Kelvin probe force microscopy work function characterization of transition metal oxide crystals under ongoing reduction and oxidation

• Dominik Wrana,
• Karol Cieślik,
• Wojciech Belza,
• Christian Rodenbücher,
• Krzysztof Szot and
• Franciszek Krok

Beilstein J. Nanotechnol. 2019, 10, 1596–1607, doi:10.3762/bjnano.10.155

• , Germany Peter Grünberg Institute (PGI-7), Forschungszentrum Jülich GmbH, 52425 Jülich, Germany August Chelkowski Institute of Physics, University of Silesia, 40–007 Katowice, Poland 10.3762/bjnano.10.155 Abstract Controlling the work function of transition metal oxides is of key importance with regard to

• method employing KPFM and local conductivity AFM for the characterization of the work function of transition metal oxides may help in understanding the impact of reduction and oxidation on electronic properties, which is of high importance in the development of effective sensing and catalytic devices

• . Keywords: Kelvin probe force microscopy (KPFM); reduction and oxidation; SrTiO3; TiO nanowires; TiO/SrTiO3 heterostructure; transition metal oxides; work function; Introduction Transition metal oxides are viewed today as some of the most promising materials in various fields, ranging from (photo)catalysis

High-temperature resistive gas sensors based on ZnO/SiC nanocomposites

• Vadim B. Platonov,
• Marina N. Rumyantseva,
• Alexander S. Frolov,
• Alexey D. Yapryntsev and
• Alexander M. Gaskov

Beilstein J. Nanotechnol. 2019, 10, 1537–1547, doi:10.3762/bjnano.10.151

• , ultrathin fibers of SiC and metal oxides as well as MO/SiC composites from polymer solutions [16][17][18][19]. The combination of unlimited length, highly porous microstructure, and high surface area come together to create ideal gas sensor materials. In this work, we prepared ZnO/SiC nanocomposite

Selective gas detection using Mn₃O₄/WO₃ composites as a sensing layer

• Yongjiao Sun,
• Zhichao Yu,
• Wenda Wang,
• Pengwei Li,
• Gang Li,
• Wendong Zhang,
• Lin Chen,
• Serge Zhuivkov and
• Jie Hu

Beilstein J. Nanotechnol. 2019, 10, 1423–1433, doi:10.3762/bjnano.10.140

• between the two metal oxides. The sensor based on the Mn3O4/WO3 composite with 3 atom % Mn showed a high selective response to hydrogen sulfide (H2S), ammonia (NH3) and carbon monoxide (CO) at working temperatures of 90 °C, 150 °C and 210 °C, respectively. The demonstrated superior selectivity opens the

Gas sensing properties of individual SnO₂ nanowires and SnO₂ sol–gel nanocomposites

• Alexey V. Shaposhnik,
• Dmitry A. Shaposhnik,
• Sergey Yu. Turishchev,
• Olga A. Chuvenkova,
• Stanislav V. Ryabtsev,
• Alexey A. Vasiliev,
• Xavier Vilanova,
• Francisco Hernandez-Ramirez and
• Joan R. Morante

Beilstein J. Nanotechnol. 2019, 10, 1380–1390, doi:10.3762/bjnano.10.136

• Besòs, Catalonia, Barcelona, 08019, Spain 10.3762/bjnano.10.136 Abstract This work is an investigation of the properties of semiconductor materials based on metal oxides, their catalytic properties, and their application as gas sensors, which were shown to exhibit high sensitivity, stability, and

Photoactive nanoarchitectures based on clays incorporating TiO₂ and ZnO nanoparticles

• Eduardo Ruiz-Hitzky,
• Pilar Aranda,
• Marwa Akkari,
• Nithima Khaorapapong and
• Makoto Ogawa

Beilstein J. Nanotechnol. 2019, 10, 1140–1156, doi:10.3762/bjnano.10.114

• considered the most extensively studied solid among the diverse transition-metal oxides and transition-metal chalcogenides investigated with that focus over the last decades. However, TiO2 has disadvantages such as limited activity together with a reduced sensitivity to sunlight. Hence, alternative

• metal oxides exhibit a large exciton binding energy, large piezoelectric constants and strong photoluminescence. This is of interest not only for applications as photocatalysts but also as sensors, solar cell devices, disinfectants, and cosmetics [137][138]. As discussed above, the dispersion of the

• decrease in the bandgap values by doping with Ag, Pd and other transition metals such as Zr, W, Ce, Sn, Sb and In improve the photoactivity efficiency [140]. Alternatively, combination of TiO2 and ZnO with other metal oxides leads to mixed oxide NPs, including the TiO2–ZnO compositions, which exhibit

Porous N- and S-doped carbon–carbon composite electrodes by soft-templating for redox flow batteries

• Maike Schnucklake,
• László Eifert,
• Jonathan Schneider,
• Roswitha Zeis and
• Christina Roth

Beilstein J. Nanotechnol. 2019, 10, 1131–1139, doi:10.3762/bjnano.10.113

• of the commercial felts (400 °C, up to 30 h) [7]. Also acid treatment [8], electrochemical activation [9], catalytic decoration with metal oxides [10][11], as well as methods to increase the surface area of the felts [12][13] have been reported as possible ways to obtain enhanced activity. Several

Synthesis and characterization of quaternary La(Sr)S–TaS₂ misfit-layered nanotubes

• Marco Serra,
• Erumpukuthickal Ashokkumar Anumol,
• Dalit Stolovas,
• Iddo Pinkas,
• Ernesto Joselevich,
• Reshef Tenne,
• Andrey Enyashin and
• Francis Leonard Deepak

Beilstein J. Nanotechnol. 2019, 10, 1112–1124, doi:10.3762/bjnano.10.111

• , and consequently, the lattice strain. It also appears that beyond an Sr content of ≈60 atom %, the MLC lattice becomes unstable and new modes >680 cm−1 appear, which is typical for metal oxides. DFT calculations of the pristine LaS–TaS2 and the SrxLa1−xS–TaS2 MLC bulk alloys were undertaken. Overall

Glucose-derived carbon materials with tailored properties as electrocatalysts for the oxygen reduction reaction

• Rafael Gomes Morais,
• Natalia Rey-Raap,
• José Luís Figueiredo and
• Manuel Fernando Ribeiro Pereira

Beilstein J. Nanotechnol. 2019, 10, 1089–1102, doi:10.3762/bjnano.10.109

• electrocatalyst used for the reaction. The most commonly used electrocatalyst to supply faster kinetics and a four-electron pathway are platinum-based materials [3][4], which are costly and may assume up to 50% of the total cost of a fuel cell [5]. Transition metals [6][7], metal oxides [8][9] and carbon

The systemic effect of PEG-nGO-induced oxidative stress in vivo in a rodent model

• Qura Tul Ain,
• Samina Hyder Haq,
• Abeer Alshammari,
• Moudhi Abdullah Al-Mutlaq and
• Muhammad Naeem Anjum

Beilstein J. Nanotechnol. 2019, 10, 901–911, doi:10.3762/bjnano.10.91

• made in the synthesis of graphene oxide nanoparticles and their use in medicine, so there is an urgent need to look at the safety and efficacy of these particles in vivo. It has been observed that engineered nanomaterials, e.g., from metals or metal oxides, have the potential to induce toxicity by

Comparing a porphyrin- and a coumarin-based dye adsorbed on NiO(001)

• Sara Freund,
• Antoine Hinaut,
• Nathalie Marinakis,
• Edwin C. Constable,
• Ernst Meyer,
• Catherine E. Housecroft and
• Thilo Glatzel

Beilstein J. Nanotechnol. 2019, 10, 874–881, doi:10.3762/bjnano.10.88

• , Switzerland 10.3762/bjnano.10.88 Abstract Properties of metal oxides, such as optical absorption, can be influenced through the sensitization with molecular species that absorb visible light. Molecular/solid interfaces of this kind are particularly suited for the development and design of emerging hybrid

• semiconductor TiO2 has become one of the most extensively studied metal oxides, especially in the context of scanning probe microscopy (SPM) [1]. The working principle of an n-type DSSC, which is shown in Figure 1a, relies on the functionalization of TiO2 surfaces with dye molecules enabling the absorption of

Synthesis of MnO₂–CuO–Fe₂O₃/CNTs catalysts: low-temperature SCR activity and formation mechanism

• Yanbing Zhang,
• Lihua Liu,
• Yingzan Chen,
• Xianglong Cheng,
• Chengjian Song,
• Mingjie Ding and
• Haipeng Zhao

Beilstein J. Nanotechnol. 2019, 10, 848–855, doi:10.3762/bjnano.10.85

• , only a weak peak of MnO2 (PDF#53-0633) can be observed when the loading was greater than or equal to 4%, whereas no diffraction peaks of metal oxides could be found, suggesting the formation of amorphous metal oxide phases. Amorphous catalytic materials are conducive to SCR activity [19], which is also

• , also verifying the generation of metal oxide catalysts on the CNT surface. The EDX spectrum (Figure 3d) shows signals of Mn, Cu, Fe, O and C. Clear lattice fringes of the metal oxides cannot be observed in the HRTEM images, indicating the generation of amorphous materials, which is consistent with the

Tungsten disulfide-based nanocomposites for photothermal therapy

• Tzuriel Levin,
• Hagit Sade,
• Rina Ben-Shabbat Binyamini,
• Maayan Pour,
• Iftach Nachman and
• Jean-Paul Lellouche

Beilstein J. Nanotechnol. 2019, 10, 811–822, doi:10.3762/bjnano.10.81

• latter group, nanostructures of metals [38], metal oxides (including iron oxides) [39], and metal chalcogenides [40][41] were studied. Tungsten oxides [42] and molybdenum oxides [43] were studied, as well as their disulfides. The disulfides were tested mainly in the forms of nanosheets [44], nanoflakes

A porous 3D-RGO@MWCNT hybrid material as Li–S battery cathode

• Yongguang Zhang,
• Jun Ren,
• Yan Zhao,
• Taizhe Tan,
• Fuxing Yin and
• Yichao Wang

Beilstein J. Nanotechnol. 2019, 10, 514–521, doi:10.3762/bjnano.10.52

• sulfur loading is essential for the practical implementation of Li–S batteries [5][6][7]. To overcome the above-mentioned challenges in Li–S batteries, many strategies have been proposed [8][9][10][11][12]. For example, metal oxides, such as TiO2, ZnO, MnO2, and SiO2, were reported to provide active

• sites for strong S–metal bonding that have been reported to suppress the shuttle effect in polysulfides [13][14][15][16]. Moreover, designing metal oxides into various unique morphologies, e.g., hollow structures, can also provide a physical (or structural) confinement for sulfur [17]. Metal-oxide

• sulfur loading [24][25]. Since sulfur is the major active ingredient in the Li–S cathode, adding more non-sulfur components, such as metal oxides, in the cathode will result in a lower specific capacity. Therefore, the present study will focus on the development of a pure carbon material for the Li–S

Widening of the electroactivity potential range by composite formation – capacitive properties of TiO₂/BiVO₄/PEDOT:PSS electrodes in contact with an aqueous electrolyte

• Konrad Trzciński,
• Mariusz Szkoda,
• Andrzej P. Nowak,
• Marcin Łapiński and
• Anna Lisowska-Oleksiak

Beilstein J. Nanotechnol. 2019, 10, 483–493, doi:10.3762/bjnano.10.49

• charged and discharged over a wide potential range. Both electrical double-layer capacitance and faradaic reactions can contribute to the final capacitance of an electrode. Many different materials have been tested as electrode materials for supercapacitors, such as metal oxides [6][7][8], carbon

Sub-wavelength waveguide properties of 1D and surface-functionalized SnO₂ nanostructures of various morphologies

• Venkataramana Bonu,
• Binaya Kumar Sahu,
• Arindam Das,
• Sankarakumar Amirthapandian,
• Sandip Dhara and
• Harish C. Barshilia

Beilstein J. Nanotechnol. 2019, 10, 379–388, doi:10.3762/bjnano.10.37

• light during the medical process. Among metal oxides, SnO2 NWs, an n-type direct wide-band semiconductor (Eg = 3.6 eV at 300 K), was proved to be excellent sub-wavelength waveguide [3][4][5][6][7][12]. The high refractive index (n = 2.1) of SnO2 allows NWs with an optimal size range (100 to 500 nm) to

• nanoparticles [18] have been reported in our previous studies. We have also deciphered strong correlations of various defects in SnO2 NSs for chemical gas sensing [13] and wettability properties [19]. The growth of metal oxides with controllable dimensions is an important area for technological applications. In

• , which matches closely with our experimental results. Optical properties Waveguide nature SnO2 NBs have been shown to be very good sub-wavelength waveguides among the metal oxides [6][12]. Figure 6 and Figure 7 depict optical images of the single SnO2 NWs demonstrating their waveguide behaviour. Similar

A Ni(OH)₂ nanopetals network for high-performance supercapacitors synthesized by immersing Ni nanofoam in water

• Donghui Zheng,
• Man Li,
• Yongyan Li,
• Chunling Qin,
• Yichao Wang and
• Zhifeng Wang

Beilstein J. Nanotechnol. 2019, 10, 281–293, doi:10.3762/bjnano.10.27

• between active materials and electrolyte, for which transition metal oxides/hydroxides with multiple valence are used as electrode materials [8][9]. EDLCs hold a high power density and long cycling stability, but their practical application is limited by the low energy density. In comparison, pseudo

• -capacitors possess a higher energy density and are regarded as promising candidates for energy storage systems [10]. Among the various transition metal oxides/hydroxides, Ni(OH)2 is an ideal candidate for pseudo-capacitors due to its unique features such as high theoretical capacity and outstanding redox

Thermal control of the defunctionalization of supported Au₂₅(glutathione)₁₈ catalysts for benzyl alcohol oxidation

• Zahraa Shahin,
• Hyewon Ji,
• Rodica Chiriac,
• Nadine Essayem,
• Franck Rataboul and
• Aude Demessence

Beilstein J. Nanotechnol. 2019, 10, 228–237, doi:10.3762/bjnano.10.21

• nanoparticles (GNPs), GNPs have been of great interest in chemistry, dispersed on metal oxides and in CO oxidation reaction [1]. Today, GNPs of diameter less than 10 nm are known to be a remarkable, heterogeneous catalyst, capable of catalyzing a wide range of reactions including hydrocarbon combustion [2

Wet chemistry route for the decoration of carbon nanotubes with iron oxide nanoparticles for gas sensing

• Hussam M. Elnabawy,
• Juan Casanova-Chafer,
• Badawi Anis,
• Mostafa Fedawy,
• Mattia Scardamaglia,
• Carla Bittencourt,
• Ahmed S. G. Khalil,
• Eduard Llobet and
• Xavier Vilanova

Beilstein J. Nanotechnol. 2019, 10, 105–118, doi:10.3762/bjnano.10.10

• into more reactive species that, in turn, interact with CNTs. In addition, such nanoparticles shift the Fermi level of CNTs, adsorb target molecules, and help in mediating the charge transfer between adsorbates and CNTs [6][10]. Several metal oxides have been reported as useful for decorating CNTs and

• improving their interaction with gas molecules. Sensitivity and selectivity can be tailored by selecting the type of metal oxide employed, the size of nanoparticles and the decoration density or loading [6][10][11]. Metal oxides have been extensively investigated for sensing a wide range of gases [12][13

Zn/F-doped tin oxide nanoparticles synthesized by laser pyrolysis: structural and optical properties

• Florian Dumitrache,
• Iuliana P. Morjan,
• Elena Dutu,
• Ion Morjan,
• Claudiu Teodor Fleaca,
• Monica Scarisoreanu,
• Alina Ilie,
• Marius Dumitru,
• Cristian Mihailescu,
• Adriana Smarandache and
• Gabriel Prodan

Beilstein J. Nanotechnol. 2019, 10, 9–21, doi:10.3762/bjnano.10.2

• precursors to oxides (SnO2 and ZnO, in fact Zn-doped SnO2), CO2 and H2O in the laser pyrolysis reaction zone. Due to the much higher reactivity of metals, the metal oxides are formed with priority, and the unoxidized alkyl radicals from the precursors will undergo a complex process involving reactions such

A novel polyhedral oligomeric silsesquioxane-modified layered double hydroxide: preparation, characterization and properties

• Xianwei Zhang,
• Zhongzhu Ma,
• Hong Fan,
• Carla Bittencourt,
• Jintao Wan and
• Philippe Dubois

Beilstein J. Nanotechnol. 2018, 9, 3053–3068, doi:10.3762/bjnano.9.284

• reacts with the metal oxides to form a continuous and compact condensed phase. This mixed carbonized protecting layer provides a good barrier to the transfer of heat and mass, preventing the inner layer against further decomposition and accelerating the formation of char. Evidence in favor of this

Ternary nanocomposites of reduced graphene oxide, polyaniline and hexaniobate: hierarchical architecture and high polaron formation

• Claudio H. B. Silva,
• Maria Iliut,
• Christopher Muryn,
• Christian Berger,
• Zachary Coldrick,
• Vera R. L. Constantino,
• Marcia L. A. Temperini and
• Aravind Vijayaraghavan

Beilstein J. Nanotechnol. 2018, 9, 2936–2946, doi:10.3762/bjnano.9.272

• properties when compared to individual phases or enable new technological applications [1][2][3]. For instance, ternary nanocomposites (conducting polymers, metal oxides and carbon-based materials) exhibit improved energy and power densities, improved stabilities upon charge/discharge cycles [4], and higher

Nanostructure-induced performance degradation of WO₃·nH₂O for energy conversion and storage devices

• Zhenyin Hai,
• Mohammad Karbalaei Akbari,
• Zihan Wei,
• Danfeng Cui,
• Chenyang Xue,
• Hongyan Xu,
• Philippe M. Heynderickx,
• Francis Verpoort and
• Serge Zhuiykov

Beilstein J. Nanotechnol. 2018, 9, 2845–2854, doi:10.3762/bjnano.9.265

• layered transition metal oxides. Keywords: 2D layered oxides; interlayer water; van der Waals interaction; WO3·nH2O; Introduction Within the less than 20 years since the successful exfoliation of atomically thin graphene, 2D layered nanomaterials have been contributing greatly to the advances of

• nanoscience and nanotechnology with their exotic properties and versatility of applications [1][2][3][4][5][6][7][8][9][10]. Among all 2D nanomaterials, 2D transition metal oxides (TMOs) are the group with the highest electrochemical activities for energy conversion and storage [11][12][13][14][15]. As the

Graphene-enhanced metal oxide gas sensors at room temperature: a review

• Dongjin Sun,
• Yifan Luo,
• Marc Debliquy and
• Chao Zhang

Beilstein J. Nanotechnol. 2018, 9, 2832–2844, doi:10.3762/bjnano.9.264

• sensors based on rGO/metal oxides, which exhibit enhanced sensing performance mainly due to the formation of heterojunctions. Tai et al. [46] deposited ZnO nanoparticles and GO thin films on gold interdigital electrodes (IDEs) through a simple spray process and thermally reduced the deposits to ZnO–rGO

• during the carbothermal reduction (1150 °C). Another was the formation of Schottky barriers between ZnO and the metal electrodes, which caused ZnO to exhibit p-type semiconductor properties. The gas-sensing performance parameters of the abovementioned sensors for reducing gases based on metal oxides and

• performance of the ternary composite sensor was still the p–n heterojunctions. The gas-sensing performance parameters of the abovementioned NO2 sensors based on metal oxides and rGO enhanced by the formation of semiconductor interfaces are listed in Table 2. Enhancement by improved morphology and structure By

Improved catalytic combustion of methane using CuO nanobelts with predominantly (001) surfaces

• Qingquan Kong,
• Yichun Yin,
• Bing Xue,
• Yonggang Jin,
• Wei Feng,
• Zhi-Gang Chen,
• Shi Su and
• Chenghua Sun

Beilstein J. Nanotechnol. 2018, 9, 2526–2532, doi:10.3762/bjnano.9.235

• most metal oxides. To improve the reactivity of metal oxides, surfaces with high energy (and thus low surface area), namely minority surfaces, may offer new opportunities. Although minority surfaces often diminish quickly during crystal growth due to their low stability, they can be stabilized by

Thickness-dependent photoelectrochemical properties of a semitransparent Co₃O₄ photocathode

• Malkeshkumar Patel and
• Joondong Kim

Beilstein J. Nanotechnol. 2018, 9, 2432–2442, doi:10.3762/bjnano.9.228

• -dependent properties; Introduction Hydrogen production using water splitting in photoelectrochemical (PEC) cells may help to overcome challenges in the conversion and storage of solar energy. Most of the metal oxides are earth-abundant, non-toxic, stable and easy to synthesise, and hence attractive

• -absorber materials such as metal sulfides and metal oxides via heterojunction. The photocurrent can be further improved by three approaches: The first one is to improve the optoelectronic processes in the Co3O4 film [39], the second is to improve the composition of the heterojunction, i.e. Co3O4/Ga2O3 [42