Modeling and simulation of carbon-nanocomposite-based gas sensors

• Roopa Hegde,
• Punya Prabha V,
• Shipra Upadhyay and
• Krishna S B

Beilstein J. Nanotechnol. 2025, 16, 90–96, doi:10.3762/bjnano.16.9

• nanocomposites, like high surface area, excellent electrical conductivity, and chemical stability, make them ideal candidates for the development of high-performance CO gas sensors. Carbon-nanocomposite gas sensors find their application in detecting pollutants such as nitrogen dioxide (NO2), sulfur dioxide (SO2

• showed high sensitivity towards strong electron-withdrawing molecules for NO2 gas detection [10]. To simulate gas adsorption in COMSOL Multiphysics for a gas sensor, several adsorption models can be employed depending on the physical and chemical behavior of the sensor. Commonly used models include the

Nanoarchitectonics with cetrimonium bromide on metal nanoparticles for linker-free detection of toxic metal ions and catalytic degradation of 4-nitrophenol

• Akash Kumar and
• Raja Gopal Rayavarapu

Beilstein J. Nanotechnol. 2024, 15, 1312–1332, doi:10.3762/bjnano.15.106

Nanostructured lipid carriers containing benznidazole: physicochemical, biopharmaceutical and cellular in vitro studies

• Giuliana Muraca,
• María Esperanza Ruiz,
• Rocío C. Gambaro,
• Sebastián Scioli-Montoto,
• María Laura Sbaraglini,
• Gisel Padula,
• José Sebastián Cisneros,
• Cecilia Yamil Chain,
• Vera A. Álvarez,
• Cristián Huck-Iriart,
• Guillermo R. Castro,
• María Belén Piñero,
• Matias Ildebrando Marchetto,
• Catalina Alba Soto,
• Germán A. Islan and
• Alan Talevi

Beilstein J. Nanotechnol. 2023, 14, 804–818, doi:10.3762/bjnano.14.66

• –H flexion in the amide (1500–1400 cm−1 is also the absorption range of the C=C in the benzyl group), 1357 cm−1 to the symmetric vibration of R–NO2, and 1141 cm−1 to C–N in the imidazole ring [26]. Myristyl myristate displayed peaks at 2913 and 2848 cm−1 corresponding to C–H of alkane, 1731–1184 cm−1

Humidity-dependent electrical performance of CuO nanowire networks studied by electrochemical impedance spectroscopy

• Jelena Kosmaca,
• Juris Katkevics,
• Jana Andzane,
• Raitis Sondors,
• Liga Jasulaneca,
• Raimonds Meija,
• Kiryl Niherysh,
• Yelyzaveta Rublova and
• Donats Erts

Beilstein J. Nanotechnol. 2023, 14, 683–691, doi:10.3762/bjnano.14.54

• sensitive and fast responding nanowire-based gas sensors for the detection of CO, C2H5OH, H2S, and NO2 [10][11][12][13][14]. Unusually strong space-charge-limited currents observed in individual CuO nanowires [15] in combination with the mechanical strength [9][16] motivate their application as durable

Rapid fabrication of MgO@g-C₃N₄ heterojunctions for photocatalytic nitric oxide removal

• Minh-Thuan Pham,
• Duyen P. H. Tran,
• Xuan-Thanh Bui and
• Sheng-Jie You

Beilstein J. Nanotechnol. 2022, 13, 1141–1154, doi:10.3762/bjnano.13.96

• efficiency for NOx, NO, and NO2 [12]. However, these studies only focused on the synthesis of MgO from Mg(NO3)2·6H2O, increasing time and cost of the synthesis process. Commercial MgO as a precursor material for MgO@g-C3N4 heterojunctions has not been studied. Furthermore, there are no relevant reports on

• potassium iodide (KI) for holes (h+). The photocatalytic NO degradation experiments were performed under the previously described conditions. The photocatalytic NO degradation efficiency (η), the yield of NO2 conversion (γ), the apparent quantum efficiency (AQE, φ), and the DeNOx index (αDeNOX αDeNOx) were

• calculated by using Equations 1–4: [41][42][43]: where CNO is the concentration of NO (ppb), CNO2 is the concentration of NO2 (ppb), the index “i” represents the initial concentration, and the index “f” represents the final concentration. NA is the Avogadro constant (mol−1), Vt is the flow rate of NO (L·min

A nonenzymatic reduced graphene oxide-based nanosensor for parathion

• Sarani Sen,
• Anurag Roy,
• Ambarish Sanyal and
• Parukuttyamma Sujatha Devi

Beilstein J. Nanotechnol. 2022, 13, 730–744, doi:10.3762/bjnano.13.65

• potential range from +0.2 to −1.0 V with a scan rate of 100 mV·s−1 and compared with the control group (bare GCE and GO/GCE). It is in good agreement with the literature reports that a sharp cathodic peak (Epc1) at −0.58 V was observed in the first cycle due to the reduction of the nitro group of PT (NO2–PT

• with previous reports [21][23][24]. In this study, we chose the irreversible reduction peak of PT (NO2–PT to NHOH–PT) of the first cycle due to its suitability for important measurements in nanosensor applications. The amount of exfoliated GO dispersed on bare GCE is vital in optimizing the sensing

Modeling a multiple-chain emeraldine gas sensor for NH₃ and NO₂ detection

• Hana Sustkova and
• Jan Voves

Beilstein J. Nanotechnol. 2022, 13, 721–729, doi:10.3762/bjnano.13.64

• good properties for NO2 detection. Keywords: ammonia; gas sensor; nitrogen dioxide; numerical computation; polyaniline; Introduction Polyaniline is a conducting polymer consisting of benzene rings connected by nitrogen units, which can be used in a wide spectrum of applications, for example, dyes for

• it shows a resistance change when gas molecules are in the vicinity of the chain. Interesting for this application could be the detection of NH3 or NO2 [5]. Mechanism of Gas Sensing When gas molecules interact with the PANI chain, the resistance of the bulk material changes. For example, ammonia gas

• resistance [6]. In the work of Kroutil et al. [7], a polyaniline gas sensor setup was used for measuring NH3, NO2, and other gases. Ammonia should be, according to these results, the gas that most affects the polyaniline resistance; nitrogen dioxide moderately affects the resistance. Many electronic and

A chemiresistive sensor array based on polyaniline nanocomposites and machine learning classification

• Jiri Kroutil,
• Alexandr Laposa,
• Ali Ahmad,
• Jan Voves,
• Vojtech Povolny,
• Ladislav Klimsa,
• Marina Davydova and
• Miroslav Husak

Beilstein J. Nanotechnol. 2022, 13, 411–423, doi:10.3762/bjnano.13.34

• 1999/2, 182 21 Prague, Czech Republic 10.3762/bjnano.13.34 Abstract The selective detection of ammonia (NH3), nitrogen dioxide (NO2), carbon oxides (CO2 and CO), acetone ((CH3)2CO), and toluene (C6H5CH3) is investigated by means of a gas sensor array based on polyaniline nanocomposites. The array

• higher sensitivity toward NH3 in comparison to a pristine PANI layer. PANI+ZnO composite shows the lowest sensitivity to all gases. Moreover, the resistance decreases when the polyaniline composite sensing layers are exposed to toluene. In addition, the sensor responses of all sensing layers to NO2 gas

• deformation of the polyaniline conjugation chains. The summary of the gas sensor responses for all active layers is shown in Figure 9. All layers show an increasing resistivity as a clear response to CO, CO2, NH3, and NO2. Additionally, to exclude the influence of humidity on the sensor signal, the sensor

Tin dioxide nanomaterial-based photocatalysts for nitrogen oxide oxidation: a review

• Viet Van Pham,
• Hong-Huy Tran,
• Thao Kim Truong and
• Thi Minh Cao

Beilstein J. Nanotechnol. 2022, 13, 96–113, doi:10.3762/bjnano.13.7

• ppm) for 60 min [2]. Nitrogen oxides (NOx, including NO and NO2) are poisonous and highly reactive gases. Nitrogen dioxide (NO2) is associated with respiratory diseases and mortality. NOx is formed when fuel is burnt at high temperatures and emitted by automobiles, trucks, and various non-road

• warming, and respiratory diseases in humans (Figure 1a). NOx pollution damages lung cells and reacts with molecules in the air when released into the ozone layer. NOx can aggravate respiratory diseases such as asthma, bronchitis, and cardiovascular diseases. When humans are exposed to NO2 at

• concentrations of over 200 µg/m3, even for periods of time, this will cause adverse effects on the respiratory system. Some studies have shown that NO2 concentrations over 500 µg/m3 can cause acute health effects. Although the lowest threshold for NO2 exposure with a direct effect on lung function in asthmatic

Morphology-driven gas sensing by fabricated fractals: A review

• Vishal Kamathe and
• Rupali Nagar

Beilstein J. Nanotechnol. 2021, 12, 1187–1208, doi:10.3762/bjnano.12.88

• , NO2 and SO2 gases at 100 ppm gas at 350 degree centigrade. Though the morphology of the fractals did not change appreciably, Pt doping led to faster response and recovery times. This could be due to the excellent interaction of Pt with hydrogen via the established spillover effect that catalyzes

• geometry. Plugotarenko et al. employed sol–gel method to prepare SiO2·SnOx·CuOy nanofilms from a tetraethoxysilane (TEOS) alcohol solution modified by metal salts and applied the samples for NO2 sensing [50]. The SiO2·SnOx·CuOy films annealed at 500 °C exhibited a sample surface consisting of crater-like

• sample, exhibiting a combination of hillocks and pores, showed the maximum sensitivity (S = 0.29) towards NO2. Another study reported dendritic nanowires (DNWs) of SnO2 on a gold-coated silicon substrate for NO2 sensing [66]. The samples were prepared by evaporation–condensation. Figure 6a and Figure 6b

A review of defect engineering, ion implantation, and nanofabrication using the helium ion microscope

• Frances I. Allen

Beilstein J. Nanotechnol. 2021, 12, 633–664, doi:10.3762/bjnano.12.52

Solution combustion synthesis of a nanometer-scale Co₃O₄ anode material for Li-ion batteries

• Monika Michalska,
• Huajun Xu,
• Qingmin Shan,
• Shiqiang Zhang,
• Yohan Dall'Agnese,
• Yu Gao,
• Amrita Jain and
• Marcin Krajewski

Beilstein J. Nanotechnol. 2021, 12, 424–431, doi:10.3762/bjnano.12.34

• temperatures and leads to the decomposition of the fuel resulting in the formation of gaseous by-products, such as CO2, NO2, or NH3, and the generation of heat. On one hand, this initiates a foaming reaction, on the other hand, this prevents from grain growth and agglomeration processes [10][42][43][45][46][47

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

• –carbon composite (Ni@rGO). Previous work with WO3 had used either NiO (as part of the WO3 lattice), solely carbon, Pd-surface decorated WO3 (Pd@WO3), or Pd or Pt@carbon@WO3. We demonstrate the gas response for pure WO3, rGO/WO3 and Ni@rGO/WO3 sensing elements towards NO2 and acetone in air as well as

• towards CO in N2. The addition of 0.35 wt % Ni@rGO composite to WO3 enables the increase of the sensory response by more than 1.6 times for NO2 vapors. The gas response towards acetone using 0.35 wt % Ni@rGO/WO3 composite was 1.5 times greater for 3500 ppm than for 35,000 ppm acetone. For 0.35 wt % Ni@rGO

• in sensor resistance during exposure to the gas is measured directly [5]. Gases can either be oxidizing, such as NO, N2O, NO2, O3, and Cl2, reducing, such as H2S, NH3, CO, H2, SO2, and CH4, or rather inert, such as CO2 [6][7]. VOCs are organic molecules such as acetone, ethanol, and formaldehyde [8

Gas-sensing features of nanostructured tellurium thin films

• Dumitru Tsiulyanu

Beilstein J. Nanotechnol. 2020, 11, 1010–1018, doi:10.3762/bjnano.11.85

• were interpreted in terms of an increase in disorder (amorphization), leading to an increase in the surface chemical activity of chalcogenides, as well as an increase in the active surface area due to substrate porosity. Keywords: gas-sensing properties; NO2; tellurium thin films; nanocrystalline

• ] started to thoroughly investigate the use of Te thin films as an active element in gas sensor manufacturing. They showed that microcrystalline Te thin films, grown by thermal vacuum evaporation, exhibit high sensitivity to low concentrations (ppm range) of nitrogen dioxide (NO2) even at room temperature

• . Subsequent studies showed that it was possible to increase the concentration range sensitivity to more than 300 ppm NO2 by growing single-crystalline microtubes. In order to do that, Te metal was evaporated onto quartz substrates under an inert argon gas at ambient pressure [7]. Later, it was also found that

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

• , graphene has a unique structure and distinguished properties. Plenty of works are in progress to investigate the applications of graphene or its derivatives in the field of gas sensing [20][21], including room temperature CO2 gas sensors and room temperature double-layer graphene NO2 gas sensors prepared

• ][25][26][27][28]. An optimum ratio of the composition and the fine nanostructure will contribute to obtaining better gas-sensing properties. A gas sensor with 3 wt % reduced graphene oxide (rGO) incorporated into In2O3 showed a rapid response, an improved stability and a low limit of detection of NO2

Chiral nanostructures self-assembled from nitrocinnamic amide amphiphiles: substituent and solvent effects

• Hejin Jiang,
• Huahua Fan,
• Yuqian Jiang,
• Li Zhang and
• Minghua Liu

Beilstein J. Nanotechnol. 2019, 10, 1608–1617, doi:10.3762/bjnano.10.156

• glutamide. We speculate that the substituent position of NO2 might affect the arrangement of molecules in the self-assembly process and subsequently lead to a different packing model of the NCLG compounds. UV–vis and circular dichroism spectra In order to further understand the different self-assembly

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

• OS content (Table S2, Supporting Information File 1) of the 4% MnO2–CuO–Fe2O3/CNTs catalyst is 66.7%, whereas it is 36.8% in Mn–Cu–FeOx/CNTs-IWIM catalyst. OS has a higher mobility than OL, which is in favor of the oxidation of NO to NO2, accelerating the SCR reaction [37]. This was also confirmed by

• by N2 gas. The total flow rate was 700 mL/min equivalent to a weight hourly space velocity (WHSV) of 280 L·gcat−1·h–1. A flue-gas analyzer (Kane International Limited, KM950) equipped with the NO, NO2, SO2, and O2 sensors was used to monitor the gas concentration. All data were recorded after 30 min

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

• to exposure for humans [18]. In environmental monitoring applications, nitrogen dioxide should be detected in the 20 to 200 ppb range. Some authors have reported the detection of NO2 at such low concentrations using sensors employing carbon nanotubes [31][32]. In addition, sensors can be employed as

• concentration was kept constant at 21% throughout the measurement process. The adsorption of oxygen may result in a slight oxidation of the thiols on the long term. The sensors were exposed to different concentrations of nitrogen dioxide (NO2) and ethanol (C2H5OH). The exposure time to gases or vapors was set

• hydrophilic thiols) present higher affinity to H2O than the CH3 groups (in hydrophobic thiols). The response of carbon nanotubes functionalized with short-chain, hydrophilic thiols towards NO2 increases in humid conditions. While at the lower concentrations tested (i.e., 25 to 75 ppm) the response is almost

Site-specific growth of oriented ZnO nanocrystal arrays

• Rekha Bai,
• Dinesh K. Pandya,
• Sujeet Chaudhary,
• Veer Dhaka,
• Vladislav Khayrudinov,
• Jori Lemettinen,
• Christoffer Kauppinen and
• Harri Lipsanen

Beilstein J. Nanotechnol. 2019, 10, 274–280, doi:10.3762/bjnano.10.26

• adsorption of positively (or negatively) charged species. In the present work, only Zn(NO3)3·6H2O is used as precursor to fabricate ZnO crystals and the reaction involved for the formation of ZnO crystals is as follows: As only NO2− ions are released during the reaction, so we can say that the two

• positively charged Zn-terminated polar planes are connected together by adsorption of NO2− and this could understandably account for the attractive force needed between two Zn-terminated basal planes for eventual formation of twinned NCs of ZnO. The growth of c-axis oriented/branched ZnO NCs can be

• formation of coupled branched ZnO NCs. Plausible growth mechanisms underlying the formation of twinned crystals oriented/branched ZnO NCs are presented. The formation of twins seems to be facilitated by the linking of the two positively charged Zn polar surfaces of ZnO NCs by the negatively charged NO2

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

• with iron oxide nanoparticles substantially ameliorated the response towards nitrogen dioxide. Keywords: benzene detection; doping; gas sensor; metal nanoparticle decoration; multiwalled carbon nanotubes; NO2 detection; room temperature gas sensing; surface modification; Introduction Carbon nanotubes

• composites with other materials such as graphene oxide or polyaniline has been reported to detect NO2 [17][18]. The decoration of CNTs with iron oxide has been reported for sensing different species in air such as acetone, CO2 and some volatile organic compounds [19][20][21]. Moreover, composites made of

• CNTs and iron oxide have been also used for sensing ammonia and NOx [22][23]. Among those gases NO2 is considered one of the most dangerous air pollutants occurring both indoors, due to using of gas stoves, and outdoors from fuel powered motor vehicles and power plants especially in long-term exposure

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

• 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

• . The improved experimental schemes are raised and the critical research directions of graphene/metal-oxide sensors in the future are proposed. Keywords: gas sensor; graphene; metal oxide; nitrogen dioxide (NO2); room temperature; Review Introduction Since the discovery by Novoselov and Geim [1

• porous structure and defects for detecting NO2. The sensor showed high sensitivity to NO2 at low concentrations. In another work, Hu et al. [18] fabricated an ultra-sensitive rGO gas sensor, which reached a response of 2.4% to 1 ppb NH3 with an ultra-fast response time of 1.4 s at room temperature. The

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

• [1], security [2][3] as well as for the environment [4][5][6][7][8][9][10][11] in the last few decades. For instance, exposure to low concentrations of CO, CO2, NH3, NO2, CH4 and/or H2S, even in the range of a few parts per million (ppm), can cause suffocation, nervous system disorders, and/or asthma

• annealing and calcination [83]. A very low detection limit (9.7 ppb NOx) with an optimal response time (20 s) is achieved with nanocrystalline (5–10 nm) SnO2 NTs at room temperature [141]. Similar behaviour is exhibited by p-type NiO and CuO toward CO and NO2 [111][112]. The gas sensing behaviour also

• depends on the connectivity of the grains in highly crystalline nanofiber [113][114]. An opposite trend for crystal size is reported by Landau et al. [142] and Choi et al. [111] who obtained a higher response toward CO and NO2 with larger grain fibers. Moreover, the interparticle distance is also a key

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

• observed after the adsorption of other free radical gases such as NO2. The unique change in electronic properties after the adsorption of NO on transition-metal sulfides highlights an effective strategy to distinguish NO from other gas species by experimentally measuring spin-resolved transmission. Our

• they are ultra-sensitive to a number of molecules that are important in environmental studies [18][19][20][21][22][23][24][25][26]. More specifically, it has been suggested that MoS2 exhibits ultrahigh sensitivity to the adsorption of paramagnetic gases such as NO and NO2 [11]. Single-layer MoS2 has

• ]. Besides, the corresponding binding position and energy of NO adsorbed on single-layer MoS2 [23] and WS2 [28] were analyzed from a theoretical point of view. Even though the gas-sensing properties involving NO and NO2 are well studied, few studies [29] have been carried out to explore the difference in

Electrodeposition of reduced graphene oxide with chitosan based on the coordination deposition method

• Mingyang Liu,
• Yanjun Chen,
• Chaoran Qin,
• Zheng Zhang,
• Shuai Ma,
• Xiuru Cai,
• Xueqian Li and
• Yifeng Wang

Beilstein J. Nanotechnol. 2018, 9, 1200–1210, doi:10.3762/bjnano.9.111

• electrochemical detection of glucose, NH3 gas, NO2 gas, ethanol and acetone [40][41][42][43]. Besides, graphene-based sensors have been used to detect phenolic compounds which are aromatic pollutants to the environment and human health [44][45]. These graphene-based sensors exhibit the high detection performance

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

• material for the design of efficient catalytic devices. The NO2 sensing ability of as-deposited ZnO films was investigated with different gas concentrations at an optimized sensing temperature of 120 °C. Surface decoration of plasmonic Au nanoparticles provided an enhanced sensitivity (141 times) with

• 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