Study on the Inhibition Mechanism of Hydration Expansion of Yunnan Gas Shale using Modified Asphalt.

Drilling fluids play an essential role in shale gas development. It is not possible to scale up the use of water-based drilling fluid in shale gas drilling in Yunnan, China, because conventional inhibitors cannot effectively inhibit the hydration of the illite-rich shale formed. In this study, the inhibition performance of modified asphalt was evaluated using the plugging test, expansion test, shale recovery experiment, and rock compressive strength test. The experimental results show that in a 3% modified asphalt solution, the expansion of shale is reduced by 56.3%, the recovery is as high as 97.8%, water absorption is reduced by 24.3%, and the compression resistance is doubled compared with those in water. Moreover, the modified asphalt can effectively reduce the fluid loss of the drilling fluid. Modified asphalt can form a hydrophobic membrane through a large amount of adsorption on the shale surface, consequently inhibiting shale hydration. Simultaneously, modified asphalt can reduce the entrance of water into the shale through blocking pores, micro-cracks, and cracks and further inhibit the hydration expansion of shale. This demonstrates that modified asphalt will be an ideal choice for drilling shale gas formations in Yunnan through water-based drilling fluids.

CuCo2O4 nanoneedle arrays growth on carbon cloth as a non-enzymatic electrochemical sensor with low detection limit ketoprofen recognition.

An electrochemical sensor for detecting ketoprofen was constructed by in-situ grown copper cobaltate (CuCo2O4) nanoneedle arrays on a carbon cloth (CC) substrate. The resulting porous nanoneedle arrays not only expose numerous electrochemically active sites but also significantly enhance the electrochemical apparent active area and current transmission efficiency. By leveraging its electrochemical properties, the sensor achieves an impressive detection limit for ketoprofen of 0.7 pM, with a linear range spanning from 2 pM ~ 2 µM. Furthermore, the sensor exhibits remarkable reproducibility, anti-interference capabilities, and stability. Notably, the developed sensor also performed ketoprofen detection on real samples (including drug formulations and wastewater) and demonstrated excellent recognition ability. These exceptional performances can be attributed to the direct growth of CuCo2O4 nanoneedle arrays on the CC substrate, which facilitates a robust electrical connection, provides abundant electrocatalytic active sites, and expands the apparent active area. Consequently, these improvements contribute to the efficient trace detection capabilities of the ketoprofen sensor.

Synergy of Active Sites and Charge Transfer in Branched WO3/W18O49 Heterostructures for Enhanced NO2 Sensing.

Achieving reliable detection of trace levels of NO2 gas is essential for environmental monitoring and protection of human health protection. Herein, a thin-film gas sensor based on branched WO3/W18O49 heterostructures was fabricated. The optimized WO3/W18O49 sensor exhibited outstanding NO2 sensing properties with an ultrahigh response value (1038) and low detection limit (10 ppb) at 50 °C. Such excellent sensing performance could be ascribed to the synergistic effect of accelerated charge transfer and increased active sites, which is confirmed by electrochemical impedance spectroscopy and temperature-programmed desorption characterization. The sensor exhibited an excellent detection ability to NO2 under different air quality conditions. This work provides an effective strategy for constructing WO3/W18O49 heterostructures for developing NO2 gas sensors with an excellent sensing performance.

Novel Modified Styrene-Based Microspheres for Enhancing the Performance of Drilling Fluids at High Temperatures.

Ensuring wellbore stability is of utmost importance for safety when drilling in deep formations. However, high temperatures severely disrupt the drilling fluid gel system, leading to severe stability issues within ultra-deep formations containing micropores. This study focused on the development of a polymer-based plugging material capable of withstanding high temperatures up to 200 °C. A kind of microsphere, referred to as SST (styrene-sodium styrene sulfonate copolymer), was synthesized with a particle size of 322 nm. Compared to polystyrene, the thermal stability of SST is greatly improved, with a thermal decomposition temperature of 362 °C. Even after subjecting SST to hot rolling at 200 °C for 16 h, the particle size, elemental composition, and zeta potential remained stable within an aqueous dispersion system. The results of core displacement and NMR tests demonstrate that SST considerably reduces the pore diameter with a remarkable plugging efficiency of 78.9%. Additionally, when drilling fluids reach 200 °C, SST still enhances drilling fluid suspension and dispersion, and reduces fluid loss by over 36% by facilitating the dispersion of clay particles, improving the gel structure of the drilling fluid, resisting clay dehydration, and promoting plugging. The development of SST provides valuable insights into the preparation of high-temperature-resistant microspheres and the formulation of effective plugging agents for deep-well drilling fluids.

A Novel Amphoteric Ion-Modified, Styrene-Based Nano-Microsphere and Its Application in Drilling Fluid.

With the gradual depletion of shallow oil and gas, deep oil and gas has become the focus of development. However, deep formations generally face the challenge of high-temperature and high-salinity, and drilling fluid agents are prone to failure, leading to drilling fluid intrusion into the formation that can cause serious drilling accidents such as well bore collapse. For this, a styrene-based nano-microsphere (SSD) modified with amphoteric ions was developed, with a particle size of 228 nm which could resist temperatures up to 200 °C and sodium chloride (NaCl) up to saturation. SSD has significant salt-responsive properties and its aqueous dispersion becomes transparent with increasing salinity. The SSD provided superior plugging performance in solutions containing NaCl, with a core plugging efficiency of 95.2%, and it was significantly better than the anion-modified microspheres. In addition, in drilling fluids under high temperature and high-salinity conditions, the SSD promotes particle gradation of drilling fluids and improves the zeta potential through its own plugging and synergistic effect with clay, which significantly improves the comprehensive performance of drilling fluids, such as stability, rheological performance, and filtration reduction performance. The development of SSD provides a new idea for research of high-temperature and high-salinity-resistant drilling fluid agents.

Bulk Passivation Enables Hundredfold-Enhanced Electroluminescence of Monophosphine Cu4 I4 Cubes.

Electroluminescent (EL) clusters emerged rapidly, owing to their organic-inorganic hybrid character useful for comprehensive performance integration and the potential for large-scale display and lighting applications. However, despite their good photoluminescent (PL) properties, until present, no efficient EL monodentate ligand-based clusters were reported due to structural variation during processing and excitation and exciton confinement on cluster-centered quenching states. Here we demonstrate an effective bulky passivation strategy for efficient cluster light-emitting diodes with a monophosphine Cu4 I4 cube named [TMeOPP]4 Cu4 I4 . With terminal pyridine groups, an active matrix named TmPyPB supports an effective host-cluster interplay for configuration fixation, structural stabilization, and exciton-confinement optimization. Compared to common inactive hosts, the passivation effects of TmPyPB markedly reduce trap-state densities by 24-40 % to suppress nonradiative decay, resulting in state-of-the-art PL and EL quantum yields reaching 99 % and 15.6 %, respectively, which are significantly improved by about 7-fold. TmPyPB simultaneously increases EL luminance to 104 nits, which is ≈100-fold that of the non-doped analogue.

Solvent-directed multiple correspondence fluorescent probe for highly selective and sensitive detection of Cu2+ and Mg2.

A solvent-directed, new Schiff base multiple correspondence fluorescent probe, (E)-2-(2-hydroxybenzylidene) hydrazine-1-carboxamid (L), was synthesized for selective sensing of Cu2+ and Mg2+ ions. L showed excellent selectivity and high sensitivity toward Cu2+ in "turn off" mode with a detection limit of 40.5 nM in 10 mM, pH = 7.0 PBS buffer. Contrary to that, when acetonitrile was used as the solvent, L exhibited highly selective and sensitive fluorescence sensing ability for Mg2+ in "turn on" mode with a detection limit of 9.5 nM. L can coordinate to Cu2+ and Mg2+ in a 1:1 molar ratio, respectively, evidenced by Job's plot analysis. Their binding modes were investigated by NMR, IR and XPS spectroscopies. Moreover, the satisfied results were obtained when L was used to detect Cu2+ and Mg2+ in real water samples.

Interfacial Passivation Enormously Enhances Electroluminescence of Triphenylphosphine Cu4 I4 Cube.

Defect is one of the key factors limiting optoelectronic performances of organic-inorganic hybrid systems. Although high-efficiency bidentate ligands based electroluminescent (EL) clusters reported, until present, only few EL clusters based on monodentate ligands are realized since their structural instability induces more surface/interface defects. Herein, this bottleneck is first overcome in virtue of interfacial passivation by electron transporting layers (ETL). Through using TmPyPB with meta-linked pyridines as ETL, photoluminescent (PL) and EL quantum efficiencies of the simplest monophosphine Cu4 I4 cube [TPP]4 Cu4 I4 are greatly improved by ≈2 and 23 folds, respectively, as well as ≈200 folds increased luminance, corresponding to a huge leap from nearly unlighted (<20 nits) to highly bright (>3000 nits). The passivation effect of TmPyPB on surface defects of cluster layer is embodied as preventing interfacial charge trapping and suppressing exciton nonradiation.

Selective detection of trace carbon monoxide at room temperature based on CuO nanosheets exposed to (111) crystal facets.

In recent years, carbon monoxide (CO) intoxication incidents occur frequently, and the sensitive detection of CO is particularly significant. At present, most reported carbon monoxide (CO) sensors meet the disadvantage of high working temperature. It is always a challenge to realize the sensitive detection of carbon monoxide at room temperature. In this study, CuO nanosheets exposed more (111) active crystal facets and oxygen vacancy defects were synthesized by a simple and environmentally friendly one-step hydrothermal method. The sensor has good comprehensive gas sensing performance, compared with other sensors that can detect CO at room temperature. The response value to 100 ppm CO at room temperature is as high as 39.6. In addition, it also has excellent selectivity, low detection limit (100 ppb), good reproducibility, moisture resistance and long-term stability (60 days). This excellent gas sensing performance is attributed to the special structural characteristics of 2D materials and the synergistic effect of more active crystal facets exposed on the crystal surface and oxygen vacancy defects. Therefore, it is expected to become a promising sensitive material for rapid and accurate detection of trace CO gas under low energy consumption, reduce the risk of poisoning, and then effectively protect human life safety.

Complexation and degradation of tetracycline by activation of molecular oxygen with biochar-supported nano-zero-valent copper composite.

Nano-zero-valent copper (nZVC) is a superior molecular oxygen (O2) activator for the abatement of organic pollutants due to its high electron utilization rate. However, the activation efficiency of O2 is compromised by the agglomeration tendency of nZVC particles and the concomitant reduction of the available active sites. To address this problem, the biochar (BC) with porous structure and abundant surface functional groups is utilized to disperse and stabilize nZVC for O2 activation (simplified as the nZVC/BC/O2 system) for efficient removal of tetracycline (TC). The nZVC/BC composite possesses a high specific area with well-distributed nZVC particles on the BC surface, which guarantees the superior dispersion and high reactivity in the activation of O2. The efficacy of the nZVC/BC/O2 system for TC abatement is evaluated and the underlying mechanism is elucidated. The results show that nZVC/BC/O2 system can achieve excellent removal of TC with the efficiencies of more than 85% in the pH range of 4.0-9.0, which originated from the combined action of complexation and degradation. The degradation is dominated by reactive oxygen species (ROS) including •OH, •O2- and 1O2 generated by Cu0/Cu+ activated O2 while the generation of Cu2+ via oxygen oxidation on the surface of nZVC/BC can remove TC by complexation adsorption. This study highlights the complexation and degradation in the removal of TC and can be expected to exhibit application prospects in the water and wastewater treatment.

Construction of Ultrathin S-Scheme Heterojunctions of Single Ni Atom Immobilized Ti-MOF and BiVO4 for CO2 Photoconversion of nearly 100% to CO by Pure Water.

To rationally design single-atom metal-organic framework (MOF)-involving photocatalysts remains an ongoing challenge for efficient CO2 conversion. Here, cuppy microstructures, consisting of a Ti(IV)-oxo node and three linked carboxylic moieties, in the single-coordination-layer Ti2 (H2 dobdc)3 MOF (NTU-9) are exploited to immobilize abundant single Ni(II) sites (Ni@MOF). The coupling of Ni@MOF with BiVO4 (BVO) nanosheets by H-bonding-induced assembly process obtains wide-spectrum 2D heterojunctions. The optimal heterojunction exhibits competitive performance and enables around 66-fold CO2 conversion of that for BVO nanoparticles by pure water, with nearly 100% CO selectivity. The exceptional photoactivity is attributed to favorable S-scheme charge transfer from BVO to MOF then to single Ni(II) sites. Noteworthily, single Ni(II) sites anchored by the Ti(IV)-oxo node and vicinal carboxylic moieties serving as a unique local microenvironment (LME) are found to synergistically catalyze CO2 conversion. Specifically, the hydroxyl groups of carboxylic moieties can form H-bonds with CO2 to promote its adsorption on single Ni(II) sites, and also can provide accessible protons to facilitate H-assisted CO2 reduction. Moreover, the CO desorption and subsequent CO2 adsorption on single Ni(II) sites with LME is proved to be thermodynamically favored, and hence dominates the high CO selectivity. This work highlights the significance of modulating the LME of single atoms to rationally design photocatalysts for realizing carbon neutralization.

Porous Cr2O3 Architecture Assembled by Nano-Sized Cylinders/Ellipsoids for Enhanced Sensing to Trace H2S Gas.

How to achieve high sensing of Cr2O3-based sensors for harmful inorganic gases is still a challenge. To this end, Cr2O3 nanomaterials assembled from different building blocks were simply prepared by chromium salt immersion and air calcination with waste scallion roots as the biomass template. The hierarchical architecture calcined at 600 °C is constructed from nanocylinders and nanoellipsoids (named as Cr2O3-600), and also possesses multistage pore distribution for target gas accessibility. Interestingly, the synergism of two shapes of nanocrystals enables the Cr2O3-based sensor to realize highly sensitive detection of trace H2S gas. At 170 °C, Cr2O3-600 exhibits a high response of 42.8 to 100 ppm H2S gas, which is 3.45 times larger than that of Cr2O3-500 assembled from nanocylinders. Meanwhile, this sensor has a low detection limit of 1.0 ppb (S = 1.4), good selectivity, stability, and moisture resistance. These results show that the combination of nanosized cylinders/ellipsoids together with exposed (104) facet can effectively improve the sensing performance of the p-type Cr2O3 material. In addition, the Cr2O3-600 sensor shows satisfactory results for actual monitoring of the corruption process of fresh chicken.

Controllable construction of ZnFe2O4-based micro-nano heterostructure for the rapid detection and degradation of VOCs.

Micro-nano heterogeneous oxides have received extensive attention due to their distinctive physicochemical properties. However, it is a challenge to prepare the hierarchical multicomponent metal oxide nanomaterials with abundant heterogeneous interfaces in a controllable way. In this work, the effective construction of the heterogeneous structure of the material is achieved by regulating the ratio of metal salts under thermal solvent condition. Three-dimensional spheres (ZnFe2O4) constructed by zero-dimensional ultra-small nanoparticles, in particular three-dimensional hollow sea urchin spheres (ZnO/ZnFe2O4) constructed by one-dimensional nanorods and three-dimensional hydrangeas (α-Fe2O3/ZnFe2O4) assembled by two-dimensional nanosheets were obtained. The two composite materials contain a large number of heterojunctions, which enhances the sensitivity of material to volatile organic compounds gas. Among them, the α-Fe2O3/ZnFe2O4 composite shows the best sensing performance for VOCs. For example, its response to 100 ppm acetone reaches 142 at 170 °C with the response time shortened to 3 s and the detection limit falling to 10 ppb. Meanwhile, the composite material presents a degradation rate of more than 90% for VOCs at a flow rate of 20 mL/min at 170 °C. In addition, the sensing and sensitivity mechanism of the composite material are studied in detail by combining GC-MS, XPS with UV diffuse reflectance tests.

In-situ deposition of POMA/ZnO nanorods array film by vapor phase polymerization for detection of trace ammonia in human exhaled breath at room temperature.

The o-methoxyaniline (OMA) monomer was polymerized in-situ by vapor phase polymerization to form uniform and dense poly-o-methoxyaniline (POMA) film on the surface of ZnO nanorods array film which was pre-prepared by hydrothermal method. The as-prepared POMA/ZnO composite shows the best response at 40 min of vapor phase polymerization time. The response to 100 ppm ammonia at 25 °C is 8.88. The recovery time of 136 s has a certain advantage in the reported room temperature ammonia sensors. The lowest detectable concentration is as low as 0.01 ppm. The fast recovery time and low detection limit make the sensor have broad application prospects. In order to explore the response mechanism of POMA/ZnO composite to ammonia gas, the work function of POMA and ZnO and corresponding band gap energies were tested respectively. And the effect of the formation of p-n heterostructure on gas response was further explored. The actual application test results reflect that the sensor can effectively identify NH3 in the mixed gas during the production, storage and transportation of NH3. This can provide real-time early warning of NH3 leakage. Especially, the sensor can detect trace amount of NH3 in the human body's exhaled breath which is expected to realize the preliminary screening of patients with kidney disease through the detection of exhaled breath in the medical field.

Non-enzymatic nitrite amperometric sensor fabricated with near-spherical ZnO nanomaterial.

A unique near-spherical ZnO nanostructure was synthesized by using mixed solvents composed of polyethylene glycol-400 (PEG-400) and water at the volume ratio of 12:1 via the solvo-thermal method, and it possessed an ideal morphology with higher uniformity, better dispersion and small particle size. Such ZnO was employed to modify glass carbon electrode (GCE) for the construction of electrochemical sensor, i.e. near-spherical ZnO/GCE, whose nitrite sensing performance was evaluated by Chronoamperometry (CA) and Linear Sweep Voltammetry (LSV). In order to emphasis the superior sensing property and extensive suitability for different electrochemical detection techniques, the excellent but not the same nitrite detection performance obtained from CA and LSV was individually given in detail. This sensor based on CA showed broad linearity range of 0.6 µM-0.22 mM and 0.46 mM-5.5 mM, improved sensitivity of 0.785 µA µM-1 cm-2 accompanied with low LOD of 0.39 µM. With regard to LSV, wide linearity response of 1.9 µM-0.8 mM and 1.08 mM-5.9 mM, high sensitivity of 0.646 µA µM-1 cm-2 with LOD of 0.89 µM were obtained. Meanwhile, this sensor displayed outstanding repeatability with RSD of 2.96% (n = 4), high reproducibility with low RSD (1.72%-2.35%, n = 4), strong selectivity towards nitrite with the concentration set at one-tenth of the interfering substances, ideal stability with the peak current intensity above 90% of its initial value after storage for one month and acceptable recovery of 1.72-2.35% to actual samples including ham sausage, pickle and tap water. The near-spherical ZnO nanomaterial may be a preferred candidate for the fabrication of nitrite electrochemical sensor, which may exhibit a fascinating application in terms of food analysis and environmental monitoring.

Activation of peracetic acid with zero-valent iron for tetracycline abatement: The role of Fe(II) complexation with tetracycline.

Peracetic acid (PAA) is an excellent oxidant that can produce multiple carbon-centered radicals (R•C). A novel advanced oxidation process (AOP) that combines PAA and nanoscale zero-valent iron (i.e. nZVI/PAA) is constructed to evaluate its performance toward tetracycline (TC) abatement. The nZVI/PAA process shows excellent abatement efficacy for TC in the pH range of 3.5-7.5. The presence of humic acid, HPO42- and HCO3- exerts inhibitory effects on TC abatement, while the presence of Cl- displays negligible influence in the nZVI/PAA process. Nanoscale zero-valent iron (nZVI) exhibits excellent reusability with no apparent variation in crystallinity. CH3C(O)OO• is the predominant active radical that contributes to TC abatement, in which leakage of Fe(II) from the nZVI surface is crucial for a radical generation. Due to the strong complexation tendency of TC towards Fe(II), the Fe(II)-TC complexes are formed, which significantly accelerates the PAA decomposition and TC abatement compared to free Fe(II). In addition, the degradation intermediates of TC are identified, and a possible degradation pathway is proposed. These results will be useful for the application of PAA-based AOPs in the treatment of water containing organic micropollutants.

Rapid detection of H2S gas driven by the catalysis of flower-like α-Bi2Mo3O12 and its visual performance: A combined experimental and theoretical study.

Metal oxide semiconductor (MOSs) are attractive materials for the development of H2S gas sensors. However, detecting H2S with short response and recovery times while also lowering the limit of detection to sub-ppb levels remains a significant challenge. We therefore developed flower-like α-Bi2Mo3O12 microspheres for H2S gas detection that provide fast response and recovery times (3 and 22 s, respectively, for 100 ppm H2S), while also reducing the limit of detection to 1 ppb. The sensor performs well in terms of sensitivity, reproducibility, long-term stability, including humidity stability. X-ray photoelectron spectroscopy (XPS) and density functional theory (DFT) calculations revealed that H2S dissociates readily on the reduced α-Bi2Mo3O12 surface and that Mo plays a catalytic role, accelerating the rate of H2S decomposition and enabling a fast response. Moreover, test strips containing α-Bi2Mo3O12 were also prepared, which enabled the naked eye detection of ppm-level H2S gas at room temperature; a light-yellow to orange to brown color change occurs when exposed to H2S, due to its conversion into stable sulfides. This work expands the application of α-Bi2Mo3O12 to H2S gas sensing, and provides a strategy for the use of MOSs as sensor materials for the detection of other gases.

Bimetallic MOFs-derived coral-like Ag-Mo2C/C interwoven nanorods for amperometric detection of hydrogen peroxide.

Coral-like Ag-Mo2C/C-I and blocky Ag-Mo2C/C-II composites were obtained from one-step in situ calcination of [Ag(HL)3(Mo8O26)]n·nH2O [L: N-(pyridin-3-ylmethyl) pyridine-2-amine] under N2/H2 and N2 atmospheres, respectively. The coral-like morphology of Ag-Mo2C/C-I is composed of interwoven nanorods embedded with small particles, and the nano-aggregate of Ag-Mo2C/C-II is formed by cross-linkage of irregular nanoparticles. The above composites are decorated on glassy carbon electrode (GCE) drop by drop to generate two enzyme-free electrochemical sensors (Ag-Mo2C/C/GCE) for amperometric detection of H2O2. In particular, the coral-like Ag-Mo2C/C-I/GCE sensor possesses rapid response (1.2 s), high sensitivity (466.2 µA·mM-1·cm-2), and low detection limit (25 nM) towards trace H2O2 and has wide linear range (0.08 µM~4.67 mM) and good stability. All these sensing performances are superior to Ag-Mo2C/C-II/GCE, indicating that the calcining atmosphere has an important influence on microstructure and electrochemical properties. The excellent electrochemical H2O2 sensing performance of Ag-Mo2C/C-I/GCE sensor is mainly attributed to the synergism of unique microstructure, platinum-like electron structure of Mo2C, strong interaction between Mo and Ag, as well as the increased active sites and conductivity caused by co-doped Ag and carbon. Furthermore, this sensor has been successfully applied to the detection of H2O2 in human serum sample, contact lens solution, and commercial disinfector, demonstrating the potential in related fields of environment and biology. Graphical abstract.

Fast detection of NO2 by porous SnO2 nanotoast sensor at low temperature.

In order to challenge high working temperature, low response and low selectivity of present NO2 sensor, porous SnO2 nanotoasts with a large surface area (79.94 m2/g) were synthesized. Thick film sensors fabricated by the SnO2 nanotoasts exhibited a high response to NO2 gas operating at room temperature. Excellent performance for NO2 sensing gas at 50 °C, included the high response of 105.2 (10 ppm), low detection limitation of 0.1 ppm, fast response within 10 s, and wide range of 0.1-10 ppm (R2 = 0.9931). These sensors also demonstrated perfect selectivity, moisture resistance and 90 days of long-term stability. SnO2 nanotoasts sensor has excellent detection ability in actual detection. The superior response of porous SnO2 nanotoasts towards NO2 was attributed to the special porous structure with large specific surface area and oxygen vacancies in sensing material, which helped adsorption of the target gas molecules onto the sensing surfaces and transfer of the charge.

Ionic liquid([C12mim][PF6])-assisted synthesis of TiO2 /Ti2O (PO4)2 nanosheets and the chemoresistive gas sensing of trimethylamine.

The architecture of PO43- modified 2D TiO2 nanosheets was constructed by ionic liquids (ILs)-assisted hydrothermal method. The nanosheet structure can be regulated by the addition of different amount of ionic liquid. Using the composite nanosheets  a chemoresistive gas sensor was prepared for trimethylamine (TMA) detection. Most reported TMA sensors need to be operated at a relatively high operating temperature, but in this paper, the as-synthesized PO43--modified 2D TiO2/Ti2O(PO4)2 nanosheet sensor has high response (S = 87.46), short response time (14.6 s), and good reproducibility to 100 ppm TMA gas, when the temperature is 170 °C. In contrast to the single-phase TiO2 sensor, the gas-sensing property of the composite one is obviously enhanced. Moreover, its response shows excellent linear relationship with TMA concentration from 0.2 to 500 ppm, and a detection limit of 0.2 ppm. The TMA detection mechanism was investigated by analyzing the changes of the surface adsorption oxygen content by XPS and gaseous products using gas chromatography after the sensor was in contact with TMA.