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

• composed of PEDOT:PSS/poly(p-anisidine) (PPA) to detect CO was investigated at room temperature. The gas-sensing characteristics of the developed sensors such as sensitivity, response, and recovery time were evaluated at room temperature for different CO concentrations [5]. Many research works on PEDOT:PSS

Insect attachment on waxy plant surfaces: the effect of pad contamination by different waxes

• Elena V. Gorb and
• Stanislav N. Gorb

Beilstein J. Nanotechnol. 2024, 15, 385–395, doi:10.3762/bjnano.15.35

• diminished the further attachment ability of C. fastuosa beetles, but the recovery time was relatively short [7]. Also, three other waxy plant surfaces studied here evoked a significant difference between the results of the first gl1 and the second gl2 experiments on glass, however, concerning only one of

A visible-light photodetector based on heterojunctions between CuO nanoparticles and ZnO nanorods

• Doan Nhat Giang,
• Nhat Minh Nguyen,
• Duc Anh Ngo,
• Thanh Trang Tran,
• Le Thai Duy,
• Cong Khanh Tran,
• Thi Thanh Van Tran,
• Phan Phuong Ha La and
• Vinh Quang Dang

Beilstein J. Nanotechnol. 2023, 14, 1018–1027, doi:10.3762/bjnano.14.84

• . The response time is defined as the time to approach 63% of the maximum recorded photocurrent, while the recovery time is the time to decay to 37% of the highest value of the photodetector [46]. Under the 395 nm light illumination, response time and recovery time are estimated at about 21.38 s and

• maximum values of R, G, and D were 1.38 A·W−1, 4.33, and 2.58 × 1011 Jones, respectively. The recovery time was 84.64 s, while the response time was about 21.38 s to achieve 63% of the maximum photocurrent value. Simultaneously, the CuO NPs/ZnO NRs photodetector shows photoresponse to other visible

Ultrafast signatures of magnetic inhomogeneity in Pd_1−xFe_x (x ≤ 0.08) epitaxial thin films

• Andrey V. Petrov,
• Sergey I. Nikitin,
• Lenar R. Tagirov,
• Amir I. Gumarov,
• Igor V. Yanilkin and
• Roman V. Yusupov

Beilstein J. Nanotechnol. 2022, 13, 836–844, doi:10.3762/bjnano.13.74

• 3.8 and 6.2 atom %, the minimum is ≈10 ps, and for a film with 8 atom % of iron, it is ≈20 ps. However, on warming of a sample, the slow demagnetization time increases and becomes several times longer on approaching the Curie temperature. The magnetization recovery time reveals a similar behavior

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

• to be possessing better gas sensing capabilities. Fab-fracs with these salient features will help in designing the commercial gas sensors with better performance. Keywords: adsorption sites; fabricated fractal; fractal dimension; gas sensor; morphology; pore network; recovery time; response time

• responds in a particular environment with time), the response time (time taken by a sensor to detect no gas to 90% of the gas when exposed to a gas environment), and recovery time (time taken by a sensor to fall to 10% of its baseline resistance value when the gas is removed from the environment

• performed by Kante et al. were in the temperature range of 200–300 °C. For CO, the response was observed to be about 2.5 at 250 °C with a response time of 70 s and a recovery time of 30 s. When exposed to ethanol vapor, the resulting film exhibited a higher sensitivity (400% at 227 °C) towards ethanol with

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

• /WO3 composite and CO gas, a response time (Tres) of 7 min and a recovery time (Trec) of 2 min was determined. Keywords: gas sensing; magnetic measurements; nickel nanoparticles; reduced graphene oxide; tungsten oxide; Introduction Toxic gases as well as volatile organic compounds (VOC) are known air

• high response to gas molecules at room temperature [30]. A disadvantage of rGO gas sensors is the long recovery time because of the high binding force between gas molecules and the graphene material [31]. rGO is a p-type semiconductor and can be used for gas sensing of low concentrations of NO2 at room

• (Figure S1 in Supporting Information File 1). It was found that a constant baseline resistance was observed before and after exposure. The response time (Tres) is 7 min. The recovery time (Trec) is 2 min. A sensor response of the Ni@rGO/WO3 composite of Rair/Rgas = 6.20 in 3500 ppm acetone was detected

Gas-sensing features of nanostructured tellurium thin films

• Dumitru Tsiulyanu

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

• (such as temperature, type and concentration of the target gas), their sensing characteristics were found to vary. For instance, the best response and recovery time values toward NO2 were around 30 s and 7 min, respectively, at 40% sensitivity (defined as the relative variation of the resistance). Such

• hydrothermal recrystallization [23]. The response time range of NH3 gas sensors based on such nanocomponents was 5–18 s but the recovery time ranged between 170–720 s. From comparison with state-of-the-art devices, it can be observed that the physically nanostructured Te thin films exhibit great potential for

• current (in %/ppm) according to Equation 1: where Ia and Ig are the currents flowing through the specimen in air and in the presence of NO2, respectively, and C is the gas concentration. Figure 4 shows that, independent of the operating temperature, the recovery time (trv) is longer than the response time

Nanosecond resistive switching in Ag/AgI/PtIr nanojunctions

• Botond Sánta,
• Dániel Molnár,
• Patrick Haiber,
• Agnes Gubicza,
• Edit Szilágyi,
• Zsolt Zolnai,
• András Halbritter and
• Miklós Csontos

Beilstein J. Nanotechnol. 2020, 11, 92–100, doi:10.3762/bjnano.11.9

• recovery time of the pulse generators after their avalanche breakdown. In order to determine the resistance of the memristive junction between the switching pulses, a DC voltage offset can be applied to the junction via the DC bias terminal of G1. Taking into account the 50 Ω input impedances of the

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

• the substance (g), P is the purity of the liquid and ρ is the density of the liquid (g/cm3). In addition, the response of the sensors was defined as S = Ra/Rg, where Ra and Rg are the resistance values of the sensors in air and in test gas, respectively. The response/recovery time is defined as the

• shorter response/recovery time to 10 ppm acetone at 200 °C. The response time has been measured as 60 s for the pure ZnFe2O4 sensor and only 23 s for the 0.5 wt % ZnFe2O4/rGO sensor. Figure 9 shows the responses of the pure ZnFe2O4 sensor and the 0.5 wt % ZnFe2O4/rGO sensor to acetone at different

• pure ZnFe2O4 and the four ZnFe2O4/rGO gas sensors to (a) 0.8–10 ppm and (b) 25–100 ppm acetone at 200 °C. (c, d) The short term stability and the response/recovery time of the pure ZnFe2O4 and the 0.5 wt % ZnFe2O4/rGO sensors to 10 ppm acetone measured in three cycles. Linear response of (a) the hollow

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

• 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

• therefore lead to the development of commercially affordable sensors [9][10][11]. However, they suffer from some limitations such as their poor selectivity, partial recovery and long response recovery time [12]. To overcome these issues, several strategies have been reported including, but not limited to

Remarkable electronic and optical anisotropy of layered 1T’-WTe₂ 2D materials

• Qiankun Zhang,
• Rongjie Zhang,
• Jiancui Chen,
• Wanfu Shen,
• Chunhua An,
• Xiaodong Hu,
• Mingli Dong,
• Jing Liu and
• Lianqing Zhu

Beilstein J. Nanotechnol. 2019, 10, 1745–1753, doi:10.3762/bjnano.10.170

• changed immediately when the laser state was alternately switched between on and off. Both the response and recovery time are around 200 ms. Furthermore, a distinguishable wavelength-resolved phenomenon can be observed from the two figures. Thus, the 1T’-WTe2 material can be used for wavelength-dependent

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

• was defined as: Here, Ra and Rg are the electrical resistance when the sensor is in air or exposed to the target gas, respectively. The time required for the sensor resistance decrease to 10% or recover to 90% of the original value is called response and recovery time, respectively. (a) XRD patterns

Fe₃O₄ nanoparticles as a saturable absorber for giant chirped pulse generation

• Ji-Shu Liu,
• Xiao-Hui Li,
• Abdul Qyyum,
• Yi-Xuan Guo,
• Tong Chai,
• Hua Xu and
• Jie Jiang

Beilstein J. Nanotechnol. 2019, 10, 1065–1072, doi:10.3762/bjnano.10.107

• ultrafast recovery time of 18–30 ps [3]. FONPs can be classified as a semiconductor material (with a band gap of ≈0.3 eV), which can be modulated by tuning the nanoparticle diameter [4]. For the magnetite (Fe3O4) material of anti-spinel structure, Fe(II) and Fe(III) of the octahedral position of the crystal

Effects of gold and PCL- or PLLA-coated silica nanoparticles on brain endothelial cells and the blood–brain barrier

• Aniela Bittner,
• Angélique D. Ducray,
• Hans Rudolf Widmer,
• Michael H. Stoffel and
• Meike Mevissen

Beilstein J. Nanotechnol. 2019, 10, 941–954, doi:10.3762/bjnano.10.95

• alternative treatment method for injuries of hollow organs, e.g., vessels, offering faster procedure time, immediate watertightness, faster wound healing and reduced recovery time compared to classical microsuturing [3][4][5]. This technique makes use of a degradable polymer scaffold containing albumin and

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

• Engineering, Universiti Teknologi Malaysia, 81310 Skudai, Johor, Malaysia 10.3762/bjnano.10.64 Abstract Nanomaterial-based sensors with high sensitivity, fast response and recovery time, large detection range, and high chemical stability are in immense demand for the detection of hazardous gas molecules

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

• the recovery time include heating or UV irradiating the gas-sensitive film during the recovery phase to ease desorption of molecules from the surface, increasing the flow rate during both detection and recovery phases or further optimizing the sensor parameters such as electrode design or CNT density

Temperature-dependent Raman spectroscopy and sensor applications of PtSe₂ nanosheets synthesized by wet chemistry

• Mahendra S. Pawar and
• Dattatray J. Late

Beilstein J. Nanotechnol. 2019, 10, 467–474, doi:10.3762/bjnano.10.46

• well with the reported 2D transition metal dichalcogenides. A PtSe2 nanosheet-based sensor device was tested for its applicability as a humidity sensor and photodetector. The humidity sensor based on PtSe2 nanosheets showed an excellent recovery time of ≈5 s, indicating the great potential of PtSe2 for

• conductivity of the sensor device, similar to that observed for other 2D materials such as SnSe2 [35], MoS2 [36], BP [26], and MoSe2 [37]. Figure 7b shows a typical current–time (I–t) plot where cycles of 11.3% and 97.3% RH levels were used to calculate the response and recovery time. The response and recovery

• . Figure 7d shows the I–t plot for the photodetector based on PtSe2 nanosheets with a response time of ≈110 s and a recovery time of ≈129 s. Conclusion In conclusion, we report on a wet chemistry method to grow PtSe2 nanosheets. The SEM and TEM analysis confirm the formation of PtSe2 nanosheets. Further

A comparison of tarsal morphology and traction force in the two burying beetles Nicrophorus nepalensis and Nicrophorus vespilloides (Coleoptera, Silphidae)

• Liesa Schnee,
• Benjamin Sampalla,
• Josef K. Müller and
• Oliver Betz

Beilstein J. Nanotechnol. 2019, 10, 47–61, doi:10.3762/bjnano.10.5

• with plasma as for the epoxy casts described above. Traction force experiments A small piece (2 mm × 2 mm) of styrofoam with a human hair of ca. 15 cm in length was glued longitudinally to the surface of the elytron (Figure 5c). For a recovery time of 30 min, the beetles were kept on clean moist filter

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

• , 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

• sensors based on rGO exhibited a rapid and high response to target gas at room temperature. However, these sensors show a common shortage. Since the binding force between graphene and gas molecules is van der Waals force or even covalent bonds [6], the recovery time is too long, sometimes recovery is not

• composites. The ZnO–rGO sensor exhibited a response of 1.2 to NH3 with ultra-fast response/recovery times of 78 s/188 s, which was much better than that of a pure rGO sensor (low response and endless recovery time). The composite sensor with the optimal amount of GO (1.5 mL) was highly sensitive to low

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

• 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

• acetone at 250 °C compared with solid NFs with average diameter of 275 nm. These latter NFs give a response of 60.2 at 270 °C. The response time of WO3 NTs (5 s) is smaller than WO3 NFs (6–13 s) but the recovery time is longer (22 s) than WO3 NFs (4–9 s) because of different desorption rates in NTs

• compared with NFs [102][110]. A similar trend is shown by In2O3 NWs and NTs with similar response times but a longer recovery time for NTs compared with their counterparts [79][133]. Moreover, smaller diameter In2O3 NTs (≈100 nm) exhibited a higher response toward HCHO than larger diameter NTs (≈500 nm or

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

• improved response (τRes = 9 s) and recovery time (τRec = 39 s). The enhanced gas sensing performance and photocatalytic degradation processes are suggested to be attributed to not only the surface plasmon resonance effect, but also due to a Schottky barrier between plasmonic Au and ZnO structures

• 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

• exposure to 4, 6, 8 and 12 ppm NO2 at optimum operating temperature. Interestingly, the sensor response of Au NP/ZnO was fast reaching saturation at concentrations above 8 ppm. The response time (τRes) upon exposure to 10 ppm NO2 was dramatically decreased from 42 s to 9 s and the recovery time (τRec

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

• almost 3 for 400 ppm xylene, while the response and recovery time decreased from about 250 and 500 s to 150 and 450 s, respectively. As illustrated in Figure 5a, when increasing the concentration at 200 °C from 200 to 400 ppm, the sensitivity was improved from 1 to 3, which represents the potential of

• concentrations as low as 200 ppm while the detection sensitivity increased with increasing gas concentration. It was also confirmed that the response and recovery time for sensors decreased dramatically with increasing temperature. The sensitivity of the produced sensor device towards methanol was found to be

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

• . 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

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

• the interaction energy and the degree of adsorption of NO2 and NH3 at room temperature employing a simple descriptive model, the results of which are coherent with those reported in other theoretical works related to gas-adsorption processes on graphene. The recovery time for these devices is

Gas sensing properties of MWCNT layers electrochemically decorated with Au and Pd nanoparticles

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

Beilstein J. Nanotechnol. 2017, 8, 592–603, doi:10.3762/bjnano.8.64

• , the recovery time reveals an opposite trend. This result is explainable considering that the presence of metal NPs on the surface of MWCNTs improves the adsorption of gaseous molecules and therefore the interaction at the interface in the response process. Moreover, this strong interaction kinetically

• hinders the gas desorption in the recovery process. Indeed, the higher operating temperature reduces the recovery time, favoring the desorption process, in all evaluated cases. Considering the sensor operating-temperature effect on the sensing properties, Figure 9 compares the mean sensitivity of pristine

• decreasing concentrations of NO2 at the sensor temperature of 100 °C. C) The corresponding calibration curves. The inset the plot is enlarged in the low concentration range (0.2–1 ppm). Variation of A) the response time (tResponse) and B) the recovery time (tRecovery) of pristine, Au- and Pd-modified MWCNTs