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

• semiconductors (MOS) are widely used as materials for gas sensing. Usually, MOS gas sensors have some common shortages, such as relatively poor selectivity and high operating temperature. Graphene has drawn much attention as a gas sensing material in recent years because it can even work at room temperature

• , which reduces power consumption. However, the low sensitivity and long recovery time of the graphene-based sensors limit its further development. The combination of metal-oxide semiconductors and graphene may significantly improve the sensing performance, especially the selectivity and response/recovery

• more than 30 min according to World Health Organization [44]. Therefore, there is an urgent need for gas sensors with low cost, outstanding selectivity and sensitivity for detecting these toxic gases [6]. Compared with MOS sensors, graphene/metal-oxide sensors enhance the gas-sensing performance in

Enhancement of X-ray emission from nanocolloidal gold suspensions under double-pulse excitation

• Wei-Hung Hsu,
• Frances Camille P. Masim,
• Armandas Balčytis,
• Hsin-Hui Huang,
• Tetsu Yonezawa,
• Aleksandr A. Kuchmizhak,
• Saulius Juodkazis and
• Koji Hatanaka

Beilstein J. Nanotechnol. 2018, 9, 2609–2617, doi:10.3762/bjnano.9.242

• selectivity based on surface plasmon resonance [15]. An increase of the laser-absorption efficiency can be expected in plasmonic nanoparticles, which results in the efficient generation of highly ionized charge states [13][14]. It is expected that this characteristic interaction between intense femtosecond

Nanocellulose: Recent advances and its prospects in environmental remediation

• Katrina Pui Yee Shak,
• Yean Ling Pang and
• Shee Keat Mah

Beilstein J. Nanotechnol. 2018, 9, 2479–2498, doi:10.3762/bjnano.9.232

• −), phosphate (PO43−), fluoride (F−), and sulphate (SO42−). Cationic CNFs exhibited higher selectivity towards multivalent ions (PO43− and SO42−) than monovalent ions (F− and NO3−). On the other hand, the development of nanocellulose composites as adsorbents with numerous supportive properties, magnetic

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

• , which are prominent in the 440–350 nm region. This feature is useful for a porous Co3O4 material as a semitransparent electrode in water-splitting PEC cells. Moreover, two distinct transitions (positive slope) around 1.5 and 2.4 eV in Figure 2b have different α values, providing optical selectivity that

ZnO-nanostructure-based electrochemical sensor: Effect of nanostructure morphology on the sensing of heavy metal ions

• Marina Krasovska,
• Vjaceslavs Gerbreders,
• Irena Mihailova,
• Andrejs Ogurcovs,
• Eriks Sledevskis,
• Andrejs Gerbreders and
• Pavels Sarajevs

Beilstein J. Nanotechnol. 2018, 9, 2421–2431, doi:10.3762/bjnano.9.227

• nanostructures are promising candidates for use in sensors, especially in electrochemical sensors and biosensors, due to their unique physical and chemical properties, as well as sensitivity and selectivity to several types of contamination, including heavy metal ions. In this work, using the hydrothermal method

• , which limits the flow of liquid around the sample and reduces the probability of grown particles to enter covered areas, providing the necessary selectivity of nanostructure growth only on the electrodes. In the second step a temporary extra rubber sealing mask was applied and Cr electrodes were coated

Block copolymers for designing nanostructured porous coatings

• Roberto Nisticò

Beilstein J. Nanotechnol. 2018, 9, 2332–2344, doi:10.3762/bjnano.9.218

• an immensely attractive (and multidisciplinary) field of research [13][14][15][16][17][18][19][20]. In particular, nanoscopic-ordered porous architectures in the form of thin films have received great attention in the field of membrane science and micro/nanofluidics, due to the high selectivity

• nanoparticles (produced by using PS-b-PEO block copolymers as templates) are deposited via spin-coating onto a macroporous silicon-based substrate, forming a depth-filtering system (i.e., interparticle voids of 15–200 nm). In order to evaluate the selectivity of this porous membrane, two cationic (macro

• )molecules were selected as target probes: methylene blue (a dye of 0.5 nm in width) and the protein RNAse (3.8 nm), respectively. The results evidenced that the diffusion of the protein is more restricted as compared to the dye, suggesting a steric selectivity of the depth-filtering system analyzed. In

Dumbbell gold nanoparticle dimer antennas with advanced optical properties

• Janning F. Herrmann and
• Christiane Höppener

Beilstein J. Nanotechnol. 2018, 9, 2188–2197, doi:10.3762/bjnano.9.205

• particular mastering the formation of sub-nanometer gap sizes requires short, rigid molecules with high chemical selectivity. In addition, these linker molecules should not affect the optical response of the formed antenna. Although sub-nanometer gap dimers can be also formed artificially by the placement of

Electrospun one-dimensional nanostructures: a new horizon for gas sensing materials

• Muhammad Imran,
• Nunzio Motta and
• Mahnaz Shafiei

Beilstein J. Nanotechnol. 2018, 9, 2128–2170, doi:10.3762/bjnano.9.202

• followed by death. Gas sensors are the primary devices used for the detection and monitoring of these pollutants. Employing nanotechnology in sensor applications has significantly improved the performance of such devices, providing enhanced sensitivity, selectivity, low power consumption and high

• discriminate between many different gases in the presence of other gases within low concentration ranges between a few parts per million (ppm) to parts per billion (ppb). The performance parameters of these gas sensors, including sensitivity, selectivity, response and recovery time, stability, reproducibility

• of pure MOx NFs [86]. SnO2 is a widely-used metal oxide material for gas sensing applications because of its low cost and high chemical stability. However, wide application of SnO2-based gas sensors is limited by low sensitivity, slow response, lack of selectivity and the effects of aging. SnO2 NFs

Metal-free catalysis based on nitrogen-doped carbon nanomaterials: a photoelectron spectroscopy point of view

• Mattia Scardamaglia and
• Carla Bittencourt

Beilstein J. Nanotechnol. 2018, 9, 2015–2031, doi:10.3762/bjnano.9.191

• temperatures up to 950 °C the amount of pure substitutional nitrogen (graphitic) and the DOS increase (Figure 3). As mentioned, the low-energy electronic excitation and the selectivity for oxygen dissociation strongly depend on the type of nitrogen dopant present in the sample, as we will discuss in the next

• influenced by the substrate that supports the graphene sample. Both the morphology (moiré pattern) and the electronic interaction play a role in the selectivity of preferential N sites [92][99]. The amount of nitrogen is also an important parameter to preserve the stability and the electronic properties of

Synthesis of a MnO₂/Fe₃O₄/diatomite nanocomposite as an efficient heterogeneous Fenton-like catalyst for methylene blue degradation

• Zishun Li,
• Xuekun Tang,
• Kun Liu,
• Jing Huang,
• Yueyang Xu,
• Qian Peng and
• Minlin Ao

Beilstein J. Nanotechnol. 2018, 9, 1940–1950, doi:10.3762/bjnano.9.185

• heterogeneous Fenton-like system of MnO2-peroxymonosulfate (MnO2-PMS) is proposed. As alternatives to H2O2 and hydroxyl radicals (•OH), peroxymonosulfate (PMS) and the sulfate radical (•SO4−) exhibit a wider functional pH range, convenience in storage and higher oxidation selectivity. Also, compared to iron

The inhibition effect of water on the purification of natural gas with nanoporous graphene membranes

• Krzysztof Nieszporek,
• Tomasz Pańczyk and
• Jolanta Nieszporek

Beilstein J. Nanotechnol. 2018, 9, 1906–1916, doi:10.3762/bjnano.9.182

• graphene. The membrane separation process involves CH4 + N2 mixtures with and without the addition of water. The results show that water is able to form hydrogen bonds with nitrogen atoms located in a nanopore rim. This effect causes a decrease of separation selectivity as well as a reduction of gas

• functionalized graphene membranes can be very sensitive to the presence of water. The increase of the number of highly electronegative atoms such as nitrogen in the nanopore rim creates the opportunity to form hydrogen bridges with mixture components and then influences their selectivity of separation. Moreover

SO₂ gas adsorption on carbon nanomaterials: a comparative study

• Deepu J. Babu,
• Divya Puthusseri,
• Frank G. Kühl,
• Sherif Okeil,
• Michael Bruns,
• Manfred Hampe and
• Jörg J. Schneider

Beilstein J. Nanotechnol. 2018, 9, 1782–1792, doi:10.3762/bjnano.9.169

• adsorption behavior, adsorption isotherms are recorded under pure SO2 atmosphere. The possibility to obtain pure SO2 gas equilibrium adsorption data under these experimental conditions is of great significance for theoretical adsorption investigations and gas mixture selectivity studies. For all the

Free-radical gases on two-dimensional transition-metal disulfides (XS₂, X = Mo/W): robust half-metallicity for efficient nitrogen oxide sensors

• Chunmei Zhang,
• Yalong Jiao,
• Fengxian Ma,
• Sri Kasi Matta,
• Steven Bottle and
• Aijun Du

Beilstein J. Nanotechnol. 2018, 9, 1641–1646, doi:10.3762/bjnano.9.156

• to enable NO2/2D WS2 system display half-metallicity. In an attempt to address the selectivity towards NO gas in moist environments, we have carried out some new calculations on the adsorption of NOx (x = 1, 2) on the WS2 monolayer in the presence of a water molecule. The structures and spin

Cr(VI) remediation from aqueous environment through modified-TiO₂-mediated photocatalytic reduction

• Rashmi Acharya,
• Brundabana Naik and
• Kulamani Parida

Beilstein J. Nanotechnol. 2018, 9, 1448–1470, doi:10.3762/bjnano.9.137

• combined with TiO2 for enhanced photocatalytic reduction of Cr(VI). A one-dimensional CdS–TiO2 core–shell (CdS@TiO2) nano-photocatalyst possessed higher reduction and selectivity of Cr(VI) due to the core–shell structure where hVB+ are trapped by the TiO2 shell [198]. Ultrathin TiO2-coated CdS core–shell

Preparation and morphology-dependent wettability of porous alumina membranes

• Dmitry L. Shimanovich,
• Alla I. Vorobjova,
• Daria I. Tishkevich,
• Alex V. Trukhanov,
• Maxim V. Zdorovets and
• Artem L. Kozlovskiy

Beilstein J. Nanotechnol. 2018, 9, 1423–1436, doi:10.3762/bjnano.9.135

• ]. Membranes with a high selectivity and ordered structure can also be used to separate components of gas and liquid mixtures and to clean them from impurities (filtration). It is believed that in order to increase the selectivity and productivity, the membrane must have a regular structure of near

Colorimetric detection of Cu²⁺ based on the formation of peptide–copper complexes on silver nanoparticle surfaces

• Gajanan Sampatrao Ghodake,
• Surendra Krishna Shinde,
• Rijuta Ganesh Saratale,
• Avinash Ashok Kadam,
• Ganesh Dattatraya Saratale,
• Asad Syed,
• Fuad Ameen and
• Dae-Young Kim

Beilstein J. Nanotechnol. 2018, 9, 1414–1422, doi:10.3762/bjnano.9.134

• . Although colorimetric probes based on the aggregation of nanoparticles (NPs) induced by target-metal ions are advantageous, these probes may have difficulties in detecting Cu2+ in complex matrices [7]. Quantum-dot-based fluorescent probes showed improved sensitivity and selectivity for Cu2+ compared to

• traditional organic probes [8][9][10], but the preparation of such functionalized quantum dots is a time-consuming process. Similarly, colorimetric methods based on Cu2+-dependent click chemistry are well-known for high selectivity and tolerance to interference caused by other metal ions. Nonetheless, these

• and at 1458 cm−1, respectively, in agreement with [23]. Selectivity At first, the selectivity of the functionalized AgNPs was examined with various ions, including Cu2+, Mn2+, Mo3+, Na+, Cr3+, Hg2+, Ni2+, Ca2+, K+, Cs+, Li+, As+, PO43−, NH4, and NO3−, at 100 ppb. The color change of the AgNPs

Nanoporous silicon nitride-based membranes of controlled pore size, shape and areal density: Fabrication as well as electrophoretic and molecular filtering characterization

• Axel Seidenstücker,
• Stefan Beirle,
• Fabian Enderle,
• Paul Ziemann,
• Othmar Marti and
• Alfred Plettl

Beilstein J. Nanotechnol. 2018, 9, 1390–1398, doi:10.3762/bjnano.9.131

• schematically in Figure 1d. The Cr film thickness is determined by the etch selectivity of mask and membrane materials. All the Cr caps on top of the pillars must be clearly separated from the Cr layer on the SiN bottom for the chosen aspect ratio of the pillars. The second part of the mask inversion process

• ]. Selectivity and molecular cut-off depend strongly on pore size and the narrowness of its distribution. Studies of the molecular filtering properties were conducted by real-time fluorescence microscopy. Thus, the diffusion of fluorescent molecules or fluorescent-labeled macromolecules could be observed time

Heterostuctures of 4-(chloromethyl)phenyltrichlorosilane and 5,10,15,20-tetra(4-pyridyl)-21H,23H-porphine prepared on Si(111) using particle lithography: Nanoscale characterization of the main steps of nanopatterning

• Phillip C. Chambers and
• Jayne C. Garno

Beilstein J. Nanotechnol. 2018, 9, 1211–1219, doi:10.3762/bjnano.9.112

• was chosen to passivate the silicon surface and to serve as a resist layer to accomplish spatial selectivity for surface reactions. The uncovered sites of Si(111) within the nanoholes expose hydroxyl groups for binding organosilanes such as CMPS. Preparation of CMPS nanodots The samples with nanoholes

• exposed nanoholes of Si(111). Spatial confinement facilitated the growth of CMPS layers in the vertical direction, which was produced by cross-linking to form intramolecular siloxane bonds. Spatial selectivity for the preparation of heterostructures of CMPS and H2TPyP Heterostructures of CMPS-porphyrin

• reaction, nanodots of CMPS were produced. (d) Reaction with porphyrin produced taller heterostructures with spatial selectivity for the sites of CMPS nanodots. Nanoholes within a thin film of OTS. (a) Topography frame, 3 × 3 µm2; and simultaneously acquired (b) phase image. (c) Zoom-in topograph of

Understanding the performance and mechanism of Mg-containing oxides as support catalysts in the thermal dry reforming of methane

• Nor Fazila Khairudin,
• Mohd Farid Fahmi Sukri,
• Mehrnoush Khavarian and
• Abdul Rahman Mohamed

Beilstein J. Nanotechnol. 2018, 9, 1162–1183, doi:10.3762/bjnano.9.108

• support and active metal particles [16][17][18]. The loss of catalytic activity or selectivity over time of production affects the cost of catalyst replacement, process shutdown, and product quality and quantity. Numerous researchers have reported that noble metal-based catalysts, such as Pt, Rh, Pd, Ru

• conducted by numerous researchers to assist in the reaction for decreasing carbon formation and to improve catalyst activity, selectivity, and stability. To date, an incorporated mechanism for carbon deposition and removal has yet to be proposed and is still being debated among researchers. The present

• determining the activity and the selectivity of the catalysts are the dispersion and the physico-chemical characteristics of active metals on the support catalyst. Three general approaches are applied for the catalyst preparation, including (i) deposition of active metals onto a support; (ii) precipitation of

Enzymatically promoted release of organic molecules linked to magnetic nanoparticles

• Chiara Lambruschini,
• Silvia Villa,
• Luca Banfi,
• Fabio Canepa,
• Fabio Morana,
• Annalisa Relini,
• Paola Riani,
• Renata Riva and
• Fulvio Silvetti

Beilstein J. Nanotechnol. 2018, 9, 986–999, doi:10.3762/bjnano.9.92

• delivery; enzyme catalysis; magnetic nanoparticles; magnetic properties; peptides; Introduction A major challenge of current cancer therapies is to improve the selectivity of chemotherapeutic agents against tumour cells. This goal may be achieved by exploiting smart drug delivery approaches. Magnetic

• cancer cells. To achieve selectivity, there are two main strategies. In the first one, the enzyme is exogenous and is artificially introduced into the body and selectively targeted to the tumour tissue using genes, viruses or antibodies (GDEPT, VDEPT, and ADEPT, respectively). Alternatively, the enzyme

• delivering an exogenous enzyme to the desired site. Both the use of magnetic nanoparticles and the DEPT approach have the limitation that complete selectivity is not possible in the release of the active chemotherapeutic agent. For example, an unspecific release of the drug from the nanoparticles may take

Comparative study of antibacterial properties of polystyrene films with TiO_x and Cu nanoparticles fabricated using cluster beam technique

• Vladimir N. Popok,
• Cesarino M. Jeppesen,
• Peter Fojan,
• Anna Kuzminova,
• Jan Hanuš and
• Ondřej Kylián

Beilstein J. Nanotechnol. 2018, 9, 861–869, doi:10.3762/bjnano.9.80

• through mechanisms based on (i) metal ion selectivity (replacement of original metals leading to cellular dysfunction); (ii) metal reduction potential (generating or catalysing the formation of reactive oxygen species (ROS) damaging cellular proteins, lipids and DNA) and (iii) direct nanoparticle (NP

Noble metal-modified titania with visible-light activity for the decomposition of microorganisms

• Maya Endo,
• Zhishun Wei,
• Kunlei Wang,
• Baris Karabiyik,
• Kenta Yoshiiri,
• Paulina Rokicka,
• Bunsho Ohtani,
• Agata Markowska-Szczupak and
• Ewa Kowalska

Beilstein J. Nanotechnol. 2018, 9, 829–841, doi:10.3762/bjnano.9.77

• have already been used for various antimicrobial applications, such as (i) ionization techniques, (ii) membrane technologies to reduce biofouling of sanitation devices, (iii) development of sensors with high sensitivity and selectivity for pathogen detection, (iv) everyday products (cosmetics, shoes

Surface-plasmon-enhanced ultraviolet emission of Au-decorated ZnO structures for gas sensing and photocatalytic devices

• T. Anh Thu Do,
• Truong Giang Ho,
• Thu Hoai Bui,
• Quang Ngan Pham,
• Hong Thai Giang,
• Thi Thu Do,
• Duc Van Nguyen and
• Dai Lam Tran

Beilstein J. Nanotechnol. 2018, 9, 771–779, doi:10.3762/bjnano.9.70

• and reasonably fast response/recovery time were reported for a gas sensor based on Au-decorated ZnO structures. The highest selectivity towards NO2 was compared to other combustion gases such as CO, and C3H8. In addition, the photocatalytic decomposition of organic dyes under sunlight using PL

• dynamic response transients of both sensors to varying concentrations (15–60 ppm) of n-propane at an operating temperature about of 120 °C were also investigated (Figure S1b,c, Supporting Information File 1). These improvements of the sensitivity and the selectivity allow for the detection of a specific

Heavy-metal detectors based on modified ferrite nanoparticles

• Urszula Klekotka,
• Ewelina Wińska,
• Elżbieta Zambrzycka-Szelewa,
• Dariusz Satuła and
• Beata Kalska-Szostko

Beilstein J. Nanotechnol. 2018, 9, 762–770, doi:10.3762/bjnano.9.69

• and phthalic anhydride for the detection of Pb in water and food products was described in the literature [15]. The role of the selected inorganic core, however, was not discussed. The modified nanoparticles used in this study had a selectivity for Pb ions twice of that for other metals. In this paper

A review of carbon-based and non-carbon-based catalyst supports for the selective catalytic reduction of nitric oxide

• Shahreen Binti Izwan Anthonysamy,
• Syahidah Binti Afandi,
• Mehrnoush Khavarian and
• Abdul Rahman Bin Mohamed

Beilstein J. Nanotechnol. 2018, 9, 740–761, doi:10.3762/bjnano.9.68

• discharge, electrochemical cell, radiation, and the wet system are examples of the dry technique while the scrubber is an example of the wet technique [3]. Of these technologies, due to its effectiveness, low cost, and high selectivity, the SCR of NO has emerged as the most promising method and has been

• oxidation of SO2 to SO3, so that high activity and selectivity, high thermal stability, and a temperature lower than 300 °C can be achieved, thus increasing the lifetime of the catalyst. Lower-temperature SCR is foremost in importance to ensure the complete removal of NO. This is because of the wide

• -exchange zeolite catalysts [15]. The Mn-based catalyst is one of the most active metal oxide catalysts for high N2 selectivity at low temperature and is recognised by many researchers as a potential alternative for the common catalyst. Jin et al. [16] successfully used a Mn-based catalyst with the addition