Transition from freestanding SnO₂ nanowires to laterally aligned nanowires with a simulation-based experimental design

• Jasmin-Clara Bürger,
• Sebastian Gutsch and
• Margit Zacharias

Beilstein J. Nanotechnol. 2020, 11, 843–853, doi:10.3762/bjnano.11.69

• result, Choi et al. were able to measure an improved sensitivity for gas sensors made of tin oxide nanowires (SnO2 NWs) in comparison with powder-based SnO2 thin films [9]. For the use of NWs in electronic and sensor devices, freestanding NWs often have to be scratched off of the growth substrate

Exfoliation in a low boiling point solvent and electrochemical applications of MoO₃

• Matangi Sricharan,
• Bikesh Gupta,
• Sreejesh Moolayadukkam and
• H. S. S. Ramakrishna Matte

Beilstein J. Nanotechnol. 2020, 11, 662–670, doi:10.3762/bjnano.11.52

• layered materials, molybdenum oxide (MoO3) has gained special attention because of its numerous applications in electronics, catalysis, electrochemistry, solar cells and gas sensors [6]. Monolayered and few-layered MoO3 has been reported to have better properties than the bulk material [7]. Thus, it is

Synthesis and acetone sensing properties of ZnFe₂O₄/rGO gas sensors

• Kaidi Wu,
• Yifan Luo,
• Ying Li and
• Chao Zhang

Beilstein J. Nanotechnol. 2019, 10, 2516–2526, doi:10.3762/bjnano.10.242

• , it may be possible to diagnose diabetes using a nondestructive testing technology based on sensing acetone. Thus, it is necessary to develop novel micro/nanomaterials, which can be applied as high-performance gas sensors to detect acetone at low concentration or to monitor variations of its

• concentration. Due to their excellent properties and cost efficiency, gas sensors based on metal oxide semiconductors, such as ZnO [5], SnO2 [6], WO3 [7], TiO2 [8], Er-SnO2 [9], Au-In2O3 [10], GO-WO3 [11] and Ni-SnO2/G [12] have been widely studied until now. However, their sensing properties regarding low

• effects in the heterostructures. This will enable corresponding gas sensors to accurately detect and monitor acetone vapor in real-time. In this view, compounding with certain organic or inorganic material could improve the gas sensing properties of ZnFe2O4 [18][19]. As a novel 2D carbon-based material

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

• prevention of indoor exposure to harmful aromatic VOCs, a new application has arisen recently for the development of such gas sensors. In fact, recent scientific evidence has shown a correlation between the presence of some VOCs in exhaled human breath and the presence of disease. For instance, the presence

• correlated to the active sensing film/material used. Various nanomaterial-based gas sensors have been investigated to monitor the presence of aromatic VOCs. The ones mainly studied are based on metal oxides, carbon nanotubes, graphene and hybrid materials [5][6]. Carbon nanotube based gas sensors (e.g

• they are strong covalent (chemisorption) or weak (physisorption), highly impact the sensor performance, that is, the sensitivity, response and recovery time, and detection range. Unlike metal-oxide-based gas sensors, CNT-based sensors operate at room temperature (low activation energy) and can

Review of advanced sensor devices employing nanoarchitectonics concepts

• Katsuhiko Ariga,
• Tatsuyuki Makita,
• Masato Ito,
• Taizo Mori,
• Shun Watanabe and
• Jun Takeya

Beilstein J. Nanotechnol. 2019, 10, 2014–2030, doi:10.3762/bjnano.10.198

• that the delicate modulation of nanoarchitectures can improve chemical sensor capabilities. As an example of nanoarchitectonics effects between multiple components in sensing materials, Chen, Shi, and co-workers demonstrated highly sensitive resistance-based NOx gas sensors incorporating a dispersed

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

• abundant adsorbates, also mimicking the typical operating temperatures of metal oxide gas sensors [51]. Numerical calculations suggest that H2O and CO2 species present in air saturate almost all free adsorption sites on TiO2-terminated SrTiO3(100) [52]. The low Redhead desorption temperature of H2O (CO2

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

• high temperatures in the range of 300–800 °C. The development of high-temperature gas sensors requires the creation of new materials that are stable under these conditions. The stability of nanostructured semiconductor oxides at high temperature can be enhanced by creating composites with highly

• –800 °C. The composition of the main components of exhaust gas includes CO2, CO, SO2, H2S, NOx, CnH2n+2, and NH3. The ratio of these components depends primarily on the technology features and fuel type. High-temperature gas sensors are needed for local monitoring of pollution emissions, as well as for

• monitoring the complete combustion of fuel and controlling medium-temperature chemical and metallurgical processes [3][4][5]. The development of high-temperature gas sensors requires the creation of new materials that are stable at 300–600 °C, high humidity, and lack of oxygen. Nanostructured semiconductor

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

• . Gas sensing through resistance change caused by the oxidation of combustible gases on the surface is one of the major applications of WO3. However, the response mechanism of WO3 makes selective gas detection difficult. For WO3-based gas sensors, the working temperature is a key factor that can

• to enhance the selectivity of WO3-based gas sensors. Previous studies found that the gas sensing response of pure phase WO3 is usually low and improving this response for a particular gas could simultaneously enhance their selectivity [7][8][9]. Kabcum et al. developed a sensor based on PdO

• -nanoparticle-decorated WO3 nanorods, where 1 wt % Pd-WO3 showed excellent selectivity to H2 (>1000 times) over other gases and WO3 shows almost no selectivity [10]. Choi et al. fabricated gas sensors based on pristine WO3 nanorods and Cr2O3-functionalized WO3 nanorods. The gas sensing results showed that 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

• sensor response due to the unlikelihood of sample recrystallization. The results from the ammonia detection experiments showed that the ratio of the sensor response to the surface area exhibits similar values for both the individual nanowire and nanopowders-based sensor materials. Keywords: gas sensors

• surface-to-volume ratio of gas sensing materials an important parameter in determining their gas sensitivity. Traditionally, quasi-0-dimensional (i.e., spherical) nano-objects have been used in order to create highly porous materials. In gas sensors, agglomerates of nanoparticles with a high specific area

Imaging the surface potential at the steps on the rutile TiO₂(110) surface by Kelvin probe force microscopy

• Masato Miyazaki,
• Huan Fei Wen,
• Quanzhen Zhang,
• Yuuki Adachi,
• Jan Brndiar,
• Ivan Štich,
• Yan Jun Li and
• Yasuhiro Sugawara

Beilstein J. Nanotechnol. 2019, 10, 1228–1236, doi:10.3762/bjnano.10.122

• steps in the catalytic reaction. Keywords: catalyst; Kelvin probe force microscopy; Smoluchowski effect; step; titanium dioxide; Introduction Titanium dioxide (TiO2) has attracted considerable interest for its promising applications as a photocatalyst and as catalyst support, as well as in gas sensors

A carrier velocity model for electrical detection of gas molecules

• Ali Hosseingholi Pourasl,
• Sharifah Hafizah Syed Ariffin,
• Mohammad Taghi Ahmadi,
• Razali Ismail and
• Niayesh Gharaei

Beilstein J. Nanotechnol. 2019, 10, 644–653, doi:10.3762/bjnano.10.64

• . Graphene nanoribbons (GNRs) which have exceptional electrical, physical, and chemical properties can fulfil all of these requirements. The detection of gas molecules using gas sensors, particularly in medical diagnostics and safety applications, is receiving particularly high demand. GNRs exhibit

• detection approaches have been studied, and their electrical properties have also been investigated [5][6][7][8][9]. In addition, many researchers have experimentally worked on the fabrication of graphene and GNR-based biosensors and gas sensors [10][11][12][13][14][15]. Most of the previous works are

• ) [29], the carrier concentration including the gas adsorption effect can be formulated for AGNR-FET-based gas sensors. where kB is the Boltzmann constant and T is the temperature. We now have all the information required to calculate the carrier velocity. Finally, based on Equation 7, the carrier

Hydrophilicity and carbon chain length effects on the gas sensing properties of chemoresistive, self-assembled monolayer carbon nanotube sensors

• Juan Casanova-Cháfer,
• Carla Bittencourt and
• Eduard Llobet

Beilstein J. Nanotechnol. 2019, 10, 565–577, doi:10.3762/bjnano.10.58

• response and selectivity. This would make the detection of polar and nonpolar gas species employing low-power gas sensors easier, even under fluctuating ambient moisture conditions. Keywords: carbon length chain; gas sensing mechanism; hydrophilicity; hydrophobicity; multiwall carbon nanotubes (MWCNTs

• ); self-assembled monolayer (SAM); thiol; Introduction Carbon nanotubes were first observed by Sumio Iijima in 1991 [1] and since then, this nanostructure has been widely used in chemoresistive gas sensors [2][3][4][5] due to the possibility to engineer its sensitivity towards chemicals present in a

• , pristine carbon nanotubes (CNTs) present some limitations for gas sensing. For example, carbon nanotube gas sensors often suffer from slow recovery, especially when operated at room temperature, which eventually results in baseline and response drift. For that reason, it is usually necessary to heat up the

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

• Ti/TiO2:H/BiVO4:H electrode material could be further covered by conducting polymer prepared via electrodeposition. Beside many possible applications of conducting polymers like hole-transport material [63], electrochromic layers [64], electrochemical sensors [65] and gas sensors [66], a conducting

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

• chemical environment [2][3][4][5]. CNT gas sensors often exhibit fair sensitivity to gases even when operated at room temperature. Since their electrical conductivity is affected upon the adsorption of gases, their response is often measured as a change in resistance of a CNT film. The fact that CNT gas

• chemical composition of the iron oxide decorated carbon nanotube samples were investigated employing transmission electron microscopy (TEM), Raman spectroscopy and X-ray photoelectron spectroscopy (XPS). The differently decorated CNT samples were used to make gas sensors for detecting nitrogen dioxide. A

• s in a continuous scanning mode. Fabrication and testing of gas sensors In order to check the effect of the different decorations on the gas sensing properties of modified CNTs, simple sensing devices were fabricated. For that purpose, small rectangular pieces of a silicon wafer, previously oxidized

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

• rate at room temperature. In this review, we have summarized the latest progress of graphene/metal-oxide gas sensors for the detection of NO2, NH3, CO and some volatile organic compounds (VOCs) at room temperature. Meanwhile, the sensing performance and sensing mechanism of the sensors are discussed

• ], graphene has been widely used in various fields such as photocatalysts, lithium battery electrodes, supercapacitors, gas sensors and electronic devices [2][3][4] due to its high specific surface area (2630 m2/g) and high carrier mobility at room temperature [5]. The electrical properties of graphene are

Oriented zinc oxide nanorods: A novel saturable absorber for lasers in the near-infrared

• Pavel Loiko,
• Tanujjal Bora,
• Josep Maria Serres,
• Haohai Yu,
• Magdalena Aguiló,
• Francesc Díaz,
• Uwe Griebner,
• Valentin Petrov,
• Xavier Mateos and
• Joydeep Dutta

Beilstein J. Nanotechnol. 2018, 9, 2730–2740, doi:10.3762/bjnano.9.255

• epitaxy, metal-organic chemical vapor deposition, pulsed laser deposition), or by wet-chemical processes (e.g., the hydrothermal method, electrochemical deposition) [4]. The hydrothermal growth of ZnO NRs is a relatively simple, versatile and low temperature process [5]. ZnO NRs are used in gas sensors

• excellent sensing properties of the ZnO NRs, such composite structures can be of interest for the development of bio-molecule and gas sensors based on pulsed waveguide lasers. Experimental Growth of ZnO NRs ZnO NRs were directly grown on microscope glass slides (thickness: 1 mm, double-side polished) using

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

• in everyday life. Herein, we review recent developments of gas sensors based on electrospun 1D nanostructures in different sensing platforms, including optical, conductometric and acoustic resonators. After explaining the principle of electrospinning, we classify sensors based on the type of

• benefits and limitations for every approach. Keywords: 1D nanostructures; conductometric devices; electrospinning; gas sensors; optical sensors; resonators; Review 1 Introduction The monitoring and control of air pollutants, toxic gases and explosives has become increasingly important for human wellness

• 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

Synthesis of hafnium nanoparticles and hafnium nanoparticle films by gas condensation and energetic deposition

• Irini Michelakaki,
• Nikos Boukos,
• Dimitrios A. Dragatogiannis,
• Spyros Stathopoulos,
• Costas A. Charitidis and
• Dimitris Tsoukalas

Beilstein J. Nanotechnol. 2018, 9, 1868–1880, doi:10.3762/bjnano.9.179

• the sensitivity of gas sensors [12], twinned silver NPs show important different chemical activity compared to their single crystalline counterparts [13]. These and many other examples illustrate that investigating the morphology and structure of metal NPs is essential for their efficient utilization

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

• ], composites of nanoflower-like CuxO and multilayer graphene (CuMGCs) [5] have been successfully synthesized as new types of room-temperature NO gas sensors. Compared with 3D materials [6], two-dimensional (2D) materials (sheets with thickness of on atom) [7][8][9][10][11][12][13][14][15] such as graphene [8

• ][16], phosphorene [9], siligraphene (SiC5) [10] and molybdenum disulfide (MoS2) [11][17] possess a high specific surface area and high electrical conductivity making them the ideal candidates for gas sensors. In particular, investigations of XS2-based (X = Mo, W) monolayer nanodevices demonstrate that

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

• . Keywords: Au-decorated ZnO; carrier dynamics; gas sensors; photocatalyst; SPR effect; Introduction Inorganic transition metal oxide sensor devices have attracted attention in particular for improving gas sensing, energy conversion, electronics, photocatalysis and optoelectronic devices [1][2][3][4]. Among

• them, ZnO nanostructures have particularly attracted attention for use in gas sensors due to their stability and relatively high sensitivity to target gases such as NO2, NO, CO, n-propane (C3H8), and NH3. In general, gas sensing devices based on ZnO structures are evidenced to be influenced by many

• and support the design of efficient NO2 gas sensing and photocatalysis devices. The effects of Au NPs on the performance of ZnO-based gas sensors were also investigated at an optimized operating temperature of 120 °C towards pollutant gases in a wide range of concentrations. The enhanced sensitivity

Synthesis and characterization of two new TiO₂-containing benzothiazole-based imine composites for organic device applications

• Anna Różycka,
• Agnieszka Iwan,
• Krzysztof Artur Bogdanowicz,
• Michal Filapek,
• Natalia Górska,
• Damian Pociecha,
• Marek Malinowski,
• Patryk Fryń,
• Agnieszka Hreniak,
• Jakub Rysz,
• Paweł Dąbczyński and
• Monika Marzec

Beilstein J. Nanotechnol. 2018, 9, 721–739, doi:10.3762/bjnano.9.67

• dioxide, due to its suitable band position, non-toxicity, low cost, and simple synthesis, is an appropriate material for modification of various metals. Its chemical stability and biocompatibility plays an important role in various applications such as gas sensors, photocatalytic hydrogen generation

Sensing behavior of flower-shaped MoS₂ nanoflakes: case study with methanol and xylene

• Maryam Barzegar,
• Masoud Berahman and
• Azam Iraji zad

Beilstein J. Nanotechnol. 2018, 9, 608–615, doi:10.3762/bjnano.9.57

• scanning electron microscopy (FE-SEM, TE-SCAN, MIRA3). The Brunauer–Emmett–Teller (BET) surface area of the products was analyzed using a Micromeritics nitrogen adsorption apparatus. Fabrication of gas sensors An alumina wafer with an area of 1 cm2 was considered as the proper substrate for our gas sensors

Anchoring Fe₃O₄ nanoparticles in a reduced graphene oxide aerogel matrix via polydopamine coating

• Błażej Scheibe,
• Radosław Mrówczyński,
• Natalia Michalak,
• Karol Załęski,
• Michał Matczak,
• Mateusz Kempiński,
• Zuzanna Pietralik,
• Mikołaj Lewandowski,
• Stefan Jurga and
• Feliks Stobiecki

Beilstein J. Nanotechnol. 2018, 9, 591–601, doi:10.3762/bjnano.9.55

• batteries [8][9][10][11], supercapacitors [12][13][14][15][16]), sensors (gas sensors [17][18][19], biosensors [20][21]) and adsorbers (oil pollution [22][23], organic contaminants [24][25]). Moreover, the properties of GO-based aerogels can be modified by addition of various functional additives, e.g

• ][34], gas sensors [18] or even nanoswitches/actuators [22]. The magnetic properties of hybrid aerogels are related to the presence of magnetic nanoparticles (MNPs) which can be in ferromagnetic or superparamagnetic state and are embedded in aerogel matrix. Iron oxide nanoparticles, such as magnetite

Gas-sensing behaviour of ZnO/diamond nanostructures

• Marina Davydova,
• Alexandr Laposa,
• Jiri Smarhak,
• Alexander Kromka,
• Neda Neykova,
• Josef Nahlik,
• Jiri Kroutil,
• Jan Drahokoupil and
• Jan Voves

Beilstein J. Nanotechnol. 2018, 9, 22–29, doi:10.3762/bjnano.9.4

• : density functional theory (DFT); gas sensor; interdigital electrodes; nanocrystalline diamond; sensitivity; zinc oxide (ZnO); Introduction Currently, a number of studies have been focused on developing gas sensors based on nanomaterials and/or nanostructures. Metal oxides are the most common sensing

• materials and a variety of studies have been carried out to improve the response of these gas sensors [1][2][3][4]. In particular, ZnO nanorods with n-type semiconducting behaviour and large surface-to-volume ratio have attracted great interest due to their wide range of application possibilities in solar

• cell electrodes, light emitting devices, quantum dots and gas sensors [5][6][7][8][9][10][11][12][13]. The improvement in response of metal-oxide sensors has been observed by several authors, due to the formation of isolated functional layers on the one-dimensional nanostructure surface using metal

Fluorination of vertically aligned carbon nanotubes: from CF₄ plasma chemistry to surface functionalization

• Claudia Struzzi,
• Mattia Scardamaglia,
• Jean-François Colomer,
• Alberto Verdini,
• Luca Floreano,
• Rony Snyders and
• Carla Bittencourt

Beilstein J. Nanotechnol. 2017, 8, 1723–1733, doi:10.3762/bjnano.8.173

• makes the surface highly hydrophobic: the introduction of polar groups has been successfully adopted to initiate subsequent functionalization [22] and to profitably implement the fluorinated carbon nanomaterials in numerous applications, including gas sensors for hindering the moisture interference [23