Defects and defect-mediated engineering of two-dimensional materials: challenges and open questions

• Arkady V. Krasheninnikov,
• Matthias Batzill,
• Anouar-Akacha Delenda,
• Marija Drndić,
• Chris Ewels,
• Katharina J. Franke,
• Mahdi Ghorbani-Asl,
• Alexander Holleitner,
• Ado Jorio,
• Ute Kaiser,
• Daria Kieczka,
• Hannu-Pekka Komsa,
• Jani Kotakoski,
• Manuel Längle,
• David Lamprecht,
• Yun Liu,
• Steven G. Louie,
• Janina Maultzsch,
• Thomas Michely,
• Katherine Milton,
• Anna Niggas,
• Hanako Okuno,
• Joshua A. Robinson,
• Marika Schleberger,
• Bruno Schuler,
• Alexander Shluger,
• Kazu Suenaga,
• Kristian S. Thygesen,
• Richard A. Wilhelm,
• E. Harriet Åhlgren and
• Carla Bittencourt

Beilstein J. Nanotechnol. 2026, 17, 454–488, doi:10.3762/bjnano.17.31

• Abstract Compared to bulk solids, defects in low-dimensional materials and, specifically, 2D systems are expected to have a stronger effect, detrimental or beneficial, on their properties. Owing to their geometry, defects in 2D materials can easily be formed due to the interaction with the environment or

• under impacts of energetic particles, such as ions and electrons. At the same time, many concepts of defect production under irradiation in bulk systems are not applicable for 2D materials or require substantial modifications. Various aspects of the physics and chemistry of defects in 2D materials have

• -mediated engineering of nanomaterials for energy and quantum applications” organized by the Beilstein-Institut. Following the discussions at the symposium, here, we present the challenges and open questions in our understanding of the behavior of defective 2D materials, interaction of energetic particles

Advancing nanolithography: a comprehensive review of materials for local anodic oxidation with AFM

• Matteo Lorenzoni

Beilstein J. Nanotechnol. 2026, 17, 275–291, doi:10.3762/bjnano.17.19

• technique for nanoscale patterning, leveraging the precision of scanning probe microscopy, relying specifically on atomic force microscopy. This review explores the materials utilized in LAO experiments, including semiconductors, metals, insulators, two-dimensional (2D) materials, and emerging

• heterostructures. Semiconductors such as silicon and silicon carbide remain foundational due to their controllable oxidation kinetics, while metals like titanium and aluminum offer opportunities for plasmonic and optical applications. 2D materials, including graphene, graphene oxide, and transition metal

• aims to highlight the capability of LAO to pattern two-dimensional (2D) materials such as graphene [20][21][22], hexagonal boron nitride [23] (hBN), transition metal dichalcogenides (TMDs) [21][24][25][26][27], metals [18][28][29], as well as traditional semiconductors such as silicon (Si) [6][10][30

Time of flight secondary ion mass spectrometry imaging of contaminant species in chemical vapour deposited graphene on copper

• Barry Brennan,
• Vlad-Petru Veigang-Radulescu,
• Philipp Braeuninger-Weimer,
• Stephan Hofmann and
• Andrew J. Pollard

Beilstein J. Nanotechnol. 2026, 17, 200–213, doi:10.3762/bjnano.17.13

• & 2D Materials). SH, VV and PBW acknowledge funding from EPRSC (EP/K016636/1, EP/T001038/1).

Missing links in nanomaterials research impacting productivity and perceptions

• Santosh K. Tiwari and
• Nannan Wang

Beilstein J. Nanotechnol. 2025, 16, 2168–2176, doi:10.3762/bjnano.16.149

• , other 2D nanomaterials, such as elemental 2D materials (e.g., borophene, phosphorene, and silicene), transition metal dichalcogenides (e.g., MoS2, WS2, and NbSe2), transition metal oxides (e.g., MnO2, Fe2O3, and Ni(OH)2 nanosheets), MXenes (e.g., Ti3C2, Ti2C, and Ta4C3), 2D halides (e.g., CrI3, NiI2

Ambient pressure XPS at MAX IV

• Mattia Scardamaglia,
• Ulrike Küst,
• Alexander Klyushin,
• Rosemary Jones,
• Jan Knudsen,
• Robert Temperton,
• Andrey Shavorskiy and
• Esko Kokkonen

Beilstein J. Nanotechnol. 2025, 16, 1677–1694, doi:10.3762/bjnano.16.118

• representative studies at MAX IV, including investigations of single-atom catalysts, confined catalysis, time-resolved catalysis, atomic layer deposition, and electrochemical interfaces, showcasing the role of APXPS in advancing material and surface science. Keywords: 2D materials; atomic layer deposition

• and allows the CO to intercalate and then oxidize. Rather than studying the reaction below 2D materials, Scardamaglia et al. investigated graphene and hBN as protective layers for copper metal surfaces in a reactive environment [31]. In operando experiments with a linear temperature ramp in 2 mbar O2

• , bare copper rapidly oxidized to Cu2O at room temperature and further to CuO at ~200 °C. However, with hBN or graphene layers, oxidation was significantly delayed. Both 2D materials retard the oxidation of Cu by more than 120 °C, but with different kinetics. The behavior of hBN/Cu is relatively simple

Nanotechnology-based approaches for the removal of microplastics from wastewater: a comprehensive review

• Nayanathara O Sanjeev,
• Manjunath Singanodi Vallabha and
• Rebekah Rubidha Lisha Rabi

Beilstein J. Nanotechnol. 2025, 16, 1607–1632, doi:10.3762/bjnano.16.114

• area and layered, folded structures. These 2D materials are known for their chemical robustness, surface functionality, hydrophilicity, excellent electrical conductivity, and eco-friendly nature. Due to these properties, MXenes, particularly titanium carbide derivatives (Ti3C2Tx), have become widely

Transient electronics for sustainability: Emerging technologies and future directions

• Jae-Young Bae,
• Myung-Kyun Choi and
• Seung-Kyun Kang

Beilstein J. Nanotechnol. 2025, 16, 1545–1556, doi:10.3762/bjnano.16.109

• unfolds on the brain cortex to enable neural signal monitoring following syringe-based implantation [27] (Figure 1d). The exploration of new materials and fabrication techniques has also enabled the realization of large-area transient devices. In particular, the large-area fabrication of 2D materials and

Laser processing in liquids: insights into nanocolloid generation and thin film integration for energy, photonic, and sensing applications

• Akshana Parameswaran Sreekala,
• Pooja Raveendran Nair,
• Jithin Kundalam Kadavath,
• Bindu Krishnan,
• David Avellaneda Avellaneda,
• M. R. Anantharaman and
• Sadasivan Shaji

Beilstein J. Nanotechnol. 2025, 16, 1428–1498, doi:10.3762/bjnano.16.104

Thickness dependent oxidation in CrCl₃: a scanning X-ray photoemission and Kelvin probe microscopies study

• Shafaq Kazim,
• Rahul Parmar,
• Maryam Azizinia,
• Matteo Amati,
• Muhammad Rauf,
• Andrea Di Cicco,
• Seyed Javid Rezvani,
• Dario Mastrippolito,
• Luca Ottaviano,
• Tomasz Klimczuk,
• Luca Gregoratti and
• Roberto Gunnella

Beilstein J. Nanotechnol. 2025, 16, 749–761, doi:10.3762/bjnano.16.58

• ) provides an ideal spot size for the study of 2D materials, focusing on the character of the material in relation to its shape. Sample flakes in the range of 1–10 μm2, obtained by the exfoliation technique, can be analyzed by SPEM on such characteristic lengths by the precise control of the relative

Strain-induced bandgap engineering in 2D ψ-graphene materials: a first-principles study

• Kamal Kumar,
• Nora H. de Leeuw,
• Jost Adam and
• Abhishek Kumar Mishra

Beilstein J. Nanotechnol. 2024, 15, 1440–1452, doi:10.3762/bjnano.15.116

• Interdisciplinary Nanostructure Science and Technology, University of Kassel, Heinrich-Plett-Straße 40, 34132 Kassel, Germany 10.3762/bjnano.15.116 Abstract High mechanical strength, excellent thermal and electrical conductivity, and tunable properties make two-dimensional (2D) materials attractive for various

• . The mechanical strain tolerance of pristine and fully hydrogenated ψ-graphene is observed to be −17% to +17%, while for ψ-graphone, it lies within the strain span of −16% to +16%. Keywords: 2D materials; defects; DFT; graphene; ψ-graphene; strain; Introduction Graphene is the best-known zero-bandgap

• transition of graphene from a semimetal to an insulator after full hydrogenation [9]. After the discovery of graphene, other novel 2D materials, such as goldene [10], stanene [11], plumbene [12], antimonene [13], and arsenene [14], have been predicted and experimentally synthesized. Few of these materials

Out-of-plane polarization induces a picosecond photoresponse in rhombohedral stacked bilayer WSe₂

• Guixian Liu,
• Yufan Wang,
• Zhoujuan Xu,
• Zhouxiaosong Zeng,
• Lanyu Huang,
• Cuihuan Ge and
• Xiao Wang

Beilstein J. Nanotechnol. 2024, 15, 1362–1368, doi:10.3762/bjnano.15.109

• photoelectric detection. Experimental Device fabrication The 2D materials, WSe2 and graphene, were obtained from high-quality bulk crystals using the mechanical exfoliation method. The monolayer WSe2 nanoflakes were exfoliated onto a transparent polydimethylsiloxane (PDMS) film, selected based on optical

Interaction of graphene oxide with tannic acid: computational modeling and toxicity mitigation in C. elegans

• Romana Petry,
• James M. de Almeida,
• Francine Côa,
• Felipe Crasto de Lima,
• Diego Stéfani T. Martinez and
• Adalberto Fazzio

Beilstein J. Nanotechnol. 2024, 15, 1297–1311, doi:10.3762/bjnano.15.105

• Agency (EPA), herein named EPA medium, in absence and presence of TA. Atomic force microscopy AFM has been extensively used to characterize the distribution and morphology of biomolecules on the surface of nanomaterials, especially 2D materials [37]. Figure 1a and Figure 1b show AFM images of GO sheets

Quantum-to-classical modeling of monolayer Ge₂Se₂ and its application in photovoltaic devices

• Anup Shrivastava,
• Shivani Saini,
• Dolly Kumari,
• Sanjai Singh and
• Jost Adam

Beilstein J. Nanotechnol. 2024, 15, 1153–1169, doi:10.3762/bjnano.15.94

• optoelectronic devices, including next-generation solar cells. The hybrid quantum-to-macroscopic methodology presented here applies to broader classes of 2D and 3D materials and structures, showing a path to the computational design of future photovoltaic materials. Keywords: 2D materials; density functional

• -term instability, poor device scalability, and the use of toxic compounds, have yet to be resolved [6]. Recent advancements have seen the integration of two-dimensional (2D) materials with PSCs, opening new avenues for enhancing their performance and addressing current challenges with the PSCs [7][8

• ]. Integrating 2D materials in PSCs can improve their performance. The 2D materials can provide protective layers that work like a shield to the perovskite materials to protect them from environmental degradation caused by moisture and oxygen and provide better device scalability to the PSCs, which makes large

Exploring surface charge dynamics: implications for AFM height measurements in 2D materials

• Mario Navarro-Rodriguez,
• Andres M. Somoza and
• Elisa Palacios-Lidon

Beilstein J. Nanotechnol. 2024, 15, 767–780, doi:10.3762/bjnano.15.64

• monolayer flakes of 2D materials is the inaccurate height derived from topography images, often attributed to capillary or electrostatic forces. Here, we show the existence of a Joule dissipative mechanism related to charge dynamics and supplementing the dissipation due to capillary forces. This particular

• mechanism arises from the surface conductivity and assumes significance specially in the context of 2D materials on insulating supports. In such scenarios, the oscillating tip induces in-plane charge currents that in many circumstances constitute the main dissipative contribution to amplitude reduction and

• of surface charges and their intricate interaction with the tip. Keywords: 2D materials; incorrect height measurements; Joule dissipation; surface conductivity; tip influence; Introduction Two-dimensional (2D) materials have emerged as a promising platform for next-generation electronic devices [1

Level set simulation of focused ion beam sputtering of a multilayer substrate

• Alexander V. Rumyantsev,
• Nikolai I. Borgardt,
• Roman L. Volkov and
• Yuri A. Chaplygin

Beilstein J. Nanotechnol. 2024, 15, 733–742, doi:10.3762/bjnano.15.61

• multilayer films [8], the patterning of 2D materials [9], or the direct introduction of dopants into a solid-state host through recoil implantation [10]. Examples that rely on ion milling include patterning of magnetic multilayers [11], fabrication of optical metamaterials [12], and modification of

Exfoliation of titanium nitride using a non-thermal plasma process

• Priscila Jussiane Zambiazi,
• Dolores Ribeiro Ricci Lazar,
• Larissa Otubo,
• Rodrigo Fernando Brambilla de Souza,
• Almir Oliveira Neto and
• Cecilia Chaves Guedes-Silva

Beilstein J. Nanotechnol. 2024, 15, 631–637, doi:10.3762/bjnano.15.53

• -dimensional (2D) materials with exceptional physical and chemical properties. These materials are typically exfoliated from three-dimensional (3D) layered crystals characterized by atomically thin layers held together by strong in-plane covalent bonds and weak out-of-plane van der Waals (vdW) forces. Apart

• a distinct class of 2D materials. These novel materials consist of ultrathin nanosheets but are synthesized from non-van der Waals (n-vdW) bulk crystals featuring strong chemical bonds in all directions [5]. In general, n-vdW crystals combine the 2D structural characteristics with properties

• inherited from their parent crystals [6]. Their synthesis typically involves costly bottom-up processes. Some efforts have been successfully made to synthesize n-vdW 2D materials using liquid exfoliation techniques [7], albeit with relatively low yields. The first such material was obtained through

Unveiling the nature of atomic defects in graphene on a metal surface

• Karl Rothe,
• Nicolas Néel and
• Jörg Kröger

Beilstein J. Nanotechnol. 2024, 15, 416–425, doi:10.3762/bjnano.15.37

• ; scanning tunneling microscopy and spectroscopy; Introduction Defects in lattices of two-dimensional (2D) materials are considered as promising building blocks for tailoring electronic and phononic band structures, magnetic texture, photon emission, and charge carrier concentration [1]. In addition

• , defects profoundly impact, in a beneficial or detrimental manner, characteristic properties of 2D materials [2]. A prominent 2D material is graphene. Intact graphene, the 2D sp2 arrangement of C atoms in a honeycomb mesh, is well known for its appealing electronic and mechanical properties [3][4]. However

Graphene removal by water-assisted focused electron-beam-induced etching – unveiling the dose and dwell time impact on the etch profile and topographical changes in SiO₂ substrates

• Aleksandra Szkudlarek,
• Jan M. Michalik,
• Inés Serrano-Esparza,
• Zdeněk Nováček,
• Veronika Novotná,
• Piotr Ozga,
• Czesław Kapusta and
• José María De Teresa

Beilstein J. Nanotechnol. 2024, 15, 190–198, doi:10.3762/bjnano.15.18

• , Poland Departamento de Física de la Materia Condensada, Universidad de Zaragoza, 50009 Zaragoza, Spain Laboratorio de Microscopías Avanzadas (LMA), Universidad de Zaragoza, E-50018 Zaragoza, Spain 10.3762/bjnano.15.18 Abstract Graphene is one of the most extensively studied 2D materials, exhibiting

Upscaling the urea method synthesis of CoAl layered double hydroxides

• Camilo Jaramillo-Hernández,
• Víctor Oestreicher,
• Martín Mizrahi and
• Gonzalo Abellán

Beilstein J. Nanotechnol. 2023, 14, 927–938, doi:10.3762/bjnano.14.76

• hydroxides; layered double hydroxide; layered materials; scale-up process; synthesis; two-dimensional materials; Introduction Since the discovery of graphene [1], research on two-dimensional (2D) materials has become one of the most relevant topics in physics, chemistry, and (nano)materials science [2][3][4

Ni, Co, Zn, and Cu metal-organic framework-based nanomaterials for electrochemical reduction of CO₂: A review

• Ha Huu Do and
• Hai Bang Truong

Beilstein J. Nanotechnol. 2023, 14, 904–911, doi:10.3762/bjnano.14.74

• (2D) MOFs represent a novel addition to the family of 2D materials. Particularly, 2D MOF nanolayers with several outstanding characteristics, such as high surface area and abundant exposed active sites, have been studied for CO2RR. As a case in point, Wu et al. prepared 2D Ni-based zeolitic imidazole

Transferability of interatomic potentials for silicene

• Marcin Maździarz

Beilstein J. Nanotechnol. 2023, 14, 574–585, doi:10.3762/bjnano.14.48

• –Weber, EDIP, ReaxFF, COMB, and machine-learning-based interatomic potentials. A quantitative systematic comparison and a discussion of the results obtained are reported. Keywords: 2D materials; DFT; force fields; interatomic potentials; mechanical properties; silicene; Introduction We are living in

• graphene has also sparked interest in other non-carbon 2D materials [1][2]. One of such materials is 2D silicon, called silicene [3][4]. Using first-principles methods with current computer resources enables us to model structures up to about a few hundred atoms. For larger systems, approximate methods are

• quantify the potentials under examination. For 2D materials, directional 2D Young’s moduli, 2D Poisson’s ratios, and the 2D shear modulus, are often used instead of elastic constants Cij. Because of the symmetry of hexagonal lattices, these reduce to one 2D Young’s modulus E and one 2D Poisson’s ratio ν

Carbon nanotube-cellulose ink for rapid solvent identification

• Tiago Amarante,
• Thiago H. R. Cunha,
• Claudio Laudares,
• Ana P. M. Barboza,
• Ana Carolina dos Santos,
• Cíntia L. Pereira,
• Vinicius Ornelas,
• Bernardo R. A. Neves,
• André S. Ferlauto and
• Rodrigo G. Lacerda

Beilstein J. Nanotechnol. 2023, 14, 535–543, doi:10.3762/bjnano.14.44

• and other 1D/2D materials have been employed as ink components with great potential for a broad range of applications, for example, in flexible electronics, photoconductors, transparent conductors, and gas sensors [44][45][46][47]. Carbon nanotube ink films have been reported as field-effect

On the use of Raman spectroscopy to characterize mass-produced graphene nanoplatelets

• Keith R. Paton,
• Konstantinos Despotelis,
• Naresh Kumar,
• Piers Turner and
• Andrew J. Pollard

Beilstein J. Nanotechnol. 2023, 14, 509–521, doi:10.3762/bjnano.14.42

• .14.42 Abstract Raman spectroscopy is one of the most common methods to characterize graphene-related 2D materials, providing information on a wide range of physical and chemical properties. Because of typical sample inhomogeneity, Raman spectra are acquired from several locations across a sample, and

• , although quantification of the amount remains approximate. We therefore recommend this approach as a robust methodology for reliable characterization of mass-produced graphene-related 2D materials using confocal Raman spectroscopy. Keywords: few-layer graphene; graphene; metrology; quality control; Raman

• spectroscopy; Introduction Graphene and related 2D materials (GR2Ms) are now well established with commercial products available across a range of sectors, from sports and leisure products [1][2], through mobile phones [3] to automotive applications [4]. There are also a large number of producers of these

Liquid phase exfoliation of talc: effect of the medium on flake size and shape

• Samuel M. Sousa,
• Helane L. O. Morais,
• Joyce C. C. Santos,
• Ana Paula M. Barboza,
• Bernardo R. A. Neves,
• Elisângela S. Pinto and
• Mariana C. Prado

Beilstein J. Nanotechnol. 2023, 14, 68–78, doi:10.3762/bjnano.14.8

• applications that have specific requirements. Keywords: 2D materials; atomic force microscopy; liquid phase exfoliation; nanomaterials; talc; Introduction Two-dimensional (2D) materials have attracted a lot of interest due to their outstanding properties [1]. However, large-scale production is still a

• challenge that needs to be addressed to integrate 2D materials into industrial applications. One approach to producing large quantities of few-layer flakes of a broad range of exfoliatable materials is liquid-phase exfoliation (LPE) [2][3][4][5]. This method relies on mechanical energy to exfoliate

Photoelectrochemical water oxidation over TiO₂ nanotubes modified with MoS₂ and g-C₃N₄

• Phuong Hoang Nguyen,
• Thi Minh Cao,
• Tho Truong Nguyen,
• Hien Duy Tong and
• Viet Van Pham

Beilstein J. Nanotechnol. 2022, 13, 1541–1550, doi:10.3762/bjnano.13.127

• expensive synthesis equipment [29][36][37][38]. In this study, we compare properties and PEC water splitting efficiency of TNAs combined with the typical 2D materials MoS2 and g-C3N4 obtained with the same synthesis procedure. Insightful studies about optical and electronic properties have been conducted to

• materials (Figure 1b). This agrees with the results of previous publications in which hydrothermal methods were applied [24][25][26]. The SEM image of the g-C3N4 material shows the uniform nanosheets that were fabricated by the melamine pyrolysis method (Figure 1c). After the deposition of 2D materials MoS2

• filter cutting at 380 nm. Results and Discussion Characterizations of materials Figure 1a displays the morphology of TNAs, which have a uniform distribution of nanotubes with average diameters ranging from 80–100 nm and a length of 500 nm (Figure 1b). The MoS2 material exhibits the stacked layers of 2D