Ppm Acetone Research Articles

Tin oxide nanoparticles anchored on ordered mesoporous carbon for efficient acetone sensing

Rationally designed combinations of semiconductor metal oxides (SMO) and carbon materials can lead to the development of sensing materials with excellent gas performance. Herein, SnO2 nanoparticles (NPs) decorated on ordered mesoporous carbon (CMK-3) nanorods were synthetized by solvothermal and high-temperature calcination methods. Various characterization and gas sensing tests indicated that the resulting one-dimensional (1D) self-assembled SnO2@CMK-3 composite had a large specific surface area (88.02 m2/g) and excellent gas sensing performance. Specifically, at optimal working temperature, the as-prepared SnO2@CMK-3 sensor had a high response (122.1), low limit of detection, good linear fitting (R2 = 0.9892), rapid response/recovery time (5/27 s) towards 50 ppm acetone. Meanwhile, by detecting six gases, including acetone, ammonia, formaldehyde, xylene, triethylamine, and ethanol, it was found that the SnO2@CMK-3 sensor showed good selectivity to acetone. The unique nanostructure, large specific surface area, high oxygen vacancy content, and the formation of heterojunctions accounted for the good performance to acetone. These results highlighted the potential application of the SnO2@CMK-3 composite for the detection of acetone gas and presented a promising approach to prepare SMO@carbon composites for VOCs detection.

The Jahn–Teller distortion‐induced electronic structure regulation of Mn‐doped Co3O4 for enhanced acetone detection

AbstractThe modulation of the electronic structure of metal oxides is crucial to enhance their gas‐sensing performance. However, there is lacking in profound study on the effect of electronic structure regulation on sensing performance. Herein, we propose an innovative strategy of Jahn–Teller distortion‐induced electronic configuration regulation of Co3O4 to improve acetone sensing performance. After the introduction of Mn3+ into Co3O4 (Mn‐Co3O4), the Jahn–Teller distortion of high‐spin Mn3+ (t2g3eg1) conversed to low‐spin Mn4+ (t2g3eg0), resulting in conversion of Co3+ (t2g6eg0) into Co2+ (t2g6eg1). As expected, Mn‐Co3O4 exhibits a high response value of 46.7 toward 100 ppm acetone, low limit of detection of 0.75 ppb, high selectivity, and high stability, which are overwhelmingly superior to previous Co3O4‐based acetone sensors. The dynamics and thermodynamics analysis demonstrate that the Mn doping improves sensing reaction rate, reduces reaction barrier, and promotes the charge transfer. The theoretical calculations further prove the charge transfer from Mn to Co derived from Jahn–Teller distortion and support promoting the adsorption of acetone on Co3O4 by Mn dopant. Moreover, we demonstrated the substantial potential application of Mn‐Co3O4 sensor as a monitoring gas sensor in pest resistance of Arabidopsis. This work provides a new strategy to design sensing materials from electronic configuration perspective.image

Perovskite-structured LaFeO3 gas sensor modified by polyoxometalate electron acceptor with high sensitivity and low detection limit for acetone gas☆

Lanthanum ferrite is a representative perovskite-structured rare earth-based bimetallic oxide, which has been widely studied in magnetic materials, sensors, catalysts and batteries. Herein, we designed and prepared polyoxometalate electron acceptor decorated LaFeO3 gas-sensitive composite materials with one-dimensional nanoribbons morphology by electrospinning. The effects of different mass fraction of Keggin type phosphotungstic acid (PW12) on the gas-sensitive properties of LaFeO3 nanoribbons were investigated. The results show that the response value of LaFeO3/PW12 sensor to acetone gas first increases and then decreases with the increase of PW12 content. The LaFeO3/3%PW12 sensor exhibits a maximum response of 3.35 to 5 ppm acetone at 250 °C, a 2.6 times increase in response value and a 90 °C reduction in operating temperature compared to pure LaFeO3 nanoribbons. The LaFeO3/3%PW12 sensor exhibits good linear relation in ppb-level concentrations and the lowest detection concentration is 100 ppb. The sensors also show good repeatability in 6 tests and excellent long-term stability in 30 d. The improvement of the gas sensitive properties of the composite can be attributed to the synergistic effect between the two components. As an electron acceptor, PW12 promotes carrier migration between PW12 and LaFeO3, thereby improving the gas sensing performance of LaFeO3. This work promotes the practical application of polyoxometalate to promote rare earth-based gas sensitive materials in sensing field.

Acetone Gas Sensor with SnO2-Modified MoS2 Nanospheres

This study employed a hydrothermal method to prepare molybdenum disulfide (MoS2) and a two-step hydrothermal process to synthesize tin oxide (SnO2)-modified MoS2 nanostructured materials. The manufacturing process is simple and cost-effective, and the produced materials were analyzed using various techniques to confirm their high purity and crystallinity. The SnO2-modified MoS2 nanostructured materials were then utilized to fabricate acetone gas sensors. The high surface area of MoS2, coupled with the heterojunction interfaces formed by SnO2 modification, enhances the performance of the gas sensor. At 150 °C, the sensor exhibits a remarkable response of 37.1% to 100 ppm acetone gas. The dynamic response, including response and recovery times, is also impressive. Gas sensors developed with this material can effectively detect acetone concentrations in various environmental conditions.

Temperature-modulated acetone monitoring using Al2O3-coated evanescent wave fiber optic sensors

This paper presents an experimental study of a fiber-optic-based acetone sensor and its temperature effects for use as a breath analyzer to detect acetone in exhaled breath. The study employs fiber optic evanescent wave-based acetone sensing, utilizing sputter coated Aluminium Oxide (Al2O3)-coated probes fabricated via clad modification technique. The optical fibers were coated with Al2O3 to achieve thicknesses of 247.03 nm, 334.05 nm, and 468.75 nm. The sensor probes were characterized using, Field Emission Scanning Electron Microscopy (FESEM), Energy Dispersive Spectroscopy (EDS), X-ray Diffraction (XRD), Ultraviolet-Visible (UV-Vis) Spectroscopy, and Spectroscopic Ellipsometry for uniformity, elemental, optical constants, and thickness of the Al2O3. The spectral responses of the probes were analyzed for acetone concentrations ranging from 0 to 100 ppm, with temperature modulation from room temperature to 100 °C. The probe with a ∼334 nm thick Al2O3 coating exhibited the highest response, reaching 6.2 % at 100 °C in 100 ppm acetone. Linear regression revealed that the ∼334 nm coated probe had the highest sensitivity at 5.98 counts/ppm. The sensor showed response and recovery times of approximately 12 and 17 seconds, respectively. This study underscores the stability and repeatability of temperature-modulated Al2O3-coated fiber optic sensors for selective acetone detection in various non-invasive applications.

Hollow CuO/Cu2O octahedrons for selective and stable detection of acetone gas

Acetone (C3H6O) is key member of the volatile organic compound family, which can cause health as well as environmental issues. The identification and sensing of acetone gas are important in many applications such as air quality control and biomarker-based diagnosis. Here, we synthesized hollow CuO/Cu2O octahedrons heterostructure composite through coprecipitation and subsequent heat treatment. The sensor manifested a response of 3.52–50 ppm acetone gas at 350 °C. Besides, it showed excellent stability in a 150-day test and excellent repeatability, with a response of 4.15. Also, exhaled gas sensing was carried out using standard method to estimate the acetone concentration in breath. The high sensing capability of the sensor was ascribed to the formation of p-p heterojunctions, the hollow morphology of octahedrons, and the presence of structural defects. The hollow CuO/Cu2O octahedron sensor with good performance may be employed for the detection and monitoring of acetone gas in real situations.

Enhancing acetone detection of In2O3-decorated MOF-derived Fe2O3 spindles with Pt nanoparticles functionalization

Designsensing materials with core-shell structure is an excellent strategy to achieve high sensing performance toward acetone detection. Herein, MIL-88A(Fe) was fabricated via a hydrothermal route, which renders as a template to fabricate Fe2O3@In2O3 core-shell spindles structure. Gas sensing results show that the sensor based on Fe2O3@In2O3 exhibit enhanced response of 193–200 ppm acetone than that of 36 for pristine Fe2O3 at 200 °C. After Pt functionalization, the response of Fe2O3@In2O3/Pt to 200 ppm acetone is up to 839 at a reducing working temperature of 180 °C with a good selectivity and long-term stability. A synergistic mechanism originated from the intrinsic merits of Fe2O3 and In2O3, the 1D core-shell structure, the creation of heterojunction at the interface of Fe2O3 and In2O3 and the creation of Shottky junction at In2O3 and Pt nanoparticles, and the catalytic reaction of Pt holds accountable for the significant improvement in acetone sensing.

Bacterial cellulose/polyethylene glycol composite aerogel with incorporated graphene and metal oxides for VOCs detection

It is important to monitor and detect volatile organic compounds (VOCs) for environmental protection, occupational safety and human health. Portable and compact VOC sensing devices with a fast response are needed for real-time monitoring and simple analysis. Using solvent exchange and freeze-drying techniques, an ultralight 3D bacterial cellulose (BC) aerogel is prepared and modified by polyethylene glycol with the functionalization of graphene and metal oxides to detect VOC gases. Unlike commercially available flat VOC sensors, the 3D structure of our VOC sensor with high permeability of BC composite provides superior sensing characteristics for acetone, formaldehyde and ethanol in a wider range of scenarios. The portable BC composite sensor exhibits remarkable sensitivity and selectivity toward VOCs detection. The BC composite with TiO2 has a response time of about 20 s to 1 ppm acetone and can detect as low as 1.43 ppm at room temperature. In addition, BC composites with ZnO are suitable for detecting formaldehyde in indoor air.

Nitrogen-Doped Carbon Quantum Dots Activated Dandelion-Like Hierarchical WO3 for Highly Sensitive and Selective MEMS Sensors in Diabetes Detection.

High sensitivity, low concentration, and excellent selectivity are pronounced primary challenges for semiconductor gas sensors to monitor acetone from exhaled breath. In this study, nitrogen-doped carbon quantum dots (N-CQDs) with high reactivity were used to activate dandelion-like hierarchical tungsten oxide (WO3) microspheres to construct an efficient and stable acetone gas sensor. Benefiting from the synergistic effect of both the abundant active sites provided by the unique dandelion-like hierarchical structure and the high reaction potential generated by the sensitization of the N-CQDs, the resulting 16 wt % N-CQDs/WO3 sensor shows an ultrahigh response value (Ra/Rg = 74@1 ppm acetone), low detection limit (0.05 ppm), outstanding selectivity, and reliable stability to acetone at the optimum working temperature of 210 °C. Noteworthy that the N-CQDs facilitate the carrier migration and intensify the reaction between acetone and WO3 during the sensing process. Considering the above advantages, N-CQDs as a sensitizer to achieve excellent gas-sensitive properties of WO3 are a promising new strategy for achieving accurate acetone detection in real time and facilitating the development of portable human-exhaled gas sensors.

Synthesis of Pd-decorated ZnO nanocomposites with improved gas-sensitive properties for acetone detection

ZnO/Pd nanocomposites containing 0.5–3.0 mol.% palladium and possessing improved gas-sensitive properties for VOC’s detection were prepared using solvothermal synthesis. The synthesised powders have been characterised using various methods of physicochemical analysis (DSC/TGA, XRD, SET/TEM, XPS). It is shown that Pd@PdO nanoparticles (4–7 nm in diameter) are localised on the surface of ZnO nanoparticles (40–50 nm in size). According to the combined XRD and XPS data, it was found that palladium is in partially oxidised state, and the nanocomposite has a structure close to "core@shell": Pd@PdO. The influence of palladium concentration in the ZnO/Pd composite on the complex of chemoresistive gas-sensitive properties was studied. It is shown that at 250 °C the obtained nanocomposites demonstrate a high (up to 57.8 a.u.) response to 100 ppb–20 ppm acetone, which can be used as a part of supersensitive devices for noninvasive diagnostics of diseases.

Shape controlled synthesis and crystal facet dependent gas sensitivity of tungsten oxide

Gas sensors can achieve remarkable functionality through the optimization of particle size, shapes, crystal facets, and oxygen defects, resulting in unsaturated coordination atoms, high charge densities, and enhanced bond energies. In this study, WO2.72 nanourchins, WO3-x nanowires, and WO3 nanorods/nanocube with (010), (001), (200), and (002) dominant crystal facets were synthesized and used as gas sensing materials. It was found that WO2.72 nanourchins exhibit an excellent response of Ra/Rg=21 to 100 ppm acetone with good selectivity among other sensors as-fabricated. First-principle calculations of Density Functional Theory were performed on acetone's adsorption on different crystal planes of tungsten oxide. The results verify spontaneous and fast adsorption on the (010) crystal plane than on the (001) and (200) planes. Further characterizations indicate that WO2.72 nanourchins with (010) crystal facets contain more reactive sites with high surface energy, facilitating charge separation, increasing charge carrier mobility, and enabling the redox reactions to occur independently at different rates. Moreover, their richer electron-donor surface oxygen defects, smaller feature sizes, and higher surface area (SBET) with hierarchical porous structures, all contribute to the enhanced acetone sensing. Our work provides a strategy for improved acetone sensing based on optimizing the particle shape with different crystal facets and oxygen vacancy density. We further expect our strategy to be applicable in designing other sensor materials with efficient charge separation and fast surface redox reactions to detect toxic gases.

UV-assisted fluctuation-enhanced gas sensing by ink-printed MoS2 devices

In this work, MoS2 flakes were printed on ceramic substrates and investigated toward 1–10 ppm of nitrogen dioxide (NO2), 2–12 ppm of ammonia (NH3), and 2–12 ppm acetone (C3H6O) under UV light (275 nm). The structure of overlapping MoS2 flakes and UV light assistance affected high responsivity to NO2 when DC resistance was monitored, and superior sensitivity to NH3 was obtained from the low-frequency noise spectra. MoS2 exhibited response and recovery times in hundreds of seconds and stability throughout the experiments conducted within a few months. MoS2 sensor exhibited a resistance drift during the detection of a specific relaxation time. Subtracting the baseline burden with exponential drift exposed the direction of changes induced by oxidizing and reducing gases and reduced DL to 80 ppb, 130 ppb, and 360 ppb for NO2, NH3, and C3H6O, respectively. The fluctuation-enhanced sensing (FES) revealed that the adsorption of NO2 on MoS2 decreases the noise intensity, whereas adsorbed NH3 increases the fluctuations of current flowing through the sensor, and these changes are proportional to the concentration of gases. The noise responses for NO2 and NH3 were opposite and higher than DC resistance responses with subtracted baseline (an increase of 50% for 10 ppm of NO2 and an increase of more than 600% for 12 ppm of NH3), showing that FES is a highly sensitive tool to detect and distinguish between these two gases. This way, we introduce a simple and low-cost method of gas sensor fabrication using ink-printed MoS2 and the possibility of enhancing its sensitivity through data processing and the FES method.

Operation Temperature Effects on a Microwave Gas Sensor with and without Sensitive Material.

Microwave gas sensors have garnered attention for their high sensitivity and selectivity in the detection of volatile organic compounds (VOCs). However, traditional gas sensors generally rely on sensitive materials that degrade over time and are easily affected by the environment, compromising their stability and accuracy. This study proposes a microwave VOC gas sensor based on the condensation effect. The sensor adopts a novel design without sensitive materials, utilizing the condensation effect to detect acetone gas. The sensor system consists of a microwave sensor and a temperature control device. As the sensor temperature is lowered below the boiling point of acetone, the condensation of acetone gas on the sensor surface is achieved, enabling accurate detection of acetone gas. Experimental results indicate that the accumulated amount of acetone on the sensor surface is positively correlated with its response, with the maximum response of 3000 ppm acetone gas reaching 0.34 dB. Additionally, this study investigated the detection mechanism of the sensor after adding the sensitive material MXene and compared the performance of the sensor at different temperatures (-10 °C, 0 °C, and 60 °C). The results show that at -10 °C the sensor mainly captures acetone through physical adsorption, while at 25 and 60 °C, it primarily responds through chemical adsorption, with a maximum response of 0.29 dB. The VOC sensor based on the condensation effect without sensitive materials not only achieves the same sensitivity as traditional microwave sensors but also demonstrates stronger stability and anti-interference capabilities.

Construction of a novel Mott-Schottky heterostructure gas sensor g-C3N4/SnO2 with layered nanorods array for high-sensitivity acetone detection

Developing exhaled acetone sensors with high performance can be effectively applied to the medical diagnosis and the health monitoring. Herein, a two-dimensional (2D) layered graphitic carbon nitride (g-C3N4) with tunable electronic structure, abundant edge sites, and high stability is proposed, and it is further coupled with stannic oxide (SnO2) by one-step hydrothermal approach to construct a Mott-Schottky heterostructure with layered nanorods array. The exceptional response of the as-fabricated g-C3N4/SnO2 gas sensor to 50 ppm acetone at 100 °C is four times higher than that of the pristine SnO2 sensor. Additionally, the g-C3N4/SnO2 sensor's remarkable selectivity, long-term stability against acetone gas, and detection limit of 250 ppb are exhibited. The unique hierarchical design and the Mott-Schottky heterostructure creation which validated by electrochemical study, may be in charge of the enhanced acetone sensing capabilities of g-C3N4/SnO2 gas sensor. This work will provide a concise and effective avenue to construct hierarchical composite with Mott-Schottky heterostructure for high-performance acetone gas sensor.

Deep-Learning-Based Blood Glucose Detection Device Using Acetone Exhaled Breath Sensing Features of α-Fe2O3-MWCNT Nanocomposites.

Owing to the correlation between acetone in human's exhaled breath (EB) and blood glucose, the development of EB acetone gas-sensing devices is important for early diagnosis of diabetes diseases. In this article, a noninvasive blood glucose detection device through acetone sensing in EB, based on an α-Fe2O3-multiwalled carbon nanotube (MWCNT) nanocomposite, was successfully developed. Different amounts of α-Fe2O3 were added to the MWCNTs by a simple solution method. The optimized acetone gas sensor showed a response of 5.15 to 10 ppm acetone gas at 200 °C. Also, the fabricated sensor showed very good sensing properties even in an atmosphere with high relative humidity. Since the EB has high humidity, the proposed sensor is a promising device to exactly detect the amount of acetone in EB with high humidity. The sensor was powered by a 3200 mAh battery with the possibility of charging using mains electricity. To increase the reliability and calibration of the sensing device, a practical test was taken to detect acetone EB from 50 volunteers, and a deep learning algorithm (DLA) was used to detect the effect of various factors on the amount of acetone in each person's acetone EB. The proposed device with ±15 errors had almost 85% correct responses. Also, the proposed device had excellent response, short response time, good selectivity, and good repeatability, leading it to be a suitable candidate for noninvasive blood glucose sensing.

Artificial Intelligence‐Enhanced “Photonic Nose” for Mid‐Infrared Spectroscopic Analysis of Trace Volatile Organic Compound Mixtures

AbstractMolecular identification of volatile organic compounds (VOCs) plays an important role in various applications including environmental monitoring and smart farming. Mid‐infrared (MIR) fingerprint absorption spectroscopy is a powerful tool to extract chemical‐specific features for gas identification. However, the detection and recognition of trace VOC gas mixtures remain challenging due to their intrinsic weak light–matter interaction and highly overlapped absorption spectra. Here, an artificial intelligence‐enhanced “photonic nose” for MIR spectroscopic analysis of trace VOC gas mixtures is proposed. To enhance the sensing performance by increasing bandwidth and sensitivity, the “photonic nose” is designed to employ coupled multi‐resonant plasmonic nanoantennas to cover MIR molecular fingerprints, coated with metal–organic frameworks as the gas enrichment layer. Low limits of detection are achieved (IPA: 1.99 ppm, ethanol: 3.43 ppm, and acetone: 9.82 ppm). With machine learning, a high classification accuracy of 100% is realized for 125 mixing ratios (IPA, ethanol: both 5 concentrations, 0–130 ppm; acetone: 5 concentrations, 0–201 ppm), and low‐deviation component concentration predictions of root‐mean‐squared error within 10 ppm are achieved for IPA and ethanol (both 0–130 ppm) under interference from 50 ppm acetone. The work paves the way for intelligent sensing platforms for environmental monitoring and smart framing.

Unlocking Co3O4–ZnO p-n heterojunction for superior acetone gas sensing detection

In this study, we synthesized pure ZnO and Co3O4–ZnO precursors with varied Co, Zn ratios via solvothermal method, and then the precursors were calcined at 400 ​°C for 2 ​h in a muffle furnace under air to obtain composites for acetone detection. The structure, morphology, elemental composition, microstructure and chemical state of these materials were systematically studied by various characterization techniques. Additionally, we also evaluated the gas sensing performance of the composites-based sensors, focusing on optimal operating temperature, baseline resistance, repeatability, stability, selectivity, response/recovery time, and resistance under varying relative humidity. The findings reveal that 3 ​% Co3O4–ZnO-based sensor exhibit the highest response value to 100 ​ppm acetone (74), showing an enhancement of approximately 9.3 times compared to the pure ZnO-based sensor (8). Furthermore, the 3 ​% Co3O4–ZnO-based sensor demonstrate the advantages of rapid response/recovery times (15 ​s/2 ​s), outstanding selectivity, and remarkable stability. The gas sensing mechanism of the composite material is also discussed in detail, which provides insights into the observed enhancement of gas sensing performance. It provides an idea for the follow-up study on gas sensing performance of acetone sensors.

Efficient mixed-potential acetone sensor with yttria-stabilized zirconia and porous Co3O4 nanofoam sensing electrode for hazardous gas monitoring and breath analysis

For hazardous gas monitoring and non-invasive diagnosis of diabetes using breath analysis, porous foams assembled by Co3O4 nanoparticles were designed as sensing electrode materials to fabricate efficient yttria-stabilized zirconia (YSZ)-based acetone sensors. The sensitivity of the sensors was improved by varying the sintering temperature to regulate the morphology. Compared to other materials sintered at different temperatures, the porous Co3O4 nanofoams sintered at 800 °C exhibited the highest electrochemical catalytic activity during the electrochemical test. The response of the corresponding Co3O4-based sensor to 10 ppm acetone was –77.2 mV and it exhibited fast response and recovery times. Moreover, the fabricated sensor achieved a low detection limit of 0.05 ppm and a high sensitivity of –56 mV/decade in the acetone concentration range of 1–20 ppm. The sensor also exhibited excellent repeatability, acceptable selectivity, good O2/humidity resistance, and long-term stability during continuous measurements for over 30 days. Moreover, the fabricated sensor was used to determine the acetone concentration in the exhaled breaths of patients with diabetic ketosis. The results indicated that it could distinguish between healthy individuals and patients with diabetic ketosis, thereby proving its abilities to diagnose and monitor diabetic ketosis. Based on its excellent sensitivity and exhaled breath measurement results, the developed sensor has broad application prospects.

Innovative Wearable Sweat Sensor Array for Real-Time Volatile Organic Compound Detection in Noninvasive Diabetes Monitoring.

Wearable sweat sensors are reshaping healthcare monitoring, providing real-time data on hydration and electrolyte levels with user-friendly, noninvasive devices. This paper introduces a highly portable two-channel microfluidic device for simultaneous sweat sampling and the real-time detection of volatile organic compound (VOC) biomarkers. This innovative wearable microfluidic system is tailored for monitoring diabetes through the continuous and noninvasive tracking of acetone and ammonia VOCs, and it seamlessly integrates with smartphones for easy data management. The core of this system lies in the utilization of carbon polymer dots (CPDs) and carbon dots (CDs) derived from monomers such as catechol, resorcinol, o-phenylenediamine, urea, and citric acid. These dots are seamlessly integrated into hydrogels made from gelatin and poly(vinyl alcohol), resulting in an advanced solid-state fluorometric sensor coating on a cellulose paper substrate. These sensors exhibit exceptional performance, offering linear detection ranges of 0.05-0.15 ppm for acetone and 0.25-0.37 ppm for ammonia, with notably low detection limits of 0.01 and 0.08 ppm, respectively. Rigorous optimization of operational parameters, encompassing the temperature, sample volume, and assay time, has been undertaken to maximize device performance. Furthermore, these sensors demonstrate impressive selectivity, effectively discerning between biologically similar substances and other potential compounds commonly present in sweat. As this field matures, the prospect of cost-effective, continuous, personalized health monitoring through wearable VOC sensors holds significant potential for overcoming barriers to comprehensive medical care in underserved regions. This highlights the transformative capacity of wearable VOC sweat sensing in ensuring equitable access to advanced healthcare diagnostics, particularly in remote or geographically isolated areas.

Study on the acetone adsorption mechanism of In2O3/SnO2 heterocomposite fibers

A heterocomposite structure offers significant advantages for enhancing the gas sensing performance of metal oxide-based sensors. In this study, In2O3/SnO2 heterocomposite fibers were fabricated by electrospinning. In2O3/SnO2 heterocomposite fibers show excellent gas sensing performance for acetone. The response of the In2O3/SnO2 sensor is 9.3–100 ppm acetone, markedly outperforming sensors made solely of SnO2 or In2O3. To clarify the improved mechanism, the adsorption behavior of In2O3/SnO2 for acetone was studied based on Density Functional Theory (DFT). The adsorption energy of In2O3/SnO2 for acetone at the optimal adsorption site is 0.89 |eV|, which is 0.18 |eV| and 0.04 |eV| higher than that of SnO2 and In2O3, respectively. Additionally, the electron transfer numbers of acetone to In2O3/SnO2 are also 0.08|e| and 0.05|e| greater than those of SnO2 and In2O3, respectively. The n-n heterojunction of In2O3/SnO2 alters the material's barrier, significantly enhancing carrier concentration and electron transfer. This n-n heterojunction is key to the improved gas sensing performance of the In2O3/SnO2 sensor for acetone. Therefore, In2O3/SnO2 heterocomposite fibers have great application potential in the field of gas sensors.