CO2 Sensor Research Articles

Research on Fire Detection of Cotton Picker Based on Improved Algorithm.

According to the physical characteristics of cotton and the work characteristics of cotton pickers in the field, during the picking process, there is a risk of cotton combustion. The cotton picker working environment is complex, cotton ignition can be hidden, and fire is difficult to detect. Therefore, in this study, we designed an improved algorithm for multi-sensor data fusion; built a cotton picker fire detection system by using infrared temperature sensors, CO sensors, and the upper computer; and proposed a BP neural network model based on improved mutation operator hybrid gray wolf optimizer and particle swarm optimization (MGWO-PSO) algorithm based on the BP neural network model. This algorithm includes the introduction of a mutation operator in the gray wolf algorithm to improve the search ability of the algorithm, and, at the same time, we introduce the PSO algorithm idea. The improved fusion algorithm is used as a learning algorithm to optimize the BP neural network, and the optimized network is used to process and predict the data collected from temperature and gas sensors, which effectively improves the accuracy of fire prediction. The sensor measurements were compared with the actual values to verify the effectiveness of the GWO-PSO-optimized BP neural network model. Once experimentally verified, the improved GWO-PSO algorithm achieves a correlation coefficient R of 0.96929, a prediction accuracy rate of 96.10%, and a prediction error rate of only 3.9%, while the system monitors an accurate early warning rate of 96.07%, and the false alarm and omission rates are both less than 5%. This study can detect cotton picker fires in real time and provide timely warnings, which provides a new method for the accurate detection of fires during the field operation of cotton pickers.

Module-A Sensor Performance Tests Used In Laboratory-Type Silage Production, Data Acquisition and Control System

The primary objective of this study is to investigate the performance of sensors integrated into the laboratory-type silage production, data acquisition, and control system. The system is a PLC-controlled and multi-sensor based system designed to enable numerous studies aimed at improving silage quality. It consists of grinding, weighing, silo, data acquisition, and control units. It provides the capability to apply/change/simulate various parameters during the silage production process. The silo unit is composed of two modules, module-A (compression principle) and module-B (vacuum principle). This research focuses on measurements conducted with plexiglass silos (24,5 cm3) in the module-A unit. This silos were equipped with oxygen sensor (±0-100 %), carbon dioxide sensor (0-5000 ppm), temperature sensor (±0.53 °C, -10 – 80 °C), humidity sensor (0-100 %), pH sensor (2-12), and pressure sensor (± 1000 mbar). The research utilized second-crop silage corn material with a dry matter content (DM) of 32%. Four different compaction forces were applied during the experiments. Sensor measurements were recorded as one data per second by connecting them to the data recording unit using analog sensors. Due to the abundance of data, average values were taken. The data were displayed and monitored on the HMI operator panel programmed with GOP HMI editor software and stored in Excel format. The measurements were carried out during the silage (aerobic) and post-silage (anaerobic) periods. According to the research results, it was observed that the six tested sensors performed accurate readings. However, issues related to the oxygen and carbon dioxide sensors were encountered. Due to the difficulty in reading at points with very low oxygen content, it was decided to be supported by controlling with sensors of different types and specifications. During measurements conducted at the compression stage in module-A, the pressure values varied between 0,34-0,67 bar with increasing compaction force. The temperature ranged from 16-33 °C, humidity from 60-100 %, pH from 5,8-5,6 O2 level from 8,1-0 mmol L-1, and CO2 level from 0-40 mmol L-1. The measured value ranges in silage varied depending on the duration of silage, and accurate measurements were obtained in the desired direction. Sensor placements were updated considering measurement accuracy.

Achieving bi-function of enhanced CO2 gas sensing and orange-red light emission of La2O2CO3 1D nanostructures via Eu3+ doping

Bi-functional nanomaterials with gas sensing and luminescence are more attractive and promising compared with the counterpart single functional nanomaterials, and have become a hotspot subject. Herein, La2O2CO3 and La2O2CO3:Eu3+ one-dimensional (1D) nanostructures including nanofibers, hollow nanofibers and nanobelts are rationally designed and are synthesized by a facile electrospinning via regulating spinning parameters. Excellent bi-functionalities of enhanced CO2 gas sensing and intense orange-red light emission are achieved via Eu3+ doping in 1D La2O2CO3 nanostructures. CO2 sensors based on La2O2CO3:Eu3+ 1D nanostructures display superior selectivity, high response, short response/recovery time and good reproducibility. With respect to response time (2 s) and recovery time (9s), the La2O2CO3:Eu3+ hollow nanofibers sensor is the best of the presently reported La2O2CO3-based CO2 sensors. The enhanced CO2 sensing mechanism of La2O2CO3:Eu3+ 1D nanostructures can be contributed to the lattice distortion and increase of OH- groups due to Eu3+ doping. Meanwhile, La2O2CO3:Eu3+ 1D nanostructures emit bright orange-red light under 274-nm UV light excitation. The luminescent characteristics are easily adjusted by varying the doping concentrations of Eu3+ ions and changing the morphology of 1D nanostructures. Rationally devised and prepared La2O2CO3:Eu3+ 1D nanostructures with different morphologies can better meet the applications in CO2 gas sensing and rare earth luminescence fields. The preparation strategy of 1D nanostructures is established and the formation mechanism is advanced. The design concepts and fabrication methods established in this work can be extended to prepare other 1D nanostructured materials, promoting the developments of 1D bi-functional nanostructures in the fields of gas sensing and luminescence.

Direct ink writing of nickel oxide-based thin films for room temperature gas detection

The rapid industrial growth and increasing population have led to significant pollution and deterioration of the natural atmospheric environment. Major atmospheric pollutants include NO2 and CO2. Hence, it is imperative to develop NO2 and CO2 sensors for ambient conditions, that can be used in indoor air quality monitoring, breath analysis, food spoilage detection, etc. In the present study, two thin film nanocomposite (nickel oxide-graphene and nickel oxide-silver nanowires) gas sensors are fabricated using direct ink writing. The nano-composites are investigated for their structural, optical, and electrical properties. Later the nano-composite is deposited on the interdigitated electrode (IDE) pattern to form NO2 and CO2 sensors. The deposited films are then exposed to NO2 and CO2 gases separately and their response and recovery times are determined using a custom-built gas sensing setup. Nickel oxide-graphene provides a good response time and recovery time of 10 and 9 s, respectively for NO2, due to the higher electron affinity of graphene towards NO2. Nickel oxide-silver nanowire nano-composite is suited for CO2 gas because silver is an excellent electrocatalyst for CO2 by giving response and recovery times of 11 s each. This is the first report showcasing NiO nano-composites for NO2 and CO2 sensing at room temperature.

The influence of annealing temperature on the gas sensing properties of multifunctional hematite (α-Fe2O3) films

In this study, hematite (α-Fe2O3) were prepared using direct solution spin coating and the changes of some physical properties with annealing temperature (400, 500 and 600 °C) for 2 h were investigated. The sensors annealed at 400 °C, 500 °C and 600°C are referred to as F400, F500 and F600 respectively. The X-ray diffraction patterns of the prepared samples confirm the polycrystalline nature of the rhombohedral crystal structure of hematite (α-Fe2O3). The surface roughness parameters (SA-SQ) of the α-Fe2O3 films decreased drastically with increasing annealing temperature from 400 to 600 °C (57.47–68.08/13.63–17.13). The direct optical band gap values were estimated from absorption measurements and ranged from 2.77 to 2.52 eV. The electrical resistivity measurement at room temperature of the samples decreased with increasing annealing temperature from 400 to 600 °C. The response of the CO sensor of F400, F500 and F600 was found at 180 °C. The response to 1 ppm CO gas was calculated to be 1.45%, 8% and 10% for F400, F500 and F600 respectively. The wettability test of the samples showed a water contact angle (WCA) of less than 90°, demonstrating the hydrophilic surface especially for the samples annealed at 500 °C.

Noble metal (Pd, Pt)-functionalized WSe2 monolayer for adsorbing and sensing thermal runaway gases in LIBs: a first-principles investigation.

This research using the first-principles theory introduces Pd- and Pt-functionalized WSe2 monolayers as promising materials for detecting three critical gases (H2, CO, and C2H4), to evaluate the health of Li-ion battery (LIBs). Various sites on the pristine WSe2 monolayer are considered for the functionalization with Pd and Pt atoms. The adsorption performances of the determined Pd- and Pt-WSe2 monolayers upon the three gases are analyzed by the comparative highlight of the adsorption energy, bonding behavior and electron transfer. Subsequently, an examination of the electronic properties of these monolayers uncovers their semiconducting nature and sensing mechanisms, while the sensing responses are quantified based on variations in their bandgaps. Furthermore, the practical applications of these monolayers are confirmed by assessing their recovery properties. The findings in this study concretely serve the Pd-WSe2 monolayer as a promising CO and C2H4 gas sensor, and the Pt-WSe2 monolayer as an optimal for H2 gas sensor. These findings not only underscore the promising sensing potential of WSe2-based materials for indicating thermal runaway in LIBs, but also emphasize the critical importance of metal selection for surface-functionalization on the nano-surface in the gas sensing technologies.

Ultralow-power carbon dioxide sensor for real-time breath monitoring

Ultralow-power carbon dioxide sensor for real-time breath monitoring

Development of a bioreactor with an integrated non-dispersive infrared CO2 sensor for rapid and sensitive detection of Cr(VI) toxicity in water

Development of a bioreactor with an integrated non-dispersive infrared CO2 sensor for rapid and sensitive detection of Cr(VI) toxicity in water

Practical, low-cost integrity testing of diesel particle filters using remote sensing measurement at the campus entrance gate.

This work investigates the detection of defunct or absent diesel particle filters by drive-through remote sensing measurement at the Czech University of Life Sciences main vehicular entrance gate. An exhaust sample was collected by a line attached to the road surface in the center of the travel lane. A non-volatile particle number (nvPN) counter and electric mobility particle size classifier were used to measure particle number concentrations, and an FTIR analyzer was used to measure CO2, CO, and NO concentrations. Of 59.7% of 526 entering vehicles, peak CO2 concentrations above 100ppm were observed, suggesting that the entrance gate is ideal for sampling-style remote sensing measurements due to high signal strength and controlled spacing between vehicles. On 48 vehicles, the measurements were compared to a 10-s periodic technical inspection (PTI) style measurement of tailpipe nvPN concentrations at idle. The results indicate nearly absolute agreement in distinguishing diesel vehicles with and without a functional DPF, with one outlier with a relatively weak CO2 signal and weak correlation between roadside nvPN and CO2 concentrations. Using a linear regression approach to calculate the remote sensing emissions factors (EF) and restricting the data to those with peak CO2 at least 100ppm yielded an absolute agreement not only between tailpipe nvPN concentrations at idle and remote sensing nvPN EF but also between tailpipe nvPN and roadside concentration of both nvPN and total particle number in 25-560nm size bins. The reported setup presents, in the authors' opinion, a relatively simple, robust, non-obtrusive, and practical means of checking DPF functionality in locations interested in excluding high emitters, such as university campuses, airports, large parking garages, national park entrances, and similar locations where entering vehicles are fully warmed up and not cooled down by extended waiting in line. Relatively strong CO2 signal yielding high accuracy of detection of non-DPF diesels with laboratory instrument presents, in the opinion of the authors, a very high chance of successful exploitation of diffusion chargers, nvPN counters intended for PTI use in several EU countries, and other low-cost particle number sensors, with detection limit in thousands of #/cm3, and possibly low-cost black carbon monitors, along with a low-cost NDIR CO2 sensor and a camera or other means of identifying individual tested vehicles, for detecting defunct diesel particle filters. The CO2 signal alone can identify vehicles using internal combustion engines. Extending this measurement to CO and NO concentrations may also detect non-functional three-way and NOx-reducing catalysts, as demonstrated on three L-category vehicles, one quad, and two motorcycles. The setup also could be used as a drive-through, loaded-mode PTI test.

Research Progress of MEMS Gas Sensors: A Comprehensive Review of Sensing Materials.

The MEMS gas sensor is one of the most promising gas sensors nowadays due to its advantage of small size, low power consumption, and easy integration. It has been widely applied in energy components, portable devices, smart living, etc. The performance of the gas sensor is largely determined by the sensing materials, as well as the fabrication methods. In this review, recent research progress on H2, CO, NO2, H2S, and NH3 MEMS sensors is surveyed, and sensing materials such as metal oxide semiconductors, organic materials, and carbon materials, modification methods like construction of heterostructures, doping, and surface modification of noble metals, and fabrication methods including chemical vapor deposition (CVD), sputtering deposition (SD), etc., are summarized. The effect of materials and technology on the performance of the MEMS gas sensors are compared.

Technical note: A low-cost, automatic soil–plant–atmosphere enclosure system to investigate CO2 and evapotranspiration flux dynamics

Abstract. Investigating greenhouse gases (GHGs) and water flux dynamics within the soil–plant–atmosphere interphase is key for understanding ecosystem functioning, as they reflect the ecosystem's responses to environmental changes. Understanding these responses is essential for developing sustainable agricultural systems that can help to adapt to global challenges such as increased drought. Typically, an initial understanding of GHGs and water flux dynamics is gained through laboratory or greenhouse pot experiments, where gas exchange is often measured using commercially available manual closed-chamber (leaf) systems. However, these systems are rather expensive and often labor-intensive, thus limiting the number of different treatments and their repetitions that can be studied. Here, we present a fully automatic, low-cost (EUR <1000 per unit) multi-chamber system based on Arduino, termed “greenhouse coffins”. It is designed to continuously measure canopy CO2 and evapotranspiration (ET) fluxes. It can operate in two modes: an independent and a dependent measurement mode. The independent measurement mode utilizes low-cost NDIR (non-dispersive infrared) CO2 (K30 FR) and relative humidity (SHT31) sensors, thus making each greenhouse coffin a fully independent measurement device. The dependent measurement mode connects multiple greenhouse coffins via a low-cost multiplexer (EUR <250) to a single infrared gas analyzer (LI-850, LI-COR Inc., Lincoln, USA), allowing for measurements in series, achieving cost efficiency while also gaining more flexibility in terms of target GHG fluxes (potential extension to N2O, CH4 and stable isotopes). In both modes, CO2 and ET fluxes are determined through the respective concentration increase during closure time. We tested both modes and demonstrated that the presented system is able to deliver precise and accurate CO2 and ET flux measurements using low-cost sensors, with an emphasis on calibrating the sensors to improve measurement precision. By connecting multiple greenhouse coffins via our low-cost multiplexer to a single infrared gas analyzer in the dependent mode, we could additionally show that the system can efficiently measure CO2 and ET fluxes in a high temporal resolution across various treatments with both labor and cost efficiency. Therefore, the developed system is expected to be a valuable tool for conducting greenhouse experiments, enabling comprehensive testing of plant–soil dynamic responses to various treatments and conditions.

High-sensitivity real-time monitoring of pH and respiration activity unveils metabolic dynamics in shake flask cultures.

Erlenmeyer shake flasks are widely used during the first steps of bioprocess development. Despite their broad application in academia and industry, shake flasks usually lack standardized and user-friendly online monitoring techniques. In this work, the pH and Respiratory Activity MOnitoring System (pH-RAMOS) for the non-invasive online measurement of the oxygen transfer rate (OTR), carbon dioxide transfer rate (CTR), and pH in up to eight parallel shake flasks under sterile conditions is presented. The OTR and CTR are quasi-continuously measured in the headspace of the shake flasks using dedicated oxygen and carbon dioxide sensors, enabling precise respiratory quotient (RQ) evaluation. Self-adhesive pH sensor spots are used for the high-frequent real-time pH monitoring of the culture. These prototype pH sensor spots stand out due to their simple sterilizability and subsequent one-point calibration in the cultivation medium. The long-term stability of the pH sensor spots was assessed in a 28-day long abiotic experiment. The novel pH-RAMOS was validated with different eukaryotic and prokaryotic microorganisms, such as Ogataea polymorpha, Ustilago trichophora, and Vibrio natriegens. The combination of online OTR, CTR, RQ, and pH signals allowed for identifying various metabolic phenomena, such as oxygen limitations, substrate limitations, diauxies, and the production or consumption of specific compounds, based on their degree of reduction or change of pH. The high-frequent and sensitive pH-monitoring was particularly advantageous for registering subtle and transient metabolic phenomena.

Chloride Interferences in Wet Chemical Oxidation Measurements: Plausible Mechanisms and Implications.

Wet chemical oxidation (WCO) methods measure total organic carbon (TOC) in aqueous solutions through the formation and detection of carbon dioxide (CO2). Prior research documents chloride (Cl-) interference during WCO. However, the mechanism that determines WCO interference is not established. We investigate WCO and find that formic acid exhibits TOC recovery (89-108%) within measurement uncertainty in the presence of Cl-, while acetic acid recovery is substantially reduced (3-67%). We postulate that chlorine radical (•Cl) formation during WCO alters oxidation pathways for organic compounds with methyl groups to form stable halogenated organic species that are thus not detected as CO2, reducing observed TOC recovery. We develop a kinetic model of elementary step reactions that reproduces observed TOC recoveries at multiple organic (1 and 5 ppm of C) and Cl- (>0.01 M) concentrations for both acetic and formic acids. Independent experiments with pyruvic acid and different halogen salts are consistent with the proposed mechanism. Our findings provide a plausible mechanistic explanation for Cl- interference in WCO-derived TOC measurements of environmental samples for which halogenated salts are present. A plausible mechanism provides a more complete understanding of how and why the TOC is biased low in environmental aquatic samples from saline environments when WCO is employed.

Adaptive sliding mode control of petrochemical flare combustion process based on radial basis function network

Steam-assisted combustion elevated flares are currently the most widely used type of petrochemical flares. Due to the complex and variable composition of the waste gas they handle, the combustion environment is severely affected by meteorological conditions. Key process parameters such as intake composition, flow rate, and real-time data of post-combustion residues are difficult to measure or exhibit lag in data availability. As a result, the control methods for these flares are limited, leading to poor control effectiveness. To address this issue, this paper proposes an adaptive sliding mode control method based on the Radial Basis Function (RBF) network. Firstly, the operational characteristics of the petrochemical flare combustion process are analyzed, and a control model for the combustion process is established based on carbon dioxide detection. Secondly, an RBF neural network-based unknown function approximator is designed to identify the nonlinear part of the actual operating system. Finally, by combining the control model of the petrochemical flare combustion and designing the RBF sliding mode controller with its adaptive control law, fast and stable control of the flare combustion state is achieved. Simulation results demonstrate that the designed control strategy can achieve tracking control of the petrochemical flare combustion state, and the adaptive law also accomplishes system identification.

Multi-resonator T-type photoacoustic cell based photoacoustic spectroscopy gas sensor for simultaneous measurement C2H2, CH4 and CO2

Multi-resonator T-type photoacoustic cell based photoacoustic spectroscopy gas sensor for simultaneous measurement C2H2, CH4 and CO2

How to improve the perceived health, comfort, and well-being of primary school teachers? A quantitative self-reported survey during the COVID-19 pandemic in Scotland

Teachers are among the most stressed professionals, for whom the built environment has an influence. In addition, the COVID-19 pandemic has increased the pressure on schools, where enhanced ventilation is deemed essential to help reduce virus-laden particles in classrooms. Good Indoor Air Quality (IAQ) is required to maintain an adequate level of comfort, health, and well-being. Therefore, solutions to improve IAQ quickly and cheaply are essential. As such, the Scottish Government has funded Local Authorities to purchase CO2 sensors for school classrooms. This study explores two interventions designed to improve the quality of indoor air. The first one by raising the awareness of the teachers on ventilation strategies via a webinar. The second one by deploying devices that visually inform the occupants of the indoor conditions: Temperature, Relative Humidity, and CO2 levels in the classrooms. The novelty of this study is that it evaluated the influence of engaging teachers in the management of their working indoor environments. This paper presents the results of the perceived health, comfort, and well-being of teachers from two primary schools built before 1919 located in Edinburgh, Scotland. Visual feedback sensors improved the perceived air quality of teachers in their classrooms but increased pressure on their workload and were a potential distraction for their pupils. In contrast, raising the awareness of the teachers via the webinar improved their perception of their indoor environment without added pressure. Therefore, awareness programs should be devised to educate school staff on Indoor Air Quality in addition to the development of sensors with visual feedback.

Gold nanoclusters-based CO2 sensor and their application in sparkling water

Gold nanoclusters-based CO2 sensor and their application in sparkling water

Gas Adsorption on the Co2Te3 Monolayer: Density Functional Theory Study.

We report a numerical investigation of the chemical adsorption of acetone and carbon dioxide gases by a cobalt telluride (III) 2D layer. Calculations were performed using first principles calculations within the density functional theory to evaluate the adsorbed gas impact on the material's conductivity. The adsorption of carbon dioxide was found to significantly affect the Co2Te3 monolayer electronic structure and its electrical conductivity, which is not observed in the case of acetone. This letter demonstrates that the calculated bond formation energy for carbon dioxide is approximately 2 times higher than that for the acetone. It proved that the quasi-2D cobalt telluride (III) could be introduced as a selective electrochemical sensor for carbon dioxide in quick medical diagnoses and other technological applications.

Evaluation of B-Site Doped Barium Niobate Perovskite Anodes for the Electrochemical Oxidative Coupling of Methane

More efficient usage of shale gas reserves and natural gas resources will allow for higher olefin yields and lower greenhouse gas emissions. The oxidative coupling of methane (OCM) is a direct pathway for converting methane to ethylene at temperatures >700 °C. OCM catalysts preferably avoid COx products and limit coke formation on the catalyst. Often, catalysts are analyzed via computationally expensive DFT computations in combination with experimental results leading to long lead times for catalyst development. Perovskite oxide catalysts are useful for OCM due to their flexible bond networks and varied properties (conductivity, selectivity, surface area) based on synthesis/doping. This work aims to illustrate the utility of the bond-valence bond-length model (ionic model)1 ,2 in conjunction with gas reduction experiments for rapid structure evaluation of the co-doped perovskite BaMg0.33Nb0.67-xFexO3-δ (BMNF, x=0.17,0.25,0.33). This perovskite catalyst has previously been adopted as a CO2 sensing material3 and an active/stable anode for the electrochemical oxidative coupling of methane4 (E-OCM). Further evaluation of this perovskite by our group illustrated the unique stability of ionic Fe into the BMNF while performing the oxidative coupling of methane5. This work delves into the crystal structure of the BMNF material as well as its chemical stability validated using a much more facile computational methodology featuring the bond-valence bond-length method. XPS, XRD, and reduction/oxidation high temperature cycling are utilized in conjunction to illustrate the stabilizing mechanisms for cations within the BMNF perovskite when exposed to highly reducing environments. References (1) Pauling, L. "The principles determining the structure of complex ionic crystals."J. Am. Chem. Soc. 1929, 51 1010-1026.(2) Lufaso, M. W.; Woodward, P. M. Prediction of the Crystal Structures of Perovskites Using the Software Program SPuDS. Acta Crystallogr. B 2001, 57 (6), 725–738. https://doi.org/10.1107/S0108768101015282.(3) Kannan, R.; Mulmi, S.; Thangadurai, V. Synthesis and Characterization of Perovskite-Type BaMg0.33Nb0.67−xFexO3−δ for Potential High Temperature CO2 Sensors Application. J. Mater. Chem. A 2013, 1 (23), 6874–6879. https://doi.org/10.1039/C3TA10572E.(4) Denoyer, L. H.; Benavidez, A.; Garzon, F. H.; Ramaiyan, K. P. Highly Stable Doped Barium Niobate Based Electrocatalysts for Effective Electrochemical Coupling of Methane to Ethylene. Adv. Mater. Interfaces 2022, 9 (27), 2200796. https://doi.org/10.1002/admi.202200796.(5) Denoyer, L. H.; Benavidez, A.; Garzon, F. H.; Electrochemical oxidative coupling of methane: deciphering the exceptional properties of BaMg0.33Nb0.67-xFexO3-δ for enhanced electrocatalysis and durable operation. Accepted by Energy & Fuels Feb. 2024

Optimizing Sensitivity of Room Temperature CO2 Sensors through Co-Doped ZnO Nanorods By Magnetron Sputtering System

Metal oxide semiconductors (MOS) based gas sensors have been identified as a promising solution for future applications due to their exceptional electrochemical, physical, and gas sensing properties. Due to their excellent optical and electrical features, ZnO nanostructures have become increasingly popular for gas detection applications, mainly because of their abundant availability. Despite its potential, the ZnO-based sensors have challenges such as poor selectivity and high power consumption at elevated operating temperatures. Transition metal doping, for example with cobalt depicted decent promising results in high response and selectivity of ZnO nanomaterials towards certain gasses. This study investigates the sensitivity enhancement of room temperature CO2 sensors utilizing the cobalt-doped ZnO (CZO) nanorod architecture. The CZO thin films were deposited on glass substrates using radio frequency (RF) magnetron sputtering at varying powers. Structural, morphological, and gas response properties of the CZO thin films were analyzed.Figure 1 illustrates the evolution of resistance over time for CZO sensors when exposed to CO2 gas concentrations ranging from 1 to 500 ppm at room temperature in dry air. In this investigation, the response to gas follows a consistent linear pattern within the 1−300 ppm range. However, as the concentration rises, a noticeable deviation towards nonlinearity becomes more pronounced. The sensor exhibits a heightened response across various concentration levels: 1 (8.9), 50 (12.5), 100 (14.79), 150 (15.7), 250 (18.82), and 500 (23.52) ppm. Discrepancies in the sensor response are attributed to the distinct surface morphology inherent to each sensor type. The introduction of co-doping enhances the occurrence of point defects and oxygen vacancies within the CZO sensors. The Scanning Electron Microscopy (SEM) images reveal that the CZO material exhibits a highly organized surface morphology, characterized by densely packed spherical structures, and the cross-sectional analysis of the material shows a uniform thickness of 136 nm, indicating its potential applications in the field of sensing and detection, shown in figure 2. This study underscores the effectiveness of CZO nanorod architecture in rapidly detecting CO2 at room temperature, presenting promising avenues for environmental monitoring and sensing applications Figure 1