CO Gas Detection Research Articles

Indoor Air Quality System: A Design of Monitoring CO and CO2 Substances for Elderly Home Using IoT

The use of an IoT-based monitoring system for CO and CO2 gases in elderly homes is a necessary innovation for remotely monitoring air quality. This work was successful in establishing a remote monitoring system that can measure CO and CO2 gases utilizing IoT technology combined with Blynk software. The MQ-7 sensors detect CO gas, while the MQ-135 sensors detect CO2. Data from these sensors is delivered to a central server, which then sends it to the I2C 16X2 LCD panel and Blynk software, allowing data visualization via an internet connection. The study's findings indicate that this system can detect and monitor CO and CO2 gas levels with a high degree of precision. This device can also monitor air quality in real time using the Blynk software. As a result, users may accurately monitor air quality (CO and CO2 gases) in elderly homes.

Enhancement of CO gas sensing with ZnO nanostructures on MWCNTs films

CO gas sensing properties of 1-D ZnO nanostructures deposited on films of Multi-Wall carbon nanotubes were investigated using a vapor transport approach. X-ray powder diffraction, scanning electron microscopy, transmission electron microscopy, high resolution transmission electron microscopy, energy dispersive X-ray, Raman spectroscopy, diffused reflectance spectroscopy, and photoluminescence, techniques were used to carry out the structural, morphological, and optical characterizations. The development of carbon-doped hybrid MWCNTs/ZnO nanostructures was demonstrated by the current results. The synthesized nanostructures were dense tapering belts and pedal-like crystalline structures as evidenced by their structural and morphological characteristics. Multiple networks of pure ZnO and hybrid MWCNTs-ZnO nanostructures were used to synthesize the gas sensors. Doped ZnO nanostructures sensing technique for CO gas detection was investigated in the present study. The combined impact of ZnO and MWCNTs was shown to be beneficial in boosting the response towards CO gas, as the response to CO gas at a concentration of 20 parts per million (ppm) was found to be five-times greater than that of ZnO sensors with good stability.

Effect of doping concentration of Cu2+ ion on ZnO thin film for detection of CO gas

Effect of doping concentration of Cu2+ ion on ZnO thin film for detection of CO gas

DFT insights into the electronic properties and gas sensing performance of C19X (X = C, N, and Si) nanocages for the detection of CO2, CO, N2, and H2 gases

The development of carbon nanocage-based sensors for the detection of toxic and pollutant gases has attracted significant attention from researchers. In this computational study, the interactions of CO2, CO, N2, and H2 gases with the C19X nanocages (X = C, N, and Si) were evaluated using the M062X/6-31G(d) level of density functional theory (DFT) calculations. The results demonstrated a reduction in the energy gap (Egap) across all studied systems, especially pronounced in the C19N and C19Si nanocages, compared to the complexes with a higher priority of the C19Si nanocages. The gas molecules were found to have weak adsorption in all the C20 nanocage complexes, while the adsorption of CO gas was more pronounced in the C19N and C19Si nanocages compared to the other gases studied. A quantum theory of atoms in molecule (QTAIM) analysis was conducted to examine the interactions and their features, through which the physical interactions that contribute to the formation of the complexes were identified. Further electrical characterizations revealed that the C19Si nanocage has a high sensitivity for the detection of CO gas, making it a promising sensor material. In conclusion, the engineered C19N and C19Si nanocages demonstrated significant improvements over the original C20 nanocage in terms of adsorption capabilities for CO2, CO, N2, and H2 gases, making them promising candidates for sensor applications.

A portable gas sensor based on In2O3@CuO P–N heterojunction connected via Wi-Fi to a smartphone for real-time carbon monoxide determination

This research presents a compact portable electronic gas sensor that can be monitored through a smartphone application. The smart sensor utilizes three state-of-the-art sensors. The sensors integrate an ESP8266 microcontroller within the same device. This facilitates their integration with the electronics and enhances their performance. Herein, primarily focuses on utilizing the sensor to detect carbon monoxide. This article outlines the fabrication process of a gas sensor utilizing a P–N heterojunction, eliminating the need for a binder. The sensor consists of CuO/copper foam nanowires and hierarchical In2O3. In order to verify the system’s functionality, it underwent testing with various levels of CO concentrations (10–900 ppm), including particular tests designed to examine the device’s performance in different humidity and temperature circumstances. A mobile application for the provision of monitoring services has been developed at last. To process the information obtained from the gas sensor, an algorithm has been constructed, trained, and integrated into a smartphone for this purpose. This research demonstrated that a smartphone-coupled gas sensor is a viable system for real-time monitoring and the detection of CO gas.

Study of carbon monoxide adsorption on B-N doped hydrogenated Sn nanoribbons towards nanosensor applications

This study utilized Van der Waals corrected density functional theory (DFT) and nonequilibrium Green's function (NEGF) to consider the potential of hydrogenated Armchair stanene nanoribbons of width 8 (HASnNR(8)) for CO gas detection. The study analyzed the most stable adsorption configuration, charge transfer, electronic transport, adsorption energy, sensitivity and electronic properties of CO gas molecules on HASnNR(8), both before and after B-N doping. The results showed that B-N doping led to a significant increase in adsorption energy and a gap opening at the Gamma point, resulting in semiconductor behavior. Analysis of charge transfer indicated that CO molecules acted as donors to HASnNR(8). Moreover, there was a notable change in the transmission functions of CO adsorbed on B-N doped HASnNR(8) compared to pure HASnNR(8). Based on the I-V characteristics, the study concluded that CO molecules could be easily detected after B-N doping. Finally, the study performed a recovery time analysis and sensitivity CO adsorbed on bare and B-N doped HASnNR(8) surfaces, with the results indicating that B-N doped HASnNR is a promising material for CO molecule sensing applications.

A DFT study of natural-based materials kaempferol and apigenin for hazardous CO and CO2 gas detection

In this research, the chemical and structural attributes of two flavonoid compounds, Kaempferol and Apigenin, have been investigated employing DFT. These compounds are considered the most promising options for high-sensitivity gas sensors. Applying DFT computations, the adsorption behaviour of typical gas molecules over Kaempferol and Apigenin was studied. Apigenin (Kaempferol) could respond to physisorption of CO and CO2 molecules sensitively due to their considerable charge transfer (CT). Particularly, notable progress in transport performance is induced by absorption of both CO and CO2, which makes Apigenin (Kaempferol) an appropriate option to detect CO and CO2 molecules sensitively. In order to examine potential application of natural products in sensing toxic gases, we deeply believe that this work supplies guidance for research groups.

Surface modification of Co3O4 nanosheets through Cd-doping for enhanced CO sensing performance.

The detection of hazardous CO gas is an important research content in the domain of the Internet of Things (IoT). Herein, we introduced a facile metal-organic frameworks (MOFs)-templated strategy to synthesize Cd-doped Co3O4 nanosheets (Cd-Co3O4 NSs) aimed at boosting the CO-sensing performance. The synthesized Cd-Co3O4 NSs feature a multihole nanomeshes structure and a large specific surface area (106.579 m2·g-1), which endows the sensing materials with favorable gas diffusion and interaction ability. Furthermore, compared with unadulterated Co3O4, the 2 mol % Cd-doped Co3O4 (2% Cd-Co3O4) sensor exhibits enhanced sensitivity (244%) to 100 ppm CO at 200°C and a comparatively low experimental limit of detection (0.5 ppm/experimental value). The2% Cd-Co3O4 NSs show good selectivity, reproducibility, and long-term stability. The improved CO sensitivity signal is probably owing to the stable nanomeshes construction, high surface area, and rich oxygen vacancies caused by cadmium doping. This study presents a facile avenue to promote the sensing performance of p-type metal oxide semiconductors by enhancing the surface activity of Co3O4 combined with morphology control and component regulation.

Advance Multi-Gas Detection System for Optimal Safety

Indoor air quality is a growing concern, particularly the concentration of carbon dioxide (CO2) and other hazardous gases, which can pose significant health risks and diminish safety. Recognizing the critical nature of this issue, this paper detailsthe development of an advanced environmental monitoring system designed to detect elevated levels of CO2 and other potentially dangerous gases. Our approach synthesizes various research methods, including requirement gathering, literature review, and user surveys, to inform system conception and implementation. The resulting device integrates highly sensitive sensors for CO2, CO, LPG, smoke, and additional hazardous gas detection, all governed by a microcontroller at the system's nucleus. This technology is augmented by a comprehensive alarm strategy—encompassing audio alerts, text messages, emails, and mobile application notifications—together with a user-friendly display interface. The system is also endowed with Internet of Things (IoT) capabilities, offering users the convenience of real-time monitoring and control through a web dashboard and a dedicated mobile application. Moreover, the device boasts the ability to monitor environmental parameters like temperature and humidity, providing a holistic view of indoor air conditions. Key results indicate a significant improvement in detection response time and accuracy, with the enhanced communication features facilitating swift and effective alerts to users. These advancements mark a stride toward safer indoor environments, potentially mitigating the risks associated with poor air quality.

CVD-fabricated Co3O4-Co3S4 heterojunction for ultra-sensitive detection of CO in SF6 discharge decomposition products

SF6-insulated electrical equipment will produce CO gas when it fails. Therefore, effective detection of CO gas can determine whether SF6-insulated electrical equipment is operating normally. In this paper, the p-Co3O4/n-Co3S4 heterojunction was fabricated by two-phase hydrothermal and chemical vapour deposition (CVD) methods for CO detection. The gas sensitivity of the p-Co3O4/n-Co3S4 heterojunction to CO in both the air and SF6 background was studied for the first time. The results show that the best operating temperature of the sensor is 200°C in both air and SF6 environment. The sensor showed a better response in the SF6 background than in the air background, but the recovery time was longer in the air background. At the same time, the sensor has good selectivity for CO in both environments, resistance to moisture, and long-term stability. In addition, it is proven by first principles that the adsorption performance of the p-Co3O4/n-Co3S4 heterojunction on CO is better than that of the p-Co3O4 and n-Co3S4, and the interaction between p-Co3O4/n-Co3S4 heterojunction and CO is further described by differential charge density and state density curves. The designed and constructed carbon monoxide detection system can realise the effective detection and alarm of carbon monoxide gas concentration.

Nanocubes SnO2 Thin Films for the Detection of CO Gas

Nanocubes SnO2 thin films have been prepared by spray pyrolysis method, under optimized conditions. The as prepared thin films were investigated by using X-ray diffraction, Field emission scanning electron microscope, Energy dispersive X-ray analysis, Transmission electron microscopy and Surface area electron diffraction pattern to know crystal structure, surface morphology, constituents of the elements and microstructure properties. The gas sensing performance was studied as a function of operating temperature. CO gas detection was also investigated with stability of thin films were studied and discussed.

CO gas adsorption and detection ability of boron nitride nanosheet doping with group 8B transition metal: A theoretical investigation

CO gas adsorption and detection ability of boron nitride nanosheet doping with group 8B transition metal: A theoretical investigation

Gas sensing potential of monolayer MoB: A first principles study

Monolayer MoB is one of MBenes with a structure similar to graphene. Through first-principles calculations, we have investigated the adsorption characteristics of monolayer MoB for CO, NO, SO, SO2 gases. The results show that CO and NO tend to adsorb at the top of Mo, and SO and SO2 tend to adsorb at the top of B. The adsorption energies of all gas molecules are negative, with the smallest adsorption energy for SO. All gas molecules are charge acceptors, with SO2/MoB having the largest charge transfer value of 0.977 eV. According to the transition state theory, the shortest recovery time for monolayer MoB adsorbed CO molecule. This means that the process of CO adsorption by monolayer MoB is reversible and monolayer MoB has the potential to be used as a CO gas detection sensor. At room temperature, it is almost impossible for monolayer MoB to recover its initial state after adsorption of NO, SO and SO2. In addition, MoB has high sensitivity in detecting NO, SO and SO2 due to its low adsorption energy for NO, SO and SO2, and has the potential to be a sensitive irreversible detection sensor for detecting NO, SO and SO2.

CuO surface doped In2O3/CeO2 nanofibers for ppb-ppm level carbon monoxide gas detection in low-temperature

In this work, we designed and prepared CuO-loaded In2O3/CeO2 nanofiber heterojunctions, which are promising for trace CO gas detection. We characterized the materials, confirmed the morphology of the nanofibers and structure of the p-n heterojunctions, and analyzed the effect of morphology and structure on the gas sensing performance. In gas sensing tests, the sensor is found to show a low optimum operating temperature of 70 °C, with a limit of detection that reaches as low as 50 ppb. At concentrations ranging from 50 ppb to 10 ppm, the sensor shows a sensitive and linear response for CO gas. In particular, the sensor shows a response (Ra/Rg) of 11.7–10 ppm CO gas, and a response/recovery time of 125 s/12 s for 2 ppm CO gas. In addition, we tested the selectivity, humidity response and long-term stability of the gas sensors. Finally, based on the structure of the materials, we propose a mechanism for the enhanced CO gas sensing performance.

Density Functional Theory Study of Cu-Modified B12N12 Nanocage as a Chemical Sensor for Carbon Monoxide Gas.

The development of efficient B12N12-based toxic gas sensors has received considerable attention from the scientific community. Thus, in this regard, quantum chemical calculations were performed using density functional theory (DFT) at the B97D/6-31G(d,p) level for all of the studied systems. Modification of copper on B12N12 results in five optimized structures, named CuB11N12 and B12N11Cu (doped structures), Cu@b66 and Cu@b64 (decorated structures), and Cu@B12N12 (encapsulated structure). The results indicate that the CO gas weakly physisorbed on the B12N12 nanocage. It was found that the gas adsorption performance of B12N12 is improved due to the introduction of the Cu atom, but the interaction between CO and B12N11Cu, Cu@B12N12, Cu@b64, and Cu@b66 nanocages is strong, limiting the applications as a sensor. Particularly, the CuB11N12 system shows moderate adsorption (Eads = -0.6 eV) and a high electronic sensitivity (ΔEgap = 81.6%) toward CO gas, compared to other modified systems. Furthermore, based on the sensor performance analysis, it was found that CuB11N12 presented low recovery time (14 ms) and high selectivity for CO detection, making it a promising fast response sensor. Finally, our results demonstrated the capability of CuB11N12 as a superior sensor material for applications involving the selective detection of CO gas.

Heterostructure nanoarchitectonics with ZnO/SnO2 for ultrafast and selective detection of CO gas at low ppm levels

Heterojunction-based gas sensors are very attractive as they substantially improve the sensing characteristics due to the effective potential barrier present at the interface. Taking the advantages of two excellent semiconducting gas sensing materials i.e., SnO2 and ZnO, herein, we have constructed ZnO/SnO2 heterojunction by the combination of vacuum evaporation and r.f. sputtering or atomic layer deposition techniques. The ZnO/SnO2 heterostructure with optimized thickness of ZnO (∼10 nm) shows a 6-fold enhancement in sensing response compared to bare SnO2 films against CO gas. The sensing responses of 81 and 85 % have been obtained for ZnO/SnO2 heterostructures with ZnO deposited by sputtering and atomic layer deposition (ALD) methods, respectively, against 91 ppm of CO gas with an estimated limit of detection of 1.67 and 0.37 ppm. The ALD ZnO/SnO2 sample displays an extremely fast response time of 5 s. The heterostructure sensors are also highly selective towards CO gas in the presence of other interfering toxic agents. The enhanced sensing characteristics of ZnO/SnO2 are assigned to the formation of n-n heterojunction as depicted by X-ray photoelectron spectroscopic band alignment study and the strong CO adsorption on ZnO surface as derived from density functional theory calculations.

Implementasi Monitoring Dan Notifikasi Kualitas Udara Menggunakan Arduino Berbasis IoT

The results of this study are an IoT-based tool that can monitor air quality and data, the data. which is very influential on the health of those who inhale it, especially humans. By using sensors MQ7 and DHT11 where these sensors have their respective functions, MQ7 functions to detect CO gas (carbon monoxide) while DHT11 functions to detect temperature and humidity, which can know the air quality every day. In this study using the prototype method to build hardware later. To be able to provide accurate and precise information to users and the public to increase self-awareness in reducing air pollution levels. The first stage of this research is to collect data for 7 days in March 2022 in Penukal Abab Lematang Ilir Regency. Furthermore, the data that has been obtained the results are calculated using excel. The result of calculating the highest average value for CO is 9.99 ppm on March 7, 2022, at 16:41 and the lowest average value of 1.83 ppm on March 1, 2022, at 10:34. The average for the overall value is 3.37ppm, so it can be concluded that the air quality in Penukal Abab Lematang Ilir Regency is still identified as good.

CO sensing properties of nanostructured WSe2/GaN and MoSe2/GaN based gas sensors

The sensing properties of GaN and hydrothermal synthesized transition metal di-selenides nanostructure decorated WSe 2 /GaN and MoSe 2 /GaN hybrid structures are reported for 100 ppm CO gas for temperature range of 27 °C–250 °C. The fabricated devices divulged that Schottky Barrier Height increases from 0.6 eV to 1.2 eV with increment in temperature while vice versa was perceived for series resistance, except for MoSe 2 /GaN structure. The gas sensing measurements revealed that the threshold temperature for CO sensing for GaN, WSe 2 /GaN and MoSe 2 /GaN based sensors was 100 °C, 100 °C and 150 °C along with a peak response value of 23.3 %, 38.8 % and 43.1 %, respectively. The gas sensing data displayed a highly competitive response & recovery time as all the fabricated devices were able to detect CO within 78 s of exposure. The recovery time of the devices varied in a similar fashion, demonstrating the promising potential of W(Mo)Se 2 /GaN hybrid structures for efficient CO gas detection. • GaN & TMDC hybrid structure based sensor for CO gas sensing. • Hydrothermally synthesized WSe 2 and MoSe 2 nanostructured on GaN for CO gas sensing. • Threshold temperature for CO sensing for GaN & its heterostructure varies between 100 o C- 150 °C. • MoSe 2 /GaN & WSe 2 /GaN devices with highly competitive response & recovery time is fabricated.

Enhanced Gas Sensing Performance of Nano‐Structured Ta2O5‐SnO2 Composite for Low Concentration CO Detection

AbstractIn the present work, the superior performance of nanostructured Ta2O5‐SnO2 nanocomposite homo‐junction was demonstrated for the detection of CO gas at low concentration (5‐10 ppm) and low operating temperature (50 °C). The gas sensing performance of this material is comparable to the state of the art materials reported to date in the literature. In addition, the material exhibits high selectivity to CO gas over other interfering gases such as CO2, H2, CH4, NO2, and SO2 etc. The sensing performance of the composite was significantly higher than its individual oxides. The composite is robust and shows good reproducibility and chemical stability with low response and recovery time. The strategy employed herein to create homo‐junction nanocomposites of semiconducting metal oxides significantly improved the sensitivity and selectivity to CO gas closer to room temperature and thus could pave the way for the development of efficient homo‐junction nanocomposites for gas sensing applications.

Dual channel detecting of CO in a metal complex gel system: Phase transition and fluorescence enhancement

A C3 symmetric molecule BTBM bearing benzimidazole moiety was design and synthesized. BTBM could form supramolecular gel in glacial acetic acid and exhibit fluorescent emission. By complexing with Pd2+, metal organic gel could be obtained and the fluorescent intensity of the benzimidazole moiety was weaken. When the metal organic gel was placed in CO gas atmosphere, the metal organic gel was collapsed and the fluorescence recovered again. This work provide a dual channel method including the phase transition and fluorescent intensity change to detect CO gas by naked eyes.