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

• , during its epitaxial growth in surface science experiments or its fabrication for applications, defects, that is, deviations from the ideal 2D lattice, inevitably occur. Examples for defects are vacancies, interstitial atoms, grain boundaries, stacking faults or wrinkles [5][6][7][8][9][10][11][12][13

• domains with ▲ and ▼ tentatively marking hcp and fcc stacking, while the dot (●) indicates the mound top site of the moiré lattice (10 mV, 5 nA, 8 nm × 8 nm). (b) Two adjacent type-1 vacancies located at an hcp (left) and an fcc (right) position of the moiré lattice (10 mV, 55 nA, 3.6 nm × 3.6 nm). Red

Classification and application of metal-based nanoantioxidants in medicine and healthcare

• Nguyen Nhat Nam,
• Nguyen Khoi Song Tran,
• Tan Tai Nguyen,
• Nguyen Ngoc Trai,
• Nguyen Phuong Thuy,
• Hoang Dang Khoa Do,
• Nhu Hoa Thi Tran and
• Kieu The Loan Trinh

Beilstein J. Nanotechnol. 2024, 15, 396–415, doi:10.3762/bjnano.15.36

• ]. The heterostructures increase surface electron deficiency, redox couples, and oxygen vacancies through an intrinsic electric field and lattice mismatch at the metal–semiconductor interface. Thus, a high level of oxygen vacancies enhances the adsorption and activation of oxygen-containing ROS, that is

• higher Ce4+ content are known to have higher CAT activity, while cerium nanomaterials with greater Ce3+ content enhance SOD activity. It was reported that Ce3+ has more oxygen vacancies providing more active sites for the binding of superoxide radicals on the surface [77][78][79]. By controlling the Ce3

Investigating ripple pattern formation and damage profiles in Si and Ge induced by 100 keV Ar⁺ ion beam: a comparative study

• Indra Sulania,
• Harpreet Sondhi,
• Tanuj Kumar,
• Sunil Ojha,
• G R Umapathy,
• Ambuj Mishra,
• Ambuj Tripathi,
• Richa Krishna,
• Devesh Kumar Avasthi and
• Yogendra Kumar Mishra

Beilstein J. Nanotechnol. 2024, 15, 367–375, doi:10.3762/bjnano.15.33

• , which confirms the near surface amorphization in Si in comparison to Ge. The main defects are the point defects such as interstitials and vacancies produced due to energy transfer between the incoming ions and the target atoms (Figure 6). The range of defect depths calculated from RBS-c spectra for Ar

Controllable physicochemical properties of WO_x thin films grown under glancing angle

• Rupam Mandal,
• Aparajita Mandal,
• Alapan Dutta,
• Rengasamy Sivakumar,
• Sanjeev Kumar Srivastava and
• Tapobrata Som

Beilstein J. Nanotechnol. 2024, 15, 350–359, doi:10.3762/bjnano.15.31

• revealed from the XRD studies, as-deposited NS-WOx films are amorphous in nature, whereas post-growth vacuum-annealed (at 673 K for 1 h) films show an amorphous-to-crystalline structural phase transition. XPS analysis confirms an increasing concentration of defect density in the form of oxygen vacancies

• conduction across the heterojunction with increasing film thickness indicates a possible role of oxygen vacancies in facilitating smooth charge transport till the thickness reaches 30 nm, above which the series resistance effect within the WOx film starts to dominate. Overall, this study demonstrates a wide

Determining by Raman spectroscopy the average thickness and N-layer-specific surface coverages of MoS₂ thin films with domains much smaller than the laser spot size

• Felipe Wasem Klein,
• Jean-Roch Huntzinger,
• Vincent Astié,
• Damien Voiry,
• Romain Parret,
• Houssine Makhlouf,
• Sandrine Juillaguet,
• Jean-Manuel Decams,
• Sylvie Contreras,
• Périne Landois,
• Ahmed-Azmi Zahab,
• Jean-Louis Sauvajol and
• Matthieu Paillet

Beilstein J. Nanotechnol. 2024, 15, 279–296, doi:10.3762/bjnano.15.26

• . However, the high temperature used in the CVD synthesis and interaction with the substrate can lead to lattice distortion and the presence of vacancies and doping. In the following, we limit our study to a number of layers N ≤ 4. Figure 4a compares the values of ΔωA−E measured on exfoliated (Figure 4a

Spatial variations of conductivity of self-assembled monolayers of dodecanethiol on Au/mica and Au/Si substrates

• Julian Skolaut,
• Jędrzej Tepper,
• Federica Galli,
• Wulf Wulfhekel and
• Jan M. van Ruitenbeek

Beilstein J. Nanotechnol. 2023, 14, 1169–1177, doi:10.3762/bjnano.14.97

• the Au surface. They are produced in the process of SAM formation by sulfur–gold bonds, which result in removing Au atoms from the top layer. This leaves the surface with Au atom vacancies that arrange into small islands of a few nanometers in size. This size matches the darker areas observed in the

Density functional theory study of Au-fcc/Ge and Au-hcp/Ge interfaces

• Olga Sikora,
• Małgorzata Sternik,
• Benedykt R. Jany,
• Franciszek Krok,
• Przemysław Piekarz and
• Andrzej M. Oleś

Beilstein J. Nanotechnol. 2023, 14, 1093–1105, doi:10.3762/bjnano.14.90

• optimized supercell shown in Figure 9d, the interface energy is slightly higher (0.395 J/m2) than that of the defect-free junction. We also tested another type of defects (Au vacancies). To construct the supercell, we first found the position of slabs with the smallest possible Au–Ge distances (two such

Isolation of cubic Si₃P₄ in the form of nanocrystals

• Polina K. Nikiforova,
• Sergei S. Bubenov,
• Vadim B. Platonov,
• Andrey S. Kumskov,
• Nikolay N. Kononov,
• Tatyana A. Kuznetsova and
• Sergey G. Dorofeev

Beilstein J. Nanotechnol. 2023, 14, 971–979, doi:10.3762/bjnano.14.80

• facile lithium transport and possess a promising capacity of 2700 and 862/737 mA·h·g−1, respectively [16][17]. In the case of the synthesized nanoscale particles, a high level of Li mobility can be reached because of their developed surface and the interconnected ordered network of silicon vacancies with

The microstrain-accompanied structural phase transition from h-MoO₃ to α-MoO₃ investigated by in situ X-ray diffraction

• Zeqian Zhang,
• Honglong Shi,
• Boxiang Zhuang,
• Minting Luo and
• Zhenfei Hu

Beilstein J. Nanotechnol. 2023, 14, 692–700, doi:10.3762/bjnano.14.55

• from +2 to +6 [1][2], leading to a range of molybdenum oxides. Molybdenum oxides include the fully stoichiometric MoO3 with a large bandgap above 2.7 eV, the reduced oxides MoO3−x with oxygen vacancies, and the semimetal MoO2. The degree of reduction influences the bandgap energy of molybdenum oxides

Humidity-dependent electrical performance of CuO nanowire networks studied by electrochemical impedance spectroscopy

• Jelena Kosmaca,
• Juris Katkevics,
• Jana Andzane,
• Raitis Sondors,
• Liga Jasulaneca,
• Raimonds Meija,
• Kiryl Niherysh,
• Yelyzaveta Rublova and
• Donats Erts

Beilstein J. Nanotechnol. 2023, 14, 683–691, doi:10.3762/bjnano.14.54

• nanowires synthesized by thermal annealing of copper are a p-type semiconductor material [9][12][14]; its majority charge carriers are positive holes (h+) related to the presence of Cu vacancies or impurities. Under dry conditions, possible ionosorption of oxygen species from air on the nanowire surface

Titania nanoparticles for photocatalytic degradation of ethanol under simulated solar light

• Evghenii Goncearenco,
• Iuliana P. Morjan,
• Claudiu Teodor Fleaca,
• Florian Dumitrache,
• Elena Dutu,
• Monica Scarisoreanu,
• Valentin Serban Teodorescu,
• Alexandra Sandulescu,
• Crina Anastasescu and
• Ioan Balint

Beilstein J. Nanotechnol. 2023, 14, 616–630, doi:10.3762/bjnano.14.51

• indicate changes regarding the variation of the nanoparticle surfaces according to the value of the working pressure. Since XPS analysis is a surface measurement and the samples were calcined in air, the possibility to identify the presence of Ti3+ species and oxygen vacancies is small, but we do not

• donor levels, for example chlorine atoms [66], but most probably they are acceptor levels created by titanium vacancies [67][68]. Band-to-band transitions have not been detected as separate PL bands, taking into account the obtained bandgap values from the optical properties. But, they are surely a part

• of the complex PL band at 400 nm, the resolution of which into the components requires another investigation. Oxygen and titanium vacancies have been found. These points defects are created most probably at the surface of the powder particles because in the HRTEM figures we do not see any dislocation

Molecular nanoarchitectonics: unification of nanotechnology and molecular/materials science

• Katsuhiko Ariga

Beilstein J. Nanotechnol. 2023, 14, 434–453, doi:10.3762/bjnano.14.35

• synthesize 8-carbon armchair graphene nanoribbons and nanographene C66 with periodic vacancies on the surface (Figure 8) [124]. Detailed processes of the surface synthesis of 5,8-dibromobenzene molecules kept at room temperature after deposition on Au(111) were disclosed through STM observations

• conversion of polymer chains to 8-carbon armchair graphene nanoribbons was observed to be efficient at the Au(111) monatomic step at around 670–720 K. The asymmetric distribution of periodic vacancies can form frontier orbitals with wiggly and linear geometries. On-surface synthetic nanoarchitectonics may

• lead to a variety of nonplanar graphene nanoribbons with periodic atomic vacancies. Molecular nanoarchitectonics by on-surface synthesis is a powerful tool for structures other than nanographene. Various functional units can be freely combined to obtain new nanostructures. However, it is generally

Plasmonic nanotechnology for photothermal applications – an evaluation

• A. R. Indhu,
• L. Keerthana and
• Gnanaprakash Dharmalingam

Beilstein J. Nanotechnol. 2023, 14, 380–419, doi:10.3762/bjnano.14.33

Bismuth-based nanostructured photocatalysts for the remediation of antibiotics and organic dyes

• Akeem Adeyemi Oladipo and
• Faisal Suleiman Mustafa

Beilstein J. Nanotechnol. 2023, 14, 291–321, doi:10.3762/bjnano.14.26

• ][104][110][144][145][146][147][148][149][150]. Doping reduces the bandgap energy, introduces intermediate energy levels to overcome constraints, creates trap sites to capture photogenerated charge carriers, and increases the absorption of visible light. Additionally, after doping, oxygen vacancies or

Gap-directed chemical lift-off lithographic nanoarchitectonics for arbitrary sub-micrometer patterning

• Chang-Ming Wang,
• Hong-Sheng Chan,
• Chia-Li Liao,
• Che-Wei Chang and
• Wei-Ssu Liao

Beilstein J. Nanotechnol. 2023, 14, 34–44, doi:10.3762/bjnano.14.4

• -streptavidin antibodies to the biotin moieties. In these tests, 11-mercaptoundecanol (MCU) molecules on an Au surface are selectively removed by the oxygen plasma activated PDMS stamp at stamp-substrate contact regions. BAT molecules are thereafter backfilled into the exposed surface vacancies, and the biotin

A TiO₂@MWCNTs nanocomposite photoanode for solar-driven water splitting

• Anh Quynh Huu Le,
• Ngoc Nhu Thi Nguyen,
• Hai Duy Tran,
• Van-Huy Nguyen and
• Le-Hai Tran

Beilstein J. Nanotechnol. 2022, 13, 1520–1530, doi:10.3762/bjnano.13.125

• non-smooth walls of the MWCNTs indicates the presence of defects such as vacancies, dangling bonds, interstitials, and pentagons [14]. Figure 3b shows the irregular shape of TiO2 particles smaller than 20 nm and their non-uniform distribution. In Figure 3c, some MWCNTs link with TiO2 clusters as

• calculated as 3.14 and 2.51 eV, respectively. The results show that the lower bandgap of TiO2@MWCNTs catalyst could derive from vacancies on the MWCNTs or the interaction between TiO2 and MWCNTs [25]. Moreover, the C–O–Ti linkages on the TiO2@MWCNs contribute to the extension of the absorption of light at a

• transforms into rutile. This could be due to the carbon components on the MWCNTs acting as a robust reducing agent for facilitating the transformation from anatase to rutile TiO2 by forming oxygen vacancies [30]. Generally, the capacitance of the photoelectrochemical electrode is associated with the

Structural studies and selected physical investigations of LiCoO₂ obtained by combustion synthesis

• Monika Michalska,
• Paweł Ławniczak,
• Tomasz Strachowski,
• Adam Ostrowski and
• Waldemar Bednarski

Beilstein J. Nanotechnol. 2022, 13, 1473–1482, doi:10.3762/bjnano.13.121

• given in the literature on the layered structure. The lattice constants depend on the fraction of vacancies and the mixing of Li/Co positions. There were no significant changes of the lattice constants a and c as functions of the temperature and size of the crystallites. Specific surface area

LED-light-activated photocatalytic performance of metal-free carbon-modified hexagonal boron nitride towards degradation of methylene blue and phenol

• Nirmalendu S. Mishra and
• Pichiah Saravanan

Beilstein J. Nanotechnol. 2022, 13, 1380–1392, doi:10.3762/bjnano.13.114

• nitrogen vacancies and formation of energy sub-bands which help in overall reduction of the bandgap energy (Eg) [14]. At the same time, the incorporation of carbon into the HBN lattice results in the delocalization of electrons with simultaneous reduction in bandgap and is directly dependent upon the

Recent trends in Bi-based nanomaterials: challenges, fabrication, enhancement techniques, and environmental applications

• Vishal Dutta,
• Ankush Chauhan,
• Ritesh Verma,
• C. Gopalkrishnan and
• Van-Huy Nguyen

Beilstein J. Nanotechnol. 2022, 13, 1316–1336, doi:10.3762/bjnano.13.109

• type of halogen used. The activation of otherwise inert CO2 and H2O molecules is greatly aided by the ease with which photoinduced oxygen vacancies (OVs) are produced on the surface [25]. The excellent photocatalytic performance can be attributed to the layered crystal structures and small bandgap

• , heterostructure formation, interface modification, and Bi-content enhancement, have been employed. Defect formation Vacancies and defects affect the electrical properties of Bi-based semiconductor photocatalysts and, hence, govern the photocatalytic efficacy. Rao et al. reported an N2-assisted heat treatment

• vacancies in monolayered Bi2WO6 nanosheets with a thickness of 1.0 nm have recently been shown [82]. The Bi defects were shown to promote the adsorption and activation of reactant molecules, which reduced the energy barrier even more. The photocatalytic performance corroborated this. The presence of

Rapid fabrication of MgO@g-C₃N₄ heterojunctions for photocatalytic nitric oxide removal

• Minh-Thuan Pham,
• Duyen P. H. Tran,
• Xuan-Thanh Bui and
• Sheng-Jie You

Beilstein J. Nanotechnol. 2022, 13, 1141–1154, doi:10.3762/bjnano.13.96

• atoms [64][65][66]. Also, Liang and co-workers reported that the recombination of the e−–h+ pairs could be inhibited by doping MgO into g-C3N4 [32]. When MgO is added, the defect concentration increases and Mg and O vacancies are generated in MgO@g-C3N4. These defects work as the electron traps, which

• and 5% MgO@g-C3N4 in the visible and UV range, which increased the photocatalytic performance under visible light irradiation. The PL results confirmed the presence of vacancies in the MgO@g-C3N4 heterojunctions. MgO@g-C3N4 is promising for large-scale fabrication via this simple and fast method. This

Theoretical investigations of oxygen vacancy effects in nickel-doped zirconia from ab initio XANES spectroscopy at the oxygen K-edge

• Dick Hartmann Douma,
• Lodvert Tchibota Poaty,
• Alessio Lamperti,
• Stéphane Kenmoe,
• Abdulrafiu Tunde Raji,
• Alberto Debernardi and
• Bernard M’Passi-Mabiala

Beilstein J. Nanotechnol. 2022, 13, 975–985, doi:10.3762/bjnano.13.85

• Nanotechnologies, Institut National de Recherche en Sciences Exactes et Naturelles (IRSEN), Brazzaville, Congo 10.3762/bjnano.13.85 Abstract In this study, we present theoretical X-ray absorption near-edge structure (XANES) spectra at the K-edge of oxygen in zirconia containing Ni dopant atoms and O vacancies at

• vacancies. In this system, each Ni atom is surrounded by two shells of O with tetrahedral geometry, in a similar way as in bulk cubic zirconia. The oxygen K-edge XANES spectrum of this configuration shows a pre-edge peak, which is attributable to dipole transitions from O 1s to O 2p states that are

• one remains in a tetrahedral geometry. Furthermore, the introduction of two vacancies in the 2Ni-doped zirconia results in the two Ni atoms having distorted octahedral and trigonal bipyramidal geometries and being coupled antiferromagnetically in the ground state. Additionally, the oxygen K-edge XANES

Hierarchical Bi₂WO₆/TiO₂-nanotube composites derived from natural cellulose for visible-light photocatalytic treatment of pollutants

• Zehao Lin,
• Zhan Yang and
• Jianguo Huang

Beilstein J. Nanotechnol. 2022, 13, 745–762, doi:10.3762/bjnano.13.66

• three weak peaks at 448, 479, and 490 nm, which are indexed to the recombination of photoinduced electron−hole pairs, freely excited electrons, surface defects, and oxygen vacancies on the band edges, respectively [36][61]. It is apparent that the PL intensities of the Bi2WO6/TiO2-NT nanocomposites at

Sodium doping in brookite TiO₂ enhances its photocatalytic activity

• Boxiang Zhuang,
• Honglong Shi,
• Honglei Zhang and
• Zeqian Zhang

Beilstein J. Nanotechnol. 2022, 13, 599–609, doi:10.3762/bjnano.13.52

• structure and produce microstructures such as the core–shell structure, local lattice distortion, interstitial atoms, and atomic vacancies, which are critical to its excellent photocatalytic activity. Keywords: brookite titanium dioxide; core–shell structure; photocatalytic activity; sodium doping; twins

• atomic pair distribution function based on electron diffraction. High-resolution transmission electron microscopy results revealed the existence of a core–shell structure, lattice distortion, interstitial atoms, and atomic vacancies in NaxTi1−xO2, which is critical for an excellent photocatalytic

• including the core–shell structure, the nanodomain, interstitial atoms, atomic vacancies, and complex defects can be frequently observed in the samples calcinated at 300 and 400 °C but rarely for other samples calcinated at higher temperatures. Since the higher calcinating temperature can improve the atomic

Revealing local structural properties of an atomically thin MoSe₂ surface using optical microscopy

• Lin Pan,
• Peng Miao,
• Anke Horneber,
• Alfred J. Meixner,
• Pierre-Michel Adam and
• Dai Zhang

Beilstein J. Nanotechnol. 2022, 13, 572–581, doi:10.3762/bjnano.13.49

• effects strongly influence the optical and electronic properties of 2D-TMDC materials. Optical second harmonic generation (SHG) spectroscopy has been recently used to study the presence of mid-gap states in the electronic band structure of WS2 flakes, which are induced by sulfur vacancies [14]. In

Zinc oxide nanostructures for fluorescence and Raman signal enhancement: a review

• Ioana Marica,
• Fran Nekvapil,
• Maria Ștefan,
• Cosmin Farcău and
• Alexandra Falamaș

Beilstein J. Nanotechnol. 2022, 13, 472–490, doi:10.3762/bjnano.13.40

• a long time. It was assumed that zinc vacancies, oxygen vacancies, and other defects are candidates for recombination centres involved in the visible luminescence [78]. Studies concerning the green luminescence of ZnO in the past few years assumed that the oxygen vacancies are the most likely

• candidates for recombination centres involved in the visible luminescence of ZnO [77][79]. Thus, the electrical and luminescence characteristics of zinc oxide could be changed by the number of oxygen vacancies or other point defects (vacancies, atom substitutions, and interstitial atoms). Moreover

• also benefits the SERS enhancement. Doping zinc oxide–Ag nanoparticles with magnesium also introduces defect sites (surface defects and oxygen vacancies), which form new energy levels below the conduction band of zinc oxide, facilitating the charge transfer mechanism. In this case, besides the charge