Nanomaterials for photocatalysis and applications in environmental remediation and renewable energy

• Viet Van Pham and
• Wee-Jun Ong

Beilstein J. Nanotechnol. 2023, 14, 722–724, doi:10.3762/bjnano.14.58

• fuels generates harmful emissions to the environment, such as carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), nitric oxide and nitrogen dioxide (together termed NOx), and fluorinated gases (e.g., hydrofluorocarbons, perfluorocarbons, and sulfur hexafluoride) which are currently considered

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

• -equilibrium Green’s functions formalism. The numerical results are compared with experimental data of ammonia and nitrogen dioxide detection. Multiple molecules of PANI in the form of emeraldine salt were studied with more than one absorbed molecule of ammonia or nitrogen dioxide. From the I–V characteristics

• 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

• 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

• between VOCs, supported by a vector machine to distinguish between acetone, nitrogen dioxide, and ammonia, and by a neutral network model to distinguish between ammonia and formaldehyde gas [7][8][9]. In our previous work [10], we demonstrated a combination of organic (polyaniline, PANI) and inorganic

• dioxide, nitrogen dioxide, carbon monoxide, acetone, and toluene). Moreover, the obtained data were used for machine learning classification. Many pattern recognition models based on intuitive, linear and nonlinear supervised techniques have been explored in E-nose data [11][12]. A considerable number of

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

• the COVID-19 pandemic in the past year. WHO also reported that the emissions of nitrogen oxides in the early 1980s over the world were estimated at approximately 150 × 1012 g/year while the concentration of nitrogen dioxide outdoor can achieve up to 940 µg/m3 (0.5 ppm) for 30 min and 400 µg/m3 (0.21

• 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

Silver nanoparticles nucleated in NaOH-treated halloysite: a potential antimicrobial material

• Yuri B. Matos,
• Rodrigo S. Romanus,
• Mattheus Torquato,
• Edgar H. de Souza,
• Rodrigo L. Villanova,
• Marlene Soares and
• Emilson R. Viana

Beilstein J. Nanotechnol. 2021, 12, 798–807, doi:10.3762/bjnano.12.63

• are oxygen and nitrogen dioxide (both gaseous substances) from the reaction 2AgNO3→2Ag(s) + O2 + 2NO2(g) [36], we expect to see a mass reduction as AgNP nucleates. Also, because the nucleation is an endothermic process, we expect to see endothermic peaks. Table 2 divides the results into five

Gas-sensing features of nanostructured tellurium thin films

• Dumitru Tsiulyanu

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

• different operating temperatures with respect to scanning electron microscopy and X-ray diffraction analyses. It was shown that both types of films interacted with nitrogen dioxide, which resulted in a decrease of electrical conductivity. The gas sensitivity, as well as the response and recovery times

• ] 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

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

• were most responsive to nitrogen dioxide and ethanol vapors, even in the presence of ambient humidity. In particular, this nanomaterial was about eight times more sensitive to nitrogen dioxide than bare Au-decorated carbon nanotubes when operated at room temperature. This response enhancement is

• candidates for integration into different types of transducers such as chemoresistors, resonant gravimetric or field effect devices, only to cite a few applications. Bare carbon nanotubes have been employed to detect gases such as nitrogen dioxide [7], ammonia [8], oxygen [9] or ethanol [10]. However

• semiconducting character before being integrated in gas sensing devices. In view of developing sensitive, fast-responding, low power consumption and more selective sensors towards nitrogen dioxide or ethanol, in this paper, we combine oxygen plasma treated, Au-decorated MWCNTs with different thiols (see Figure

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

• 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

• electrical resistance against time. Nitrogen dioxide was found to strongly interact with carbon nanotube sensors, and as a result, the sensors did not fully recover their baseline resistance value during the cleaning phase, which was conducted at room temperature without heating. Applying mild heating or UV

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

• . 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

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

• remarkable semiconducting properties [20][21]. For instance, hydrogen-terminated NCD films exhibit changes in their surface conductivity in the presence of phosgene and could be utilized as an integrator-type gas sensor [22][23]. Up to now, many research groups have focused on nitrogen dioxide (NO2) sensing

• . For instance, a hydrogen-terminated nanocone array exhibited a fast response time (4.7 s) towards 10 ppm of NO2 at 150 °C [13]. On the other hand, a room-temperature-operated gas sensor based on H-terminated diamond films showed a long response time and recovery time towards nitrogen dioxide [24

• ) in order to investigate their gas sensing properties for nitrogen dioxide (NO2), ammonia (NH3) and carbon dioxide (CO2) at different concentration ranges of 25–100 ppm or 1250–5000 ppm. For this purpose we developed three different gas sensor devices based on i) NCD thin films, ii) ZnO nanorods, and

Metal oxide nanostructures: preparation, characterization and functional applications as chemical sensors

• Dario Zappa,
• Angela Bertuna,
• Elisabetta Comini,
• Navpreet Kaur,
• Nicola Poli,
• Veronica Sberveglieri and
• Giorgio Sberveglieri

Beilstein J. Nanotechnol. 2017, 8, 1205–1217, doi:10.3762/bjnano.8.122

• . Surface morphologies and crystal structures were investigated through scanning electron microscopy and Raman spectroscopy. Furthermore, different batches of sensors have been prepared, and their sensing performances towards carbon monoxide and nitrogen dioxide have been explored. Moreover, metal oxide

• , up to now we do not have enough information to determine which parameter has the biggest impact on the sensor response. Concerning nitrogen dioxide instead, NiO is very sensitive, more than all other materials. The optimal working temperature of NiO is 200 °C, with a response of about 6 to 1 ppm of

• respect to chemical sensing. Different batches of sensors have been prepared, and their sensing performances towards carbon monoxide and nitrogen dioxide have been explored. The results show that the best-performing materials for detecting CO are WO3 and SnO2, while NiO performs much better than other

Study of the correlation between sensing performance and surface morphology of inkjet-printed aqueous graphene-based chemiresistors for NO₂ detection

• F. Villani,
• C. Schiattarella,
• T. Polichetti,
• R. Di Capua,
• F. Loffredo,
• B. Alfano,
• M. L. Miglietta,
• E. Massera,
• L. Verdoliva and
• G. Di Francia

Beilstein J. Nanotechnol. 2017, 8, 1023–1031, doi:10.3762/bjnano.8.103

• , low-cost process that meets the requests coming from the increasing field of paper-based electronics and paving the way towards a flexible, green-by-design mass production. Keywords: aqueous graphene dispersion; gas sensors; inkjet printing; liquid phase exfoliation; nitrogen dioxide; paper-based

CVD transfer-free graphene for sensing applications

• Chiara Schiattarella,
• Sten Vollebregt,
• Tiziana Polichetti,
• Brigida Alfano,
• Ettore Massera,
• Maria Lucia Miglietta,
• Girolamo Di Francia and
• Pasqualina Maria Sarro

Beilstein J. Nanotechnol. 2017, 8, 1015–1022, doi:10.3762/bjnano.8.102

• straightforward integration in electronic devices. Keywords: ammonia; chemiresistors; CMOS-compatible process; graphene; nitrogen dioxide; transfer-free growth; Introduction Due to its extraordinary electronic, chemical, mechanical, thermal and optical properties, graphene has been defined as the “wonder

Graphene functionalised by laser-ablated V₂O₅ for a highly sensitive NH₃ sensor

• Margus Kodu,
• Artjom Berholts,
• Tauno Kahro,
• Mati Kook,
• Peeter Ritslaid,
• Helina Seemen,
• Tea Avarmaa,
• Harry Alles and
• Raivo Jaaniso

Beilstein J. Nanotechnol. 2017, 8, 571–578, doi:10.3762/bjnano.8.61

• monolayer per laser pulse are the advantages worth mentioning. The method of PLD has recently been applied to improve the nitrogen dioxide (NO2) sensing properties of chemical vapour deposition (CVD) grown, single-layer graphene in our previous work, using ZrO2 and Ag for functionalisation [14]. In the

• structures was investigated using Raman spectroscopy. Based on the electrical conductivity modulation, the room temperature gas sensing properties of the manufactured sensor structure towards ammonia (NH3) and (for comparison) nitrogen dioxide (NO2) gases were investigated. Results Figure 1a shows a typical

Impact of air exposure and annealing on the chemical and electronic properties of the surface of SnO₂ nanolayers deposited by rheotaxial growth and vacuum oxidation

• Monika Kwoka and
• Maciej Krzywiecki

Beilstein J. Nanotechnol. 2017, 8, 514–521, doi:10.3762/bjnano.8.55

• very sensitive SnO2 thin films [13][14][15][16] that yield the highest sensor response to nitrogen dioxide [17]. Our current approach is focused on the rheotaxial growth of Sn single nanolayers under ultrahigh-vacuum conditions combined with the simultaneous in situ vacuum oxidation (RGVO), which

Sensitive detection of hydrocarbon gases using electrochemically Pd-modified ZnO chemiresistors

• Elena Dilonardo,
• Michele Penza,
• Marco Alvisi,
• Gennaro Cassano,
• Cinzia Di Franco,
• Francesco Palmisano,
• Luisa Torsi and
• Nicola Cioffi

Beilstein J. Nanotechnol. 2017, 8, 82–90, doi:10.3762/bjnano.8.9

• Equation 1. Thus, the sensitivity towards HC gases can be improved by Pd NP catalysts deposited onto ZnO NR surface. To evaluate the sensor selectivity, the mean sensitivity of pristine and Pd-modified ZnO NRs towards nitrogen dioxide and butane, at an operating temperature of 300 °C, is reported in Figure

Nanostructured TiO₂-based gas sensors with enhanced sensitivity to reducing gases

• Wojciech Maziarz,
• Anna Kusior and
• Anita Trenczek-Zajac

Beilstein J. Nanotechnol. 2016, 7, 1718–1726, doi:10.3762/bjnano.7.164

• -made mass flow and humidity controllers. The sensors were exposed to the following gases: acetone (CO(CH3)2, up to 8 ppm), nitric oxides (NOx, up to 400 ppm), hydrogen (H2, up to 2000 ppm), ozone (O3, made by a custom UV generator, up to 500 ppb), and nitrogen dioxide (NO2, up to 100 ppm). Additionally

Enhanced detection of nitrogen dioxide via combined heating and pulsed UV operation of indium oxide nano-octahedra

• Oriol Gonzalez,
• Sergio Roso,
• Xavier Vilanova and
• Eduard Llobet

Beilstein J. Nanotechnol. 2016, 7, 1507–1518, doi:10.3762/bjnano.7.144

• the use of combined heating and pulsed UV light activation of indium oxide gas sensors for enhancing their performance in the detection of nitrogen dioxide in air. Indium oxide nano-octahedra were synthesized at high temperature (900 °C) via vapour-phase transport and screen-printed onto alumina

• current signal), results in an up to 80-fold enhancement in sensitivity to nitrogen dioxide. Furthermore, this combined operation method allows for making savings in power consumption that range from 35% to over 80%. These results are achieved by exploiting the dynamics of sensor response under pulsed UV

• light, which convey important information for the quantitative analysis of nitrogen dioxide. Keywords: dynamic gas sensing; indium oxide; nitrogen dioxide; pulsed UV light; UV-activated metal oxide; Introduction Technological barriers related to sensor performance and power consumption are currently

Pt- and Pd-decorated MWCNTs for vapour and gas detection at room temperature

• Hamdi Baccar,
• Atef Thamri,
• Pierrick Clément,
• Eduard Llobet and
• Adnane Abdelghani

Beilstein J. Nanotechnol. 2015, 6, 919–927, doi:10.3762/bjnano.6.95

• known to weakly interact with VOCs in general and with aromatic VOCs in particular. Therefore, a functionalisation of the carbon nanotube sidewalls is essential to promote sensitivity. In previous works, we used oxygen-plasma-treated multiwalled carbon nanotubes for detecting nitrogen dioxide, ammonia

• application of this concept by producing platinum-decorated carbon nanotubes by means of a wet-chemistry technique [27]. Star et al. electroplated carbon nanotubes with gold, rhodium, palladium or platinum to obtain metal-decorated nanotubes as gas sensors for carbon monoxide, nitrogen dioxide, methane

• multiwalled carbon nanotubes decorated with Au, Pd or Ni nanoparticles (formed by evaporation of metals) and also with Rh or Pt nanoparticles (from a colloidal solution) for detecting benzene, nitrogen dioxide and hydrogen sulphide [34][35][36]. Although the detection could be performed at room temperature

Highly NO₂ sensitive caesium doped graphene oxide conductometric sensors

• Carlo Piloto,
• Marco Notarianni,
• Mahnaz Shafiei,
• Elena Taran,
• Dilini Galpaya,
• Cheng Yan and
• Nunzio Motta

Beilstein J. Nanotechnol. 2014, 5, 1073–1081, doi:10.3762/bjnano.5.120

• ; graphene oxide; highly sensitive; nitrogen dioxide; Introduction Graphene is a single layer of carbon atoms arranged in a honeycomb lattice [1][2]. Intrinsic low noise structure, large specific surface area and extraordinary mobility of carriers are the unique properties that make graphene-based materials

Gas sensing with gold-decorated vertically aligned carbon nanotubes

• Prasantha R. Mudimela,
• Mattia Scardamaglia,
• Oriol González-León,
• Nicolas Reckinger,
• Rony Snyders,
• Eduard Llobet,
• Carla Bittencourt and
• Jean-François Colomer

Beilstein J. Nanotechnol. 2014, 5, 910–918, doi:10.3762/bjnano.5.104

• decorated with gold nanoparticles were investigated as gas sensitive materials for detecting nitrogen dioxide (NO2) at room temperature. Gold nanoparticles of about 6 nm in diameter were sputtered on the top surface of the carbon nanotube forests to enhance the sensitivity to the pollutant gas. We showed

• that the sensing response to nitrogen dioxide depends on the nanotube length. The optimum was found to be 300 µm for getting the higher response. When the background humidity level was changed from dry to 50% relative humidity, an increase in the response to NO2 was observed for all the sensors

• increasing impact in our environment of human activities. The detection of typical pollutants such as nitrogen dioxide (NO2) generated by industrial combustions or by car emissions is critical because of both environmental problems and health consequences for humans. In the last few years, new technologies

Functionalised zinc oxide nanowire gas sensors: Enhanced NO₂ gas sensor response by chemical modification of nanowire surfaces

• Eric R. Waclawik,
• Jin Chang,
• Andrea Ponzoni,
• Isabella Concina,
• Dario Zappa,
• Elisabetta Comini,
• Nunzio Motta,
• Guido Faglia and
• Giorgio Sberveglieri

Beilstein J. Nanotechnol. 2012, 3, 368–377, doi:10.3762/bjnano.3.43

• (THMA) and dodecanethiol (DT), was studied. The response towards ammonia, nitrous oxide and nitrogen dioxide was investigated for three sensor configurations, namely pure ZnO nanowires, organic-coated ZnO nanowires and ZnO nanowires covered with a sparse layer of organic-coated ZnO nanoparticles

• on the gas response. We investigated the chemiresistor response towards ammonia, nitrous oxide and nitrogen dioxide. Results and Discussion The morphology, surface roughness and evenness-of-coating of the ZnO nanowire sensors were examined by scanning electron microscopy. SEM images of each sensor

• and nitrogen oxide. The sensors were maintained at the operating temperature of 190 °C in dry air until a stable sensor resistivity was reached, then the sensors were each exposed, in turn, to ammonia, nitrogen dioxide and nitrous oxide. The gas response results for the pure ZnO nanowire samples, and