shi, Qitao; Otulakowski, Lukasz; Wrobel, Pawel; Ta, Huy Quang; Kurtyka, Przemyslaw; Kordyka, Aleksandra; Siwy, Mariola; Vasylieva, Margaryta; Forys, Aleksander; Trzebick, Barbara; Bachmatiuk, Alicja; Rümmeli, Mark H.A facile procedure for the synthesis of ultra-fine silicon nanoparticles without the need for a Schlenk vacuum line is presented. The process consists of the production of a (HSiO1.5)n sol–gel precursor based on the polycondensation of low-cost trichlorosilane (HSiCl3), followed by its annealing and etching. The obtained materials were thoroughly characterized after each preparation step by electron microscopy, Fourier transform and Raman spectroscopy, X-ray dispersion spectroscopy, diffraction methods and photoluminescence spectroscopy. The data confirm the formation of ultra-fine silicon nanoparticles with controllable average diameters between 1 and 5 nm depending on the etching time.
- ItemFlexible Piezoresistive Polystyrene Composite Sensors Filled with Hollow 3D Graphitic Shells(Basel : MDPI, 2023) Guzenko, Nataliia; Godzierz, Marcin; Kurtyka, Klaudia; Hercog, Anna; Nocoń-Szmajda, Klaudia; Gawron, Anna; Szeluga, Urszula; Trzebicka, Barbara; Yang, Ruizhi; Rümmeli, Mark H.The objective of this research was to develop highly effective conductive polymer composite (CPC) materials for flexible piezoresistive sensors, utilizing hollow three-dimensional graphitic shells as a highly conductive particulate component. Polystyrene (PS), a cost-effective and robust polymer widely used in various applications such as household appliances, electronics, automotive parts, packaging, and thermal insulation materials, was chosen as the polymer matrix. The hollow spherical three-dimensional graphitic shells (GS) were synthesized through chemical vapor deposition (CVD) with magnesium oxide (MgO) nanoparticles serving as a support, which was removed post-synthesis and employed as the conductive filler. Commercial multi-walled carbon nanotubes (CNTs) were used as a reference one-dimensional graphene material. The main focus of this study was to investigate the impact of the GS on the piezoresistive response of carbon/polymer composite thin films. The distribution and arrangement of GS and CNTs in the polymer matrix were analyzed using techniques such as X-ray diffraction and scanning electron microscopy, while the electrical, thermal, and mechanical properties of the composites were also evaluated. The results revealed that the PS composite films filled with GS exhibited a more pronounced piezoresistive response as compared to the CNT-based composites, despite their lower mechanical and thermal performance.
- ItemGeneral synthesis of 2D rare-earth oxide single crystals with tailorable facets(Oxford : Oxford University Press, 2021) Li, Linyang; Lu, Fangyun; Xiong, Wenqi; Ding, Yu; Lu, Yangyi; Xiao, Yao; Tong, Xin; Wang, Yao; Jia, Shuangfeng; Wang, Jianbo; Mendes, Rafael G.; Rümmeli, Mark H.; Yuan, Shengjun; Zeng, Mengqi; Fu, LeiTwo-dimensional (2D) rare-earth oxides (REOs) are a large family of materials with various intriguing applications and precise facet control is essential for investigating new properties in the 2D limit. However, a bottleneck remains with regard to obtaining their 2D single crystals with specific facets because of the intrinsic non-layered structure and disparate thermodynamic stability of different facets. Herein, for the first time, we achieve the synthesis of a wide variety of high-quality 2D REO single crystals with tailorable facets via designing a hard-soft-acid-base couple for controlling the 2D nucleation of the predetermined facets and adjusting the growth mode and direction of crystals. Also, the facet-related magnetic properties of 2D REO single crystals were revealed. Our approach provides a foundation for further exploring other facet-dependent properties and various applications of 2D REO, as well as inspiration for the precise growth of other non-layered 2D materials.
- ItemGraphene-Like ZnO: A Mini Review(Basel : MDPI, 2016) Ta, Huy Q.; Zhao, Liang; Pohl, Darius; Pang, Jinbo; Trzebicka, Barbara; Rellinghaus, Bernd; Pribat, Didier; Gemming, Thomas; Liu, Zhongfan; Bachmatiuk, Alicja; Rümmeli, Mark H.The isolation of a single layer of graphite, known today as graphene, not only demonstrated amazing new properties but also paved the way for a new class of materials often referred to as two-dimensional (2D) materials. Beyond graphene, other 2D materials include h-BN, transition metal dichalcogenides (TMDs), silicene, and germanene, to name a few. All tend to have exciting physical and chemical properties which appear due to dimensionality effects and modulation of their band structure. A more recent member of the 2D family is graphene-like zinc oxide (g-ZnO) which also holds great promise as a future functional material. This review examines current progress in the synthesis and characterization of g-ZnO. In addition, an overview of works dealing with the properties of g-ZnO both in its pristine form and modified forms (e.g., nano-ribbon, doped material, etc.) is presented. Finally, discussions/studies on the potential applications of g-ZnO are reviewed and discussed.
- ItemGrowth of all-carbon horizontally aligned single-walled carbon nanotubes nucleated from fullerene-based structures(London : BioMed Central, 2013) Ibrahim, Imad; Zhang, Yang; Popov, Alexey; Dunsch, Lothar; Büchner, Bernd; Cuniberti, Gianaurelio; Rümmeli, Mark H.All-carbon single-walled carbon nanotubes (SWCNTs) were successfully synthesized, nucleated using a fullerene derivative. A systematic investigation into the initial preparation of C60 fullerenes as growth nucleators for the SWCNTs was conducted. Enhancement in the yield of the produced SWCNT has been achieved with exploring different dispersing media for the fullerenes, the period, and environment of the initial thermal treatment of the fullerenes in addition to the use of different fullerene-based structures. The systematic studies significantly advance our understanding of the growth of the all-carbon catalyst-free single-walled carbon nanotubes. Field-effect transistors were fabricated using the catalyst-free SWCNT and then electrically characterized, showing current capacity as high as the well-studied catalyst-assisted nanotubes.
- ItemHigh-performance electronics and optoelectronics of monolayer tungsten diselenide full film from pre-seeding strategy(Weinheim : Wiley, 2021) Zhang, Shu; Pang, Jinbo; Cheng, Qilin; Yang, Feng; Chen, Yu; Liu, Yu; Li, Yufen; Gemming, Thomas; Liu, Xiaoyan; Ibarlucea, Bergoi; Yang, Jiali; Liu, Hong; Zhou, Weijia; Cuniberti, Gianaurelio; Rümmeli, Mark H.Tungsten diselenide (WSe2) possesses extraordinary electronic properties for applications in electronics, optoelectronics, and emerging exciton physics. The synthesis of monolayer WSe2 film is of topmost for device arrays and integrated circuits. The monolayer WSe2 film has yet been reported by thermal chemical vapor deposition (CVD) approach, and the nucleation mechanism remains unclear. Here, we report a pre-seeding strategy for finely regulating the nuclei density at an early stage and achieving a fully covered film after chemical vapor deposition growth. The underlying mechanism is heterogeneous nucleation from the pre-seeding tungsten oxide nanoparticles. At first, we optimized the precursor concentration for pre-seeding. Besides, we confirmed the superiority of the pre-seeding method, compared with three types of substrate pretreatments, including nontreatment, sonication in an organic solvent, and oxygen plasma. Eventually, the high-quality synthetic WSe2 monolayer film exhibits excellent device performance in field-effect transistors and photodetectors. We extracted thermodynamic activation energy from the nucleation and growth data. Our results may shed light on the wafer-scale production of homogeneous monolayer films of WSe2, other 2D materials, and their van der Waals heterostructures.
- ItemIn Situ Fabrication of Freestanding Single-Atom-Thick 2D Metal/Metallene and 2D Metal/ Metallene Oxide Membranes: Recent Developments(Weinheim : Wiley-VCH, 2021) Ta, Huy Q.; Mendes, Rafael G.; Liu, Yu; Yang, Xiaoqin; Luo, Jingping; Bachmatiuk, Alicja; Gemming, Thomas; Zeng, Mengqi; Fu, Lei; Liu, Lijun; Rümmeli, Mark H.In recent years, two-dimensional (2D) materials have attracted a lot of research interest as they exhibit several fascinating properties. However, outside of 2D materials derived from van der Waals layered bulk materials only a few other such materials are realized, and it remains difficult to confirm their 2D freestanding structure. Despite that, many metals are predicted to exist as 2D systems. In this review, the authors summarize the recent progress made in the synthesis and characterization of these 2D metals, so called metallenes, and their oxide forms, metallene oxides as free standing 2D structures formed in situ through the use of transmission electron microscopy (TEM) and scanning TEM (STEM) to synthesize these materials. Two primary approaches for forming freestanding monoatomic metallic membranes are identified. In the first, graphene pores as a means to suspend the metallene or metallene oxide and in the second, electron-beam sputtering for the selective etching of metal alloys or thick complex initial materials is employed to obtain freestanding single-atom-thick 2D metal. The data show a growing number of 2D metals/metallenes and 2D metal/ metallene oxides having been confirmed and point to a bright future for further discoveries of these 2D materials.
- ItemLarge-Area Single-Crystal Graphene via Self-Organization at the Macroscale(Weinheim : Wiley-VCH, 2020) Ta, Huy Quang; Bachmatiuk, Alicja; Mendes, Rafael Gregorio; Perello, David J.; Zhao, Liang; Trzebicka, Barbara; Gemming, Thomas; Rotkin, Slava V.; Rümmeli, Mark H.In 1665 Christiaan Huygens first noticed how two pendulums, regardless of their initial state, would synchronize. It is now known that the universe is full of complex self-organizing systems, from neural networks to correlated materials. Here, graphene flakes, nucleated over a polycrystalline graphene film, synchronize during growth so as to ultimately yield a common crystal orientation at the macroscale. Strain and diffusion gradients are argued as the probable causes for the long-range cross-talk between flakes and the formation of a single-grain graphene layer. The work demonstrates that graphene synthesis can be advanced to control the nucleated crystal shape, registry, and relative alignment between graphene crystals for large area, that is, a single-crystal bilayer, and (AB-stacked) few-layer graphene can been grown at the wafer scale. © 2020 The Authors. Published by Wiley-VCH GmbH
- ItemMonitoring microbial metabolites using an inductively coupled resonance circuit(London : Nature Publishing Group, 2015) Karnaushenko, Daniil; Baraban, Larysa; Ye, Dan; Uguz, Ilke; Mendes, Rafael G.; Rümmeli, Mark H.; de Visser, J. Arjan G.M.; Schmidt, Oliver G.; Cuniberti, Gianaurelio; Makarov, DenysWe present a new approach to monitor microbial population dynamics in emulsion droplets via changes in metabolite composition, using an inductively coupled LC resonance circuit. The signal measured by such resonance detector provides information on the magnetic field interaction with the bacterial culture, which is complementary to the information accessible by other detection means, based on electric field interaction, i.e. capacitive or resistive, as well as optical techniques. Several charge-related factors, including pH and ammonia concentrations, were identified as possible contributors to the characteristic of resonance detector profile. The setup enables probing the ionic byproducts of microbial metabolic activity at later stages of cell growth, where conventional optical detection methods have no discriminating power.
- ItemThe polycyclic aromatic hydrocarbon concentrations in soils in the Region of Valasske Mezirici, the Czech Republic(London : BioMed Central, 2009) Plachá, Daniela; Raclavská, Helena; Rümmeli, Mark H.The polycyclic aromatic hydrocarbon (PAH) contamination of urban, agricultural and forest soil samples was investigated from samples obtained in the surroundings of Valasske Mezirici. Valasske Mezirici is a town located in the north-east mountainous part of the Czech Republic, where a coal tar refinery is situated. 16 PAHs listed in the US EPA were investigated. Organic oxidizable carbon was also observed in the forest soils. The PAH concentrations ranged from 0.86-10.84 (with one anomalous value of 35.14) and 7.66-79.39 mg/kg dm in the urban/agricultural and forest soils, respectively. While the PAH levels in the urban/agricultural soils are within the range typically found in industrialized areas, the forest soils showed elevated PAH concentrations compared to other forest soils in Western and Northern Europe. The PAH concentrations and their molecular distribution ratios were studied as functions of the sample location and the meteorological history. The soils from localities at higher altitudes above sea level have the highest PAH concentrations, and the PAH concentrations decrease with increasing distance from the town.
- ItemRegulation of Two-Dimensional Lattice Deformation Recovery(Amsterdam [u.a.] : Elsevier, 2019) Liu, Jinxin; Zhou, Lu; Huang, Ke; Song, Xianyin; Chen, Yunxu; Liang, Xiaoyang; Gao, Jin; Xiao, Xiangheng; Rümmeli, Mark H.; Fu, LeiThe lattice directly determines the electronic structure, and it enables controllably tailoring the properties by deforming the lattices of two-dimensional (2D)materials. Owing to the unbalanced electrostatic equilibrium among the dislocated atoms, the deformed lattice is thermodynamically unstable and would recover to the initial state. Here, we demonstrate that the recovery of deformed 2D lattices could be directly regulated via doping metal donors to reconstruct electrostatic equilibrium. Compared with the methods that employed external force fields with intrinsic instability and nonuniformity, the stretched 2D molybdenum diselenide (MoSe2)could be uniformly retained and permanently preserved via doping metal atoms with more outermost electrons and smaller electronegativity than Mo. We believe that the proposed strategy could open up a new avenue in directly regulating the atomic-thickness lattice and promote its practical applications based on 2D crystals. © 2019 The Author(s)
- ItemSilicon carbide-free graphene growth on silicon for lithium-ion battery with high volumetric energy density(London : Nature Publishing Group, 2015) Son, In Hyuk; Park, Jong Hwan; Kwon, Soonchul; Park, Seongyong; Rümmeli, Mark H.; Bachmatiuk, Alicja; Song, Hyun Jae; Ku, Junhwan; Choi, Jang Wook; Choi, Jae-man; Doo, Seok-Gwang; Chang, HyukSilicon is receiving discernable attention as an active material for next generation lithium-ion battery anodes because of its unparalleled gravimetric capacity. However, the large volume change of silicon over charge–discharge cycles weakens its competitiveness in the volumetric energy density and cycle life. Here we report direct graphene growth over silicon nanoparticles without silicon carbide formation. The graphene layers anchored onto the silicon surface accommodate the volume expansion of silicon via a sliding process between adjacent graphene layers. When paired with a commercial lithium cobalt oxide cathode, the silicon carbide-free graphene coating allows the full cell to reach volumetric energy densities of 972 and 700 Wh l−1 at first and 200th cycle, respectively, 1.8 and 1.5 times higher than those of current commercial lithium-ion batteries. This observation suggests that two-dimensional layered structure of graphene and its silicon carbide-free integration with silicon can serve as a prototype in advancing silicon anodes to commercially viable technology.
- ItemSingle-atom catalytic growth of crystals using graphene as a case study(London : Nature Publishing Group, 2021) Yang, Xiaoqin; Liu, Yu; Ta, Huy Q.; Rezvani, Ehsan; Zhang, Yue; Zeng, Mengqi; Fu, Lei; Bachmatiuk, Alicja; Luo, Jinping; Liu, Lijun; Rümmeli, Mark H.Anchored Single-atom catalysts have emerged as a cutting-edge research field holding tremendous appeal for applications in the fields of chemicals, energy and the environment. However, single-atom-catalysts for crystal growth is a nascent field. Of the few studies available, all of them are based on state-of-the-art in situ microscopy investigations and computational studies, and they all look at the growth of monolayer graphene from a single-atom catalyst. Despite the limited number of studies, they do, collectively, represent a new sub-field of single-atom catalysis, namely single-atom catalytic growth of crystalline solids. In this review, we examine them on substrate-supported and as freestanding graphene fabrication, as well as rolled-up graphene, viz., single-walled carbon nanotubes (SWCNT), grown from a single atom. We also briefly discuss the catalytic etching of graphene and SWCNT’s and conclude by outlining the future directions we envision this nascent field to take.