- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Hierarchical Au-Loaded WO3 Hollow Microspheres with High Sensitive and Selective Properties to Toluene and Xylene
摘要： Functionalization of metal-oxide semiconductors by noble metal nanoparticles is one of the most efficient methods for enhancing the gas-sensing property of semiconducting sensors. Herein, we synthesized a series of Au-loaded hierarchical WO3 hollow microspheres (Au-WO3) via a facile modified solvothermal method combining with wet impregnation method. The structure, elemental composition and morphology of the synthesized materials were characterized by X-ray powder diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM) and transmission electron microscopy (TEM). The results show that the materials are uniform and independent WO3 hollow microspheres, and Au nanoparticles are well distributed on the surface of WO3. The gas sensing properties of Au-WO3 materials were investigated and the results suggest that Au loading could greatly improve gas sensing performance of WO3 to aromatic compounds, especially toluene and xylene. Among the samples with different Au loading content, the one with 1.5 wt% Au (G3) exhibits the highest responses toward toluene and xylene at 340 °C. Moreover, the G3 sensor presents good responses, short response/recovery time, excellent selectivity, good reproducibility and long-term stability to toluene and xylene. Excellent gas sensing properties of Au-WO3 material make it a good candidate for detecting toluene and xylene.
关键词： toluene,Au-WO3,selectivity,xylene
更新于2025-11-14 17:03:37
-
Photocatalytic oxidation of gaseous benzene, toluene and xylene under UV and visible irradiation over Mn-doped TiO2 nanoparticles
摘要： The photocatalytic oxidation of gaseous benzene, toluene and xylene (BTX) over un-doped, 0.1 and 1 wt% Mn-TiO2 nanoparticles under ultraviolet and visible irradiation was studied in atmosphere of synthetic air or inert gas. The photocatalytic decomposition efficiency and the oxidation products were determined using a Static Photochemical Reactor coupled with FTIR spectroscopy. BTX underwent efficient decomposition over Mn-TiO2 photocatalysts under UV irradiation, more with oxygen presence and less without oxygen. More important toluene and xylene went substantial decomposition over 0.1 mol% Mn-TiO2 under visible irradiation with oxygen presence. The main final oxidation products in the UV photocatalysis of BTX were CO2, CO and H2O, with CO2 and CO yields 4 and 2 respectively. The conversion percentage of benzene, toluene, and xylene to CO2 were 63.6%, 56.4%, 51.8%, and to CO 29%, 26.5%, 23.2%, respectively. In the visible photocatalysis of toluene and xylene the yields of CO were insignificant. Formation of carbon containing deposits on TiO2 surfaces was observed after extensive UV photocatalysis of toluene and xylene, and such by-products surface coverage may reduce the photocatalytic activity of TiO2 samples. Some aspects of the photocatalytic mechanism were examined.
关键词： Mn-doped TiO2,Visible - light photocatalysis,Photodegradation of Benzene,Indoors air pollution,Xylene,Toluene
更新于2025-09-23 15:23:52
-
Nickel Doping on Cobalt Oxide Thin Film Using by Sputtering Process-a Route for Surface Modification for p-type Metal Oxide Gas Sensors
摘要： This study proposes a route for surface modification for p-type cobalt oxide-based gas sensors. We deposit a thin layer of Ni on the Co oxide film by sputtering process and annealed at 350 °C for 15 min in air, which changes a typical sputtered film surface into one interlaced with a high density of hemispherical nanoparticles. Our in-depth materials characterization using transmission electron microscopy discloses that the microstructure evolution is the result of an extensive inter-diffusion of Co and Ni, and that the nanoparticles are nickel oxide dissolving some Co. Sensor performance measurement unfolds that the surface modification results in a significant sensitivity enhancement, nearly 200% increase for toluene (at 250 °C) and CO (at 200 °C) gases in comparison with the undoped samples.
关键词： Toluene,Co oxide thin film,Ni-doped,Gas sensor,RF sputtering,CO
更新于2025-09-23 15:22:29
-
Facile synthesis of NaOH-promoted Pt/TiO2 catalysts for toluene oxidation under visible light irradiation
摘要： NaOH-promoted Pt/TiO2 catalysts are successfully prepared by a facile impregnation method assisted by NaOH and tested for the toluene oxidation reaction under visible light irradiation. Keeping molar ratio of Pt:Na =1:8, the 0.1Pt-Na/TiO2 catalyst (0.1 mol% Pt) shows excellent catalytic performance with more than 60% of toluene conversion at 45 oC and achieving total toluene removal at 280 oC, which is significantly better than 0.1Pt/TiO2 catalyst. The structures and properties of catalysts are characterized by XRD, SEM, N2 adsorption, XPS and UV-vis spectra. The positively charged Pt species stabilized by NaOH are the most active sites for photo-thermal catalyzing toluene oxidation. The influence of Pt loading and the effect of supports (active TiO2 and inert Al2O3) are also discussed.
关键词： photo-thermal catalysis,toluene oxidation,TiO2,NaOH,Pt
更新于2025-09-23 15:21:21
-
Rice husk derived nano-NiFe2O4@CAGC-catalyzed direct oxidation of toluene to benzyl benzoate under visible LED light
摘要： Here, we report an efficient and highly selective oxidation of primary carbon-hydrogen bond in toluene catalyzed by biomass, rice husk derived chemically activated graphitic carbon supported NiFe2O4 (nano-NiFe2O4@CAGC) nanomaterial under LED light. The hybrid nanocatalyst showed excellent activity and selectivity towards direct oxidation of toluene to benzyl benzoate. The nano-NiFe2O4@CAGC has also demonstrated superior catalytic activity compared to its individual components. The catalyst was very robust and stable under the reaction conditions, and was separated from the reaction mixture by an external magnet and reused for subsequent reactions.
关键词： reusable catalyst,nano-NiFe2O4@CAGC,oxidation of toluene to benzyl benzoate,hybrid nanocatalyst,LED light
更新于2025-09-23 15:21:01
-
Self-assembled flower-like (BiO)2CO3a??CdSa??CuS stable heterojunction degrades toluene under visible light response
摘要： The toluene as a representative VOCs is not only difficult to degrade, but also very harmful. In this manuscript, we use photocatalytic materials to degrade toluene. At first, the sheet-like structure decorated (BiO)2CO3 flowers were fabricated. The tight decoration of sheet-like structure over (BiO)2CO3 flowers provided greater specific surface area to contact with the toluene. Finally, the (BiO)2CO3 and CdS–CuS were fabricated to form a ternary heterojunction by one-step hydrothermal method. The activity enhancement should be ascribed to that the ternary heterojunction could produce more active material ?OH for toluene degradation. The 3p-orbital in the sulfur atom in CuS can be used as an electron acceptor to effectively improve the stability of sulfur vacancies on the surface of CdS. In addition, the presence of CuS could solve the problem of deactivation caused by photo-etching of CdS under illumination conditions. The valence change of the S element in CuS-CdS-BOC is only 1.1%, but up to 7.5% in CdS-BOC before and after the reaction. The highest degradation effect was exhibited, the degradation of toluene at 3000 ppm could reach 67%. In addition, The band gap of the composite material was reduced from 3.2eV to 2.25eV. A new alternative catalytic material was provided for the degradation of toluene. A reliable strategy was provide for enhancing the stability of S in CdS by this work.
关键词： Toluene,Stability,Photocatalysis,Free radicals
更新于2025-09-23 15:21:01
-
Luminescence interference to two-colour toluene laser-induced fluorescence thermometry in a particle-laden flow
摘要： We present the use of two-colour toluene planar laser-induced fluorescence (LIF) to obtain spatially resolved measurements of the gas temperature ( T g ) in a particle-laden turbulent flow under sufficiently dense particle loading that the interference from laser interactions with the particles is significant. The effect of the ratio of volumetric flow rates of the particle phase to the gas phase ( ?? ) on the accuracy and precision of two-colour toluene LIF thermometry was systematically investigated for three particle materials, alumina, zinc activated zinc oxide (ZnO:Zn) and polymethyl methacrylate (PMMA), each of which has differing interactions with the excitation laser. The PMMA particles were spherical and mono-disperse with diameters of 6 to 40 μm , while the alumina and ZnO:Zn particles had diameters in the range 1–40? μm and 2–200?μm, respectively. The results show that the accuracy of the gas temperature measurement is insensitive to particle size for the PMMA particles, but dependent on the instantaneous particle loading. Importantly, reliable measurements can be performed in the dense two-way coupling regime, with the measurement being accurate to within 5?°C for ???<?2.5 × 10?4 for the PMMA particles and for ?? < 7.6 × 10?4 for the alumina and ZnO:Zn particles.
关键词： volumetric flow rates,gas temperature measurement,particle-laden flow,two-colour toluene LIF,particle materials
更新于2025-09-23 15:19:57
-
Phase-equilibrium measurement of a carbon dioxide/toluene/polystyrene ternary system using laser turbidimetry
摘要： The phase behavior of a carbon dioxide (CO2)/toluene (Tol)/polystyrene (PS) ternary system was measured. The measurements were performed using a synthetic method combined with a reflected light intensity measurement. The bubble points were determined by visual observation, and the cloud points were determined from the change in the reflected light intensity. The phase boundaries were measured at temperatures ranging from 313.2 K to 373.2 K and CO2 weight fractions ranging from 0.10 to 0.41. The homogeneous phase area decreased when the molecular weight of PS and/or the ratio of PS to Tol increased. It was found that the phase behavior of ternary systems, especially the liquid-liquid phase separation behavior, was altered by a change in the mutual solubility between the three components.
关键词： Toluene,Synthetic method,Carbon dioxide,Vapor-liquid equilibrium,Vapor-liquid-liquid equilibrium,Polystyrene,Laser turbidimetry,Liquid-liquid equilibrium
更新于2025-09-16 10:30:52
-
Femtosecond Laser Synthesis of Luminescent Carbon Dots from Toluene
摘要： Products of reactions in toluene induced by nonlinear absorption of femtosecond laser pulses are studied. Laser synthesis of carbon dots with characteristic sizes of several nanometers and luminescence in the visible spectrum is demonstrated. A relation between synthesis conditions, morphology, and composition of carbon dots and their optical properties is established. The possibility of single-stage laser synthesis of polyethylene glycol passivated carbon dots having an enhanced quantum yield and improved spectral characteristics of luminescence is demonstrated. The results of the work open up new opportunities for obtaining promising carbon nanomaterials and optimizing their optical properties through the use of femtosecond laser pulses.
关键词： carbon dots,luminescence,toluene,femtosecond laser,polyethylene glycol
更新于2025-09-12 10:27:22
-
Enhanced Sensing Performance to Toluene and Xylene by Constructing NiGa2O4-NiO Heterostructures
摘要： The selective detection of methyl benzene (e.g. toluene and xylene) using oxide semiconductor-based gas/vapor sensors is highly desirable but limited by the low chemical reactivity of the benzene compounds. Exploiting p-type semiconductor oxides (e.g., NiO) which provide distinctive catalytic activities for methyl benzene detection is an essential approach. However, the intrinsic responses of p-type semiconductor oxides are often low. In this paper, high-performance toluene and xylene detection has been realized by a sensor based on novel p-p heterojunction NiGa2O4-NiO nanospheres. Construction of optimized p-p heterojunctions, which resulting from the rationally controlling of the NiGa2O4 content in NiGa2O4-NiO, leads to significantly promoted sensing properties for toluene and xylene detection. It is found that the sensor based on 50% NiGa2O4-NiO exhibits the best sensing performances. Its highest response (Rg/Ra = 12.7 to toluene; Rg/Ra = 16.3 to xylene) is almost 10 times higher than that of the pure NiO (Rg/Ra < 2) to 100 ppm toluene and xylene at 230 oC. More importantly, the sensor exhibits superior selectively for detection of the methyl benzene even against more reactive interfering gases/vapors, such as formaldehyde and ethanol. The p-p oxide heterojunction suggests a promising sensing material for toluene and xylene detection with high response, excellent selectivity, good stability and rapid response/recover time.
关键词： Composite semiconductor,NiO,NiGa2O4,Heterojunction,Xylene,Toluene
更新于2025-09-10 09:29:36