The preparation temperature influences the physicochemical nature and activity of nanoceria

• Robert A. Yokel,
• Wendel Wohlleben,
• Johannes Georg Keller,
• Matthew L. Hancock,
• Jason M. Unrine,
• D. Allan Butterfield and
• Eric A. Grulke

Beilstein J. Nanotechnol. 2021, 12, 525–540, doi:10.3762/bjnano.12.43

• fewer oxygen vacancies and exhibits, therefore, a predominance of surface Ce+4, compared to a solvothermally synthesized nanoceria material with more oxygen vacancies, which produce a preponderance of surface Ce+3, it was hypothesized the NM-212 would have less catalytic activity. Another nanoscale

• +. Increased Ce3+ is accompanied by an increase in oxygen vacancies that weaken the crystal lattice [14]. According to the dissolution framework by Gray and co-workers, Ce3+ can follow more dissolution pathways (including oxidative dissolution) than Ce4+ [59]. The much greater percentage of Ce3+ on the surface

Interface interaction of transition metal phthalocyanines with strontium titanate (100)

• Reimer Karstens,
• Thomas Chassé and
• Heiko Peisert

Beilstein J. Nanotechnol. 2021, 12, 485–496, doi:10.3762/bjnano.12.39

• increased by introducing oxygen vacancies into the crystal structure or by doping (e.g., n-type doping with niobium, Nb5+). Generally, two different terminations of STO(100) are known, that is, the surface can be either TiO2- or SrO-terminated. The TiO2 termination can be achieved by (ex situ) acid

Nickel nanoparticle-decorated reduced graphene oxide/WO₃ nanocomposite – a promising candidate for gas sensing

• Ilka Simon,
• Alexandr Savitsky,
• Rolf Mülhaupt,
• Vladimir Pankov and
• Christoph Janiak

Beilstein J. Nanotechnol. 2021, 12, 343–353, doi:10.3762/bjnano.12.28

• graphene oxide, rGO) chemically or thermally. Through the partial removal of oxygen groups, the conductivity can be restored. Additionally, defects and vacancies are created [26]. Because of the ultra-high surface area per atom and the high electron transport along the graphene plane, rGO has a rapid and

Exploring the fabrication and transfer mechanism of metallic nanostructures on carbon nanomembranes via focused electron beam induced processing

• Christian Preischl,
• Linh Hoang Le,
• Elif Bilgilisoy,
• Armin Gölzhäuser and
• Hubertus Marbach

Beilstein J. Nanotechnol. 2021, 12, 319–329, doi:10.3762/bjnano.12.26

• ) [13], thin layers of porphyrin molecules [14][15], and surface-anchored metal-organic frameworks (SURMOFs) [16][17]. For oxide surfaces it is known that the activation mechanism is based on reactive oxygen vacancies, which are locally created by electron-stimulated oxygen desorption [18][19]. Whereas

Extended iron phthalocyanine islands self-assembled on a Ge(001):H surface

• Rafal Zuzak,
• Marek Szymonski and
• Szymon Godlewski

Beilstein J. Nanotechnol. 2021, 12, 232–241, doi:10.3762/bjnano.12.19

• defects could be identified within the surface [61][62][63][64][65]. These are mainly single or double hydrogen vacancies. This means that within a Ge dimer either one hydrogen atom is missing, this is called a single dangling bond (DB), or the dimer lacks both hydrogen atoms and the so-called dangling

Fusion of purple membranes triggered by immobilization on carbon nanomembranes

• René Riedel,
• Natalie Frese,
• Fang Yang,
• Martin Wortmann,
• Raphael Dalpke,
• Daniel Rhinow,
• Norbert Hampp and
• Armin Gölzhäuser

Beilstein J. Nanotechnol. 2021, 12, 93–101, doi:10.3762/bjnano.12.8

• only a few vacancies could be obtained. Assembly of a stable hybrid membrane The experiments were repeated with a genetically modified species of c-His PM. This species has histidine-tags on every BR molecule and hence is strongly positively charged on the extracellular side. Thus, a chemical complex

• maintain high substrate coverage despite low OD, the incubation was repeated four times. Despite the reduction of optical density, large areas of merged c-His PM monolayer could be observed as shown in Figure 3. The fused PM sheets showed small vacancies and fissures, however, the constant height of 5.0

• solution. The absorption peak at 570 nm indicates that BR is functional. (a–c) Large-area agglomerates of c-His PM forming an immobilized quasi-monolayer with only a few vacancies on a functionalized NBPT CNM. (d) The electrostatic potential of the area shown in (c) reveals a uniform orientation of c-His

ZnO and MXenes as electrode materials for supercapacitor devices

• Ameen Uddin Ammar,
• Ipek Deniz Yildirim,
• Feray Bakan and
• Emre Erdem

Beilstein J. Nanotechnol. 2021, 12, 49–57, doi:10.3762/bjnano.12.4

• point defects. PL yields defect-related emission from all possible defects whereas EPR reveals only signals from paramagnetic defects [7]. Therefore, using EPR one obtains signals from the vacancies or interstitials that are ionized and become paramagnetic. In ZnO, singly ionized oxygen vacancies are

• changes in the Raman spectrum. In particular, this method is used for carbon materials to detect the so-called D-band, which belongs to sp3-hybridized carbon. For the occurrence of the D-band either C dangling bonds on the surface, C interstitials, or C vacancies need to exist. Raman spectra of metal

• ionized oxygen vacancies located either in volume or at the surface of the material. (b) PL spectra showing all possible defect centers, including non-paramagnetic ones. The defects emit visible light yielding a broad emission band [4]. (c) Tauc plot obtained from UV–vis reflectance measurements

Unravelling the interfacial interaction in mesoporous SiO₂@nickel phyllosilicate/TiO₂ core–shell nanostructures for photocatalytic activity

• Bridget K. Mutuma,
• Xiluva Mathebula,
• Isaac Nongwe,
• Bonakele P. Mtolo,
• Boitumelo J. Matsoso,
• Rudolph Erasmus,
• Zikhona Tetana and
• Neil J. Coville

Beilstein J. Nanotechnol. 2020, 11, 1834–1846, doi:10.3762/bjnano.11.165

• that facilitates easy adsorption of organic molecules and their transfer onto the active sites of TiO2 [22][23]. Additionally, the interaction between SiO2 and TiO2 could result in the creation of oxygen vacancies that promote charge-transfer processes and, hence, enhance the photocatalytic activity

• electronegativity and ionic radius between the metal ions and titania can alter the concentration of oxygen vacancies in the TiO2 lattice. Hence, the higher electronegativity of Ni2+ in NiPS [43] can induce defect sites within the structure and, consequently, alter light absorption and charge-transfer processes [51

• ][67]. These oxygen vacancies easily act as hole traps that lower the charge-carrier recombination rate, resulting in more free electrons that can give rise to more superoxide radicals upon reaction with adsorbed surface oxygen [23]. Furthermore, the flake-like NiPS morphology could act as a suitable

Nanocasting synthesis of BiFeO₃ nanoparticles with enhanced visible-light photocatalytic activity

• Thomas Cadenbach,
• Maria J. Benitez,
• A. Lucia Morales,
• Cesar Costa Vera,
• Luis Lascano,
• Francisco Quiroz,
• Alexis Debut and
• Karla Vizuete

Beilstein J. Nanotechnol. 2020, 11, 1822–1833, doi:10.3762/bjnano.11.164

• to point out that a comparison of bandgap values with different BiFeO3 samples is very difficult as particle shape, size, phase purity, as well as oxygen vacancies have a strong impact on the electronic structure of the resulting material. Photocatalytic activity The photocatalytic activity of all

Oxidation of Au/Ag films by oxygen plasma: phase separation and generation of nanoporosity

• Abdel-Aziz El Mel,
• Said A. Mansour,
• Mujaheed Pasha,
• Atef Zekri,
• Janarthanan Ponraj,
• Akshath Shetty and
• Yousef Haik

Beilstein J. Nanotechnol. 2020, 11, 1608–1614, doi:10.3762/bjnano.11.143

• silver and gold. In addition, it was shown that the preferential oxidation of silver resulted in a solid-state diffusion of silver toward the surface where it oxidized and formed nanoporous microspheres. The gold phase remaining in the film exhibited nanoporosity due to the injected vacancies at the

• silver oxide, its concentration was low inside the film. This indicates that the majority of the silver atoms diffused out of the film leaving behind a gold-rich nanoporous scaffold. The nanoporosity in the gold film probably resulted from the generation of vacancies within the film during the oxidation

• film can be explained by the Kirkendall effect [24]. More precisely, as silver diffuses out of the alloy film, vacancies are injected into the metal/oxide interface and migrate within the fast-diffusing medium (represented here by the metal alloy in Figure 8c). As the oxidation process evolves

Wafer-level integration of self-aligned high aspect ratio silicon 3D structures using the MACE method with Au, Pd, Pt, Cu, and Ir

• Mathias Franz,
• Romy Junghans,
• Paul Schmitt,
• Adriana Szeghalmi and
• Stefan E. Schulz

Beilstein J. Nanotechnol. 2020, 11, 1439–1449, doi:10.3762/bjnano.11.128

• electron vacancies play an important role within the anodic reactions at the silicon surface. The combined reaction can be written as: This reaction summarises two etching mechanisms related to n, the number of consumed holes h+ per etched Si atom. The first mechanism is correlated to n = 4. The silicon

Atomic defect classification of the H–Si(100) surface through multi-mode scanning probe microscopy

• Jeremiah Croshaw,
• Thomas Dienel,
• Taleana Huff and
• Robert Wolkow

Beilstein J. Nanotechnol. 2020, 11, 1346–1360, doi:10.3762/bjnano.11.119

• speculated a variety of origins for this defect, including a negatively charged As dopant [58], Si-vacancy hydrogen complexes [9], and B dopants [59][60]. Crystal vacancies have previously been identified in other materials using scanning probe microscopy including Ga vacancies in GaAs [61], As vacancies in

• GaAs [62], and P vacancies in InP(110) [63]. Due to the common nature of these defects in other semiconductors and the similarity in imaging character, we thus attribute this defect to most likely be a Si vacancy. Further discussion of our assignment and additional evidence is given later as part of

• localized negative charge (similar to the dark halo around a DB in Figure 2a-1 or the vacancies in Figure 4). At this point, one could be tempted to assign the dark feature to the same vacancy defect as in Figure 4 due to their similar likeness. However, this species is found to be unstable and irreversibly

Effect of localized helium ion irradiation on the performance of synthetic monolayer MoS₂ field-effect transistors

• Jakub Jadwiszczak,
• Pierce Maguire,
• Conor P. Cullen,
• Georg S. Duesberg and
• Hongzhou Zhang

Beilstein J. Nanotechnol. 2020, 11, 1329–1335, doi:10.3762/bjnano.11.117

• improvement of both the carrier mobility in the transistor channel and the electrical conductance of the MoS2, due to doping with ion beam-created sulfur vacancies. Larger areal irradiations introduce a higher concentration of scattering centers, hampering the electrical performance of the device. In addition

• , we find that irradiating the electrode–channel interface has a deleterious impact on charge transport when contrasted with irradiations confined only to the transistor channel. Keywords: 2D materials; contacts; defect engineering; helium ion microscope; ion beam doping; vacancies; two-dimensional

• of well-performing monolayer TMD films [3][4][5], leading to viable large-scale integration of on-chip TMD FETs. With device miniaturization, it becomes key to understand the impact of defects such as chalcogen vacancies on the electrical transport properties of FETs based on 2D semiconductors. This

Structural and electronic properties of SnO₂ doped with non-metal elements

• Jianyuan Yu,
• Yingeng Wang,
• Yan Huang,
• Xiuwen Wang,
• Jing Guo,
• Jingkai Yang and
• Hongli Zhao

Beilstein J. Nanotechnol. 2020, 11, 1321–1328, doi:10.3762/bjnano.11.116

• oxygen vacancies, and thus, increase the charge density of the Sn sites. The replacement of O with N can simultaneously decrease the release of CO2. While there are reports on experiments regarding the doping of SnO2 with non-metal elements, the mechanism of the effect of non-metal element doping on the

Adsorption behavior of tin phthalocyanine onto the (110) face of rutile TiO₂

• Lukasz Bodek,
• Mads Engelund,
• Aleksandra Cebrat and
• Bartosz Such

Beilstein J. Nanotechnol. 2020, 11, 821–828, doi:10.3762/bjnano.11.67

• molecule towards the surface. Also, the electrostatic landscape of a reduced rutile (110) surface prepared in UHV by sputter–anneal cycles is complicated. The cleaning procedure creates oxygen vacancies, which in turn leads to the formation of polarons near the surface [29][30][31]. Additionally, water

• molecules may dissociate at oxygen vacancies and form hydroxy groups on the surface. Both species can be recognized in our STM images and they both lead to the formation of dipole moments pointing away from the surface [32]. Their local arrangement may play a significant role in the interaction between a

Hexagonal boron nitride: a review of the emerging material platform for single-photon sources and the spin–photon interface

• Stefania Castelletto,
• Faraz A. Inam,
• Shin-ichiro Sato and
• Alberto Boretti

Beilstein J. Nanotechnol. 2020, 11, 740–769, doi:10.3762/bjnano.11.61

• /compatibility of the active quantum source and the device in use, and they have limitations in terms of scalability. The type of point defects that should be addressed is also a key element and is generally substitutional dopants, native vacancies, and dopant-vacancy complexes. The space of possible defects is

Effect of Ag loading position on the photocatalytic performance of TiO₂ nanocolumn arrays

• Jinghan Xu,
• Yanqi Liu and
• Yan Zhao

Beilstein J. Nanotechnol. 2020, 11, 717–728, doi:10.3762/bjnano.11.59

• the catalyst, so the catalyst needs to have a certain adsorption capacity for dye molecules. Due to the presence of oxygen vacancies, the surface of TiO2 is usually negatively charged and has a good adsorption capacity for cationic dye molecules [36]. Commonly used cationic dyes are rhodamine, methyl

Effect of substitutional defects on resonant tunneling diodes based on armchair graphene and boron nitride nanoribbons lateral heterojunctions

• Majid Sanaeepur

Beilstein J. Nanotechnol. 2020, 11, 688–694, doi:10.3762/bjnano.11.56

• between graphene and hBN [3]. However, inevitable interfacial defects located at the interface of Gr/hBN heterojunctions, including point defects (single vacancies and substitutional defects) and topological defects can alter the electronic properties of Gr/hBN heterostructures and, consequently, the

DFT calculations of the structure and stability of copper clusters on MoS₂

• Cara-Lena Nies and
• Michael Nolan

Beilstein J. Nanotechnol. 2020, 11, 391–406, doi:10.3762/bjnano.11.30

• are 5.4 eV for Cu, 4.2 eV for Ag and 4.5 eV for Au. The presence of a complete row of sulfur vacancies enhances the adsorption energy of the nanoparticles for all three metals, increasing it to 7.1 eV, 7.0 eV and 6.0 eV for Cu, Ag and Au, respectively. It also increases the charge transfer from the

• particular when the monolayer is defect-rich. MoS2 is known to be naturally high in defects [21][32], in particular S vacancies. It has been predicted that S vacancies in a MoS2 monolayer are most stable when they occur in a row, with a decrease in the vacancy formation energy as the number of vacancies

• increases [2]. Experimental methods for controlling the formation of sulfur vacancies in the MoS2 monolayer have also been developed [33], and this would allow for the targeted use of S vacancies to enhance desired properties such as adsorption energy. In this study we aim to fill the gap in the literature

Nonequilibrium Kondo effect in a graphene-coupled quantum dot in the presence of a magnetic field

• Levente Máthé and
• Ioan Grosu

Beilstein J. Nanotechnol. 2020, 11, 225–239, doi:10.3762/bjnano.11.17

• Kondo screening of magnetic impurities in graphene [75]. They found an asymmetric behavior of the Kondo temperature depending on the sign of the chemical potential in the limit of U → ∞. Experimental measurements of the Kondo effect produced by lattice vacancies in graphene layers reveal high values of

• on the bias voltage is in agreement with the theoretical results of Świrkowicz et al., who considered a QD connected to metallic electrodes [31]. The zero-bias peak of the differential conductance was observed experimentally for magnetic impurities induced by vacancies on graphite surface [77]. In

Antimony deposition onto Au(111) and insertion of Mg

• Lingxing Zan,
• Da Xing,
• Abdelaziz Ali Abd-El-Latif and
• Helmut Baltruschat

Beilstein J. Nanotechnol. 2019, 10, 2541–2552, doi:10.3762/bjnano.10.245

• epitaxial 2D growth occurs to form the row structure with the width of ≈2.4 or ≈3.2 nm and the height of 0.35 nm. The angle between the two different oriented domains is around 120°, which suggests that they are probably aligned along the densely packed (111) rows of the substrate. Some vacancies appeared

Deterministic placement of ultra-bright near-infrared color centers in arrays of silicon carbide micropillars

• Stefania Castelletto,
• Abdul Salam Al Atem,
• Faraz Ahmed Inam,
• Hans Jürgen von Bardeleben,
• Sophie Hameau,
• Ahmed Fahad Almutairi,
• Gérard Guillot,
• Shin-ichiro Sato,
• Alberto Boretti and
• Jean Marie Bluet

Beilstein J. Nanotechnol. 2019, 10, 2383–2395, doi:10.3762/bjnano.10.229

• enhancement of the optical emission between 850 and 1400 nm of an ensemble of silicon mono-vacancies (VSi), silicon and carbon divacancies (VCVSi), and nitrogen vacancies (NCVSi) in an n-type 4H-SiC array of micropillars. The micropillars have a length of ca. 4.5 μm and a diameter of ca. 740 nm, and were

• ; Introduction Silicon carbide (SiC) is an established material for many electronic devices and has also been considered for photonics applications recently. After the improvement of the purity of the material and the isolation of point defects (primarily vacancies), SiC has been considered to host physical

• near-infrared color centers in SiC using hydrogen irradiation and annealing at different temperatures. We have optimized the enhancement of color centers relevant for quantum sensing applications, such as silicon monovacancies and divacancies, and nitrogen vacancies. Due to the high fluence during

Multiwalled carbon nanotube based aromatic volatile organic compound sensor: sensitivity enhancement through 1-hexadecanethiol functionalisation

• Nadra Bohli,
• Meryem Belkilani,
• Juan Casanova-Chafer,
• Eduard Llobet and
• Adnane Abdelghani

Beilstein J. Nanotechnol. 2019, 10, 2364–2373, doi:10.3762/bjnano.10.227

• decoration of MWCNTs Prior to their deposition on the interdigitated electrode surface, the MWCNTs were treated by oxygen plasma to create oxygen vacancies on the walls of the CNTs in order to enhance their surface reactivity [14][15]. The detailed description of the experimental steps undertaken is

Improved adsorption and degradation performance by S-doping of (001)-TiO₂

• Xiao-Yu Sun,
• Xian Zhang,
• Xiao Sun,
• Ni-Xian Qian,
• Min Wang and
• Yong-Qing Ma

Beilstein J. Nanotechnol. 2019, 10, 2116–2127, doi:10.3762/bjnano.10.206

• % to 68.5% due to the synergistic effects of the oxygen vacancies, increased number of surface chemical adsorption centers as a result of SO42− adsorption on the TiO2 surface and the larger pore size. (3) S-doping increases the MB degradation rate from 6.9 × 10−2 min−1 to 18.2 × 10−2 min−1 due to an

• , the XP spectrum of O 1s can be fitted by three peaks and the CSs correspond to TiO2, –OH and oxygen vacancies (Ov) [44]. As the RS/Ti increases, the ratio of Ov increases from 4.3% (2-S0) to 22.9% (2-S3) and then decreases again to 19.9% (2-S5) (Table 3). The XPS signals of the oxygen vacancies were

• the O 2p orbitals. At the same time, the ratio of the Ov increases in the order of 2-S0.5 < 2-S1 < 2-S5 < 2-S3, as given in Table 3; therefore, the decrease of the DOS mainly results from an increase of the ratio of oxygen vacancies. Figure 6 shows the UV–vis DRS of 2-S0, 2-S0.5, 2-S1, 2-S3 and 2-S5

Synthesis of highly active ETS-10-based titanosilicate for heterogeneously catalyzed transesterification of triglycerides

• Muhammad A. Zaheer,
• David Poppitz,
• Khavar Feyzullayeva,
• Marianne Wenzel,
• Jörg Matysik,
• Radomir Ljupkovic,
• Aleksandra Zarubica,
• Alexander A. Karavaev,
• Andreas Pöppl,
• Roger Gläser and
• Muslim Dvoyashkin

Beilstein J. Nanotechnol. 2019, 10, 2039–2061, doi:10.3762/bjnano.10.200

• vacancies are partially removed due to the detitanation process. This can additionally contribute to the decrease in the observed intensities of NH3 desorption below 600 K for treated samples compared to Na,K-ETS-10. At temperatures above 600 K, highly pronounced NH3 desorption, presumably from the surface