Tm-doped TiO₂ and Tm₂Ti₂O₇ pyrochlore nanoparticles: enhancing the photocatalytic activity of rutile with a pyrochlore phase

• Desiré M. De los Santos,
• Javier Navas,
• Teresa Aguilar,
• Antonio Sánchez-Coronilla,
• Concha Fernández-Lorenzo,
• Rodrigo Alcántara,
• Jose Carlos Piñero,
• Ginesa Blanco and
• Joaquín Martín-Calleja

Beilstein J. Nanotechnol. 2015, 6, 605–616, doi:10.3762/bjnano.6.62

• oxygen vacancies is interesting for photocatalytic applications because, for example, an increase in oxygen vacancies generates more surface defects on the synthesized nanoparticles. This can be studied from the O 1s XPS spectra. Figure 2c (bottom) shows the different contributions in the O 1s spectrum

In situ scanning tunneling microscopy study of Ca-modified rutile TiO₂(110) in bulk water

• Giulia Serrano,
• Beatrice Bonanni,
• Tomasz Kosmala,
• Marco Di Giovannantonio,
• Ulrike Diebold,
• Klaus Wandelt and
• Claudio Goletti

Beilstein J. Nanotechnol. 2015, 6, 438–443, doi:10.3762/bjnano.6.44

• average density of surface defects (about 10% [10]) is sufficient to provide the adsorption sites necessary to produce the 2D network observed in UHV [1][5]. The rows which are still on the surface after the first stage of immersion in water are thus formed by Ca bound to the preferred adsorption sites

Morphology, structural properties and reducibility of size-selected CeO_2−x nanoparticle films

• Maria Chiara Spadaro,
• Sergio D’Addato,
• Gabriele Gasperi,
• Francesco Benedetti,
• Paola Luches,
• Vincenzo Grillo,
• Giovanni Bertoni and
• Sergio Valeri

Beilstein J. Nanotechnol. 2015, 6, 60–67, doi:10.3762/bjnano.6.7

• due to the presence of Ce3+ ions. Non-stoichiometric NPs grown in this way exhibit a higher catalytic activity than stoichiometric material, mainly because of surface defects and chemisorbed oxygen [13][14]. A new interpretation for the redox activity of CeO2−x NPs has been recently proposed, based on

Inorganic Janus particles for biomedical applications

• Isabel Schick,
• Steffen Lorenz,
• Dominik Gehrig,
• Stefan Tenzer,
• Wiebke Storck,
• Karl Fischer,
• Dennis Strand,
• Frédéric Laquai and
• Wolfgang Tremel

Beilstein J. Nanotechnol. 2014, 5, 2346–2362, doi:10.3762/bjnano.5.244

• ], the gold nanoparticles were functionalized with 1-octadecanethiol to suppress multiple nucleation of manganese oxide on different crystal facets or surface defects. This surface functionalization was proved not to be necessary for Au@Fe3O4 heterodimers. The morphology as well as the sizes of the metal

Cathode lens spectromicroscopy: methodology and applications

• T. O. Menteş,
• G. Zamborlini,
• A. Sala and
• A. Locatelli

Beilstein J. Nanotechnol. 2014, 5, 1873–1886, doi:10.3762/bjnano.5.198

• different contributions to the LEED spot-profile were observed in real-time as a function of temperature, which resulted in a model of oxygen-induced extended surface defects [73]. Aside structure and magnetism, transformations between different iron-oxide phases were studied by using the SPELEEM methods

Donor–acceptor graphene-based hybrid materials facilitating photo-induced electron-transfer reactions

• Anastasios Stergiou,
• Georgia Pagona and
• Nikos Tagmatarchis

Beilstein J. Nanotechnol. 2014, 5, 1580–1589, doi:10.3762/bjnano.5.170

• fluorescence quenching of the coumarin moiety. However, fluorescence is activated (on) and significantly enhanced inside the cells by glutathione-initiated dissociation. Donor–acceptor hybrids based on exfoliated graphene However, as mentioned earlier, the surface defects in the sp2-network of GO influence the

Probing the electronic transport on the reconstructed Au/Ge(001) surface

• Franciszek Krok,
• Mark R. Kaspers,
• Alexander M. Bernhart,
• Marek Nikiel,
• Benedykt R. Jany,
• Paulina Indyka,
• Mateusz Wojtaszek,
• Rolf Möller and
• Christian A. Bobisch

Beilstein J. Nanotechnol. 2014, 5, 1463–1471, doi:10.3762/bjnano.5.159

• surface transport in Si(111)-√3 × √3:Ag [13] and thin Bi(111) films on silicon [12][16] would be expected. However, the maps of the potential show no fine-structure related to the step edges or other surface defects so we conclude that the main current is not carried by the surface, i.e., the Au atomic

Restructuring of an Ir(210) electrode surface by potential cycling

• Khaled A. Soliman,
• Dieter M. Kolb,
• Ludwig A. Kibler and
• Timo Jacob

Beilstein J. Nanotechnol. 2014, 5, 1349–1356, doi:10.3762/bjnano.5.148

• monoatomic high steps. Rather small flat surface regions appear for CO-cooled Ir(210), as seen in the height profile shown in Figure 2b. The height profile shown in Figure 3b indicates that the density of surface defects is higher for the H2-cooled Ir(210) surface than that for the CO-cooled surface (Figure

• mechanism [19]. So far, we were not able to identify the type of surface defects, which act as active centers for CO oxidation on H2-cooled Ir(210). However, these sites are absent at the CO-cooled Ir(210) surface, which explains the higher overpotential. After applying oxidation–reduction cycles, the peak

Topology assisted self-organization of colloidal nanoparticles: application to 2D large-scale nanomastering

• Hind Kadiri,
• Serguei Kostcheev,
• Daniel Turover,
• Rafael Salas-Montiel,
• Komla Nomenyo,
• Anisha Gokarna and
• Gilles Lerondel

Beilstein J. Nanotechnol. 2014, 5, 1203–1209, doi:10.3762/bjnano.5.132

• small post diameter equivalent to 195 nm, the presence of the dislocation increases, as seen in Figure 4a. These posts appear as surface defects. They increase the dislocation density in the structure. Silicon nanostructures produced by RIE etching The effect of dry etching on the patterned silicon has

Growth and characterization of CNT–TiO₂ heterostructures

• Yucheng Zhang,
• Ivo Utke,
• Johann Michler,
• Gabriele Ilari,
• Marta D. Rossell and
• Rolf Erni

Beilstein J. Nanotechnol. 2014, 5, 946–955, doi:10.3762/bjnano.5.108

• surfaces are also non-reactive and are used to render the ALD process selective in self-assembled monolayer molecules [23]. Only surface defects on CNTs and graphene allow for the chemisorption of metal-organic precursor molecules. Basically, surface functional groups need to be generated on pristine

• such as H3PO4 (together with a chromic acid) and HNO3 triggered conformal growth of ruthenium [26] and SiO2, TiO2, and Al2O3 (after thermal annealing) [27]. Such surface defects seem to be naturally present on multi-wall CNTs with a given surface density. They are responsible for local metal oxide

Optimizing the synthesis of CdS/ZnS core/shell semiconductor nanocrystals for bioimaging applications

• Li-wei Liu,
• Si-yi Hu,
• Ying Pan,
• Jia-qi Zhang,
• Yue-shu Feng and
• Xi-he Zhang

Beilstein J. Nanotechnol. 2014, 5, 919–926, doi:10.3762/bjnano.5.105

• depend on their diameter, the control over the size of the ODs, their size distribution, crystallinity, and surface defects is crucial. Although they have good stability in terms of physics, the application of QDs in biology and cancer detection has been delayed due to their dispersion behaviour in

• QDs, and 38 ns for CdS QDs. ZnS has a major influence on the lifetime decay profile of CdS/ZnS QDs. Trapping states are caused by surface defects located within the bandgap, which lead to the rise of nonradiative recombination. Emission spectra The emission spectra were collected by using a Fluorolog

Pyrite nanoparticles as a Fenton-like reagent for in situ remediation of organic pollutants

• Carolina Gil-Lozano,
• Elisabeth Losa-Adams,
• Alfonso F.-Dávila and
• Luis Gago-Duport

Beilstein J. Nanotechnol. 2014, 5, 855–864, doi:10.3762/bjnano.5.97

• (diameter: 20 nm) with broader crystallinity at the outer interfaces, providing a greater number of surface defects, which is advantageous for generating H2O2. Batch reactions were run to monitor the kinetics of CuPc degradation in real time and the amount of H2O2. A markedly greater degradation of CuPc was

Preparation of poly(N-vinylpyrrolidone)-stabilized ZnO colloid nanoparticles

• Tatyana Gutul,
• Emil Rusu,
• Nadejda Condur,
• Veaceslav Ursaki,
• Evgenii Goncearenco and
• Paulina Vlazan

Beilstein J. Nanotechnol. 2014, 5, 402–406, doi:10.3762/bjnano.5.47

• photoluminescence intensity was increased because of the passivation of surface defects in the nanoparticles [7]. Nanohybrid films with resistivity of 108 Ω·cm were obtained by using PVP with molar mass of 400,000 at various Zn2+/PVP ratios [8]. Colloidal solutions of ZnO are obtained by different methods. For

• indicative of high-quality of ZnO nanoparticles in this sample, i.e., the PPV shell effectively passivates the surface defects of ZnO nanoparticles. The photoluminescence spectra of the components of a colloidal ZnO/PVP/methanol solution are shown in Figure 3. The methanol exhibits a broad luminescence

Manipulation of nanoparticles of different shapes inside a scanning electron microscope

• Boris Polyakov,
• Sergei Vlassov,
• Leonid M. Dorogin,
• Jelena Butikova,
• Mikk Antsov,
• Sven Oras,
• Rünno Lõhmus and
• Ilmar Kink

Beilstein J. Nanotechnol. 2014, 5, 133–140, doi:10.3762/bjnano.5.13

• oscillation direction (Figure S5, Supporting Information File 1) the NPs usually moved forward (motion in the manipulation direction), however, sometimes the NPs randomly deviated from the forward motion and moved aside (Figure 6). Such events are probably caused by surface defects. In summary, a tip

Modulation of defect-mediated energy transfer from ZnO nanoparticles for the photocatalytic degradation of bilirubin

• Tanujjal Bora,
• Karthik K. Lakshman,
• Soumik Sarkar,
• Abhinandan Makhal,
• Samim Sardar,
• Samir K. Pal and
• Joydeep Dutta

Beilstein J. Nanotechnol. 2013, 4, 714–725, doi:10.3762/bjnano.4.81

• (Figure 1b). Following the optical characterization of the ZnO nanoparticle samples, we have explored the effect of the concentration of the surface defects in the ZnO nanoparticles on the photocatalytic degradation of BR, when using the nanoparticles as a photocatalyst medium. The photocatalytic

• . However, in the presence of the ZnO nanoparticles as the catalyst medium, a much faster degradation of BR was observed. In this context, it has been previously shown that the defect-mediated energy transfer from the surface defects of ZnO nanoparticles to the BR molecules through the FRET mechanism is the

• of surface defects. The rates of the photocatalytic degradation of BR were found to follow a first-order exponential equation with a maximum photocatalytic activity for the ZnO nanoparticles annealed at 250 °C. However, when the surface defects were reduced by annealing the ZnO nanoparticles at

Photoresponse from single upright-standing ZnO nanorods explored by photoconductive AFM

• Igor Beinik,
• Markus Kratzer,
• Astrid Wachauer,
• Lin Wang,
• Yuri P. Piryatinski,
• Gerhard Brauer,
• Xin Yi Chen,
• Yuk Fan Hsu,
• Aleksandra B. Djurišić and
• Christian Teichert

Beilstein J. Nanotechnol. 2013, 4, 208–217, doi:10.3762/bjnano.4.21

• . The surface conductivity of ZnO is highly dependent on the presence of adsorbates [20][21][22][23]. Such surface defects serve as binding sites for chemisorption processes and may contribute to the scattering and trapping of carriers [24], which lower the intrinsic conductivity of the material

Reversible mechano-electrochemical writing of metallic nanostructures with the tip of an atomic force microscope

• Christian Obermair,
• Marina Kress,
• Andreas Wagner and
• Thomas Schimmel

Beilstein J. Nanotechnol. 2012, 3, 824–830, doi:10.3762/bjnano.3.92

• tip-induced surface defects are found on the sample surface. Following the same procedure described above for the deposition of the copper structure with the shape of the digit “6”, a new structure with the shape of the digit “9” was deposited after dissolution of the “6”, at exactly the same position

Paper modified with ZnO nanorods – antimicrobial studies

• Mayuree Jaisai,
• Sunandan Baruah and
• Joydeep Dutta

Beilstein J. Nanotechnol. 2012, 3, 684–691, doi:10.3762/bjnano.3.78

• superoxide anions (·O2−), hydrogen peroxide (H2O2), hydroxyl radicals (·OH), hydrogendioxide anion (HO2−), and hydroperoxy radicals (·HO2). Surface area and surface defects play an important role in the photocatalytic activity of metal-oxide nanostructures. One-dimensional nanostructures such as nanorods

Effect of the tip state during qPlus noncontact atomic force microscopy of Si(100) at 5 K: Probing the probe

• Adam Sweetman,
• Sam Jarvis,
• Rosanna Danza and
• Philip Moriarty

Beilstein J. Nanotechnol. 2012, 3, 25–32, doi:10.3762/bjnano.3.3

• -induced imaging variation At 5 K we routinely observe the c(4 × 2) reconstruction and associated surface defects (Figure 1a). Note that in order to avoid perturbation of the surface during scanning we typically image at a setpoint corresponding to low tip–sample interaction (i.e., at a frequency shift

Highly efficient ZnO/Au Schottky barrier dye-sensitized solar cells: Role of gold nanoparticles on the charge-transfer process

• Tanujjal Bora,
• Htet H. Kyaw,
• Soumik Sarkar,
• Samir K. Pal and
• Joydeep Dutta

Beilstein J. Nanotechnol. 2011, 2, 681–690, doi:10.3762/bjnano.2.73

• . However, it has been well documented that gold can form both ohmic as well as Schottky junctions with n-type ZnO, depending on the crystal defects of ZnO [24][25]. In this regard, Brillson and coworkers [26][27] demonstrated that by removing the surface defects of ZnO, a ZnO/Au ohmic junction can be

• converted to a Schottky junction. Therefore, in the present study, in order to ensure the formation of a Schottky barrier at the ZnO/Au interface, the ZnO/Au photoelectrodes were annealed at 450 °C in air for 30 min after the deposition of the Au nanoparticles in order to remove the surface defects of ZnO

Superhydrophobicity in perfection: the outstanding properties of the lotus leaf

• Hans J. Ensikat,
• Petra Ditsche-Kuru,
• Christoph Neinhuis and
• Wilhelm Barthlott

Beilstein J. Nanotechnol. 2011, 2, 152–161, doi:10.3762/bjnano.2.19

• retraction of a drop [13], similar to the measurement shown in Figure 5. Table 1 shows, in addition to other relevant properties, the maximal adhesion forces of water drops on fresh lotus leaves and leaves of other species with intact wax. The adhesion forces are strongly dependent on surface defects which

Enhanced visible light photocatalysis through fast crystallization of zinc oxide nanorods

• Sunandan Baruah,
• Mohammad Abbas Mahmood,
• Myo Tay Zar Myint,
• Tanujjal Bora and
• Joydeep Dutta

Beilstein J. Nanotechnol. 2010, 1, 14–20, doi:10.3762/bjnano.1.3

• surface defects play an important role in the photocatalytic activity of metal-oxide nanostructures, as the contaminant molecules need to be adsorbed on to the photocatalytic surface for the redox reactions to occur. The higher the effective surface area, the higher will be the adsorption of target

• within the band gap (surface defects) [16], thereby affecting the optical and electronic properties [17]. Increased electron trapping due to higher defect sites leads to enhancement in the photocatalytic efficiency. This increase in photocatalytic efficiency is possible provided the electron-hole pair