- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
α-Fe <sub/>2</sub> O <sub/>3</sub> Polyhedral Nanoparticles Enclosed by Different Crystal Facets: Tunable Synthesis, Formation Mechanism Analysis, and Facets-dependent <i>n</i> -Butanol Sensing Properties
摘要： Three kinds of polyhedral α-Fe2O3 nanoparticles enclosed by different facets including oblique parallel hexahedrons (op-hexahedral NPs), cracked oblique parallel hexahedrons (cop-hexahedral NPs), and octadecahedral nanoparticles (octadecahedral NPs), were successfully prepared by simply changing only one reaction parameter in the hydrothermal process. The structural and morphological of the products were systematically studied using various characterizations including X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM), revealing that the three kinds of α-Fe2O3 nanoparticles were enclosed by {104}, {110}/{104}, and {102}/{012}/{104} crystal planes, respectively. The exposed facets and shape of the nanocrystals were found to be affected by the adding amount of ethylene glycol in the solvent. The gas-sensing properties and mechanism of the α-Fe2O3 samples were studied and analyzed, which indicated that the sensitivity of the three samples followed the order of octadecahedral NPs (cid:2) cop-hexahedral NPs (cid:2) op-hexahedral NPs due to the combined effects of specific surface area and oxygen defects in the nanocrystals.
关键词： Polyhedron,n-Butanol,Hydrothermal synthesis,α-Fe2O3 nanoparticles,Gas-sensing
更新于2025-11-14 17:03:37
-
ZnO-enhanced In2O3-based sensors for n-butanol gas
摘要： A series of high-response and fast-response/recovery n-butanol gas sensors was fabricated by adding ZnO to In2O3 in varying molar ratios to form ZnO-In2O3 nanocomposites via a facile co-precipitation hydrothermal method. Morphological characterizations revealed that the shape of pure In2O3 was changed from irregular cubes into irregular nanoparticles, 30-50 nm in size, with the addition of ZnO. Compared with the pure In2O3 gas sensor, the ZnO-In2O3 gas sensor exhibits superior n-butanol sensing performance. With the introduction of ZnO, the response of the sensor to n-butanol was improved from 17 to 99.5 at 180 °C for a [Zn]:[In] molar ratio of 1:1. In addition, the ZnO-In2O3 gas sensors show a reduced optimal working temperature, excellent selectivity to n-butanol, and good repeatability. The response of the ZnO-enhanced In2O3-based sensors showed a strong linear relationship with the n-butanol gas concentration, allowing for the quantitative detection of n-butanol gas.
关键词： ZnO-In2O3,n-Butanol,Gas-sensing property,Selectivity
更新于2025-09-23 15:23:52
-
Nanocrystalline ZnO Obtained by the Thermal Decomposition of [Zn(H2O)(O2C5H7)2] in 1-Butanol: Synthesis and Testing as a Sensing Material
摘要： The influence of conditions of heat treatment of a solution [Zn(H2O)(O2C5H7)2] in 1-butanol (temperature 125–185°C, treatment times 2, 4, and 6 h) on dispersion and microstructure of the formed nanocrystalline and poorly aggregated zinc oxide, promising component for optoelectronics, including as receptor materials of chemical gas sensors, was investigated. IR spectroscopy showed that the precursor decomposition occurs through the cleavage of the Cβ–Cγ bond of the ligand to form acetone and butyl acetate. It was determined that at the minimum treatment temperature and time (125°C, 2 h) ZnO nanoparticles are nearly spherical, and under hard conditions, rodlike particles are formed. At 125°C (treatment times 4 and 6 h), rodlike particles are organized into dense agglomerates resembling bundles in shape, and at the higher temperatures there is no aggregation of ZnO nanoparticles. The high CO selectivity and sensitivity (4–100 ppm) was revealed for oxide coatings obtained by screen printing using ZnO nanopowders synthesized at 125°C (treatment times 2 and 4 h).
关键词： ZnO,acetylacetonate,zinc oxide,gas sensor,nanoparticles,1-butanol
更新于2025-09-23 15:21:21
-
Cataluminescence sensor for highly sensitive and selective detection of iso-butanol
摘要： In this paper, a gaseous sensor was described for detection of iso-butanol on the basis of its strong cataluminescence (CTL) emission on nano-MgO surface. The sensor showed high sensitivity and specificity to iso-butanol with response time less than 1 s and recovery time less than 18 s. A good linearly relationship between CTL intensity and the concentration of iso-butanol was observed in the range of 7.6 to 3350 mg/m3 (r = 0.9992), the limit of detection was 2.5 mg/m3. The proposed CTL sensor exhibits good specificity to iso-butanol against other compounds including common alcohols. The possible reaction paths of iso-butanol on the MgO surface were investigated in detail. Results shows that the hydrogen atom abstraction of iso-butanol to form β-Riso following consumption via Waddington mechanism possible is a major reaction channel for CTL emission. The sensor was applied to analyze iso-butanol in spiked samples, satisfactory recoveries were obtained in the range of 96.6 to 112.8% and the RSDs were 5.0 to 10.1%, indicating that the proposed sensor is a promising candidate for rapid analysis of iso-butanol.
关键词： Cataluminescence,Nanosized MgO,Chemiluminescence,Iso-butanol,Sensor
更新于2025-09-23 15:21:21
-
Coupled photothermal and joule-heating process for stable and efficient interfacial evaporation
摘要： A trade-off inevitably exists between soot and NOX emissions in a traditional engine. The addition of an oxygen-containing biofuel can decrease the soot emission but increase the NOX emission. Multi-injection strategy can be used to decrease the NOX emission. Therefore, both simulations and experimental tests were conducted to evaluate the influences of pre-injection on the combustion and emission characteristics of pure diesel (D100) and diesel/n-butanol (30% n-butanol and 70% diesel by volume, B30). The results showed that as the pre-injection interval decreased, the in-cylinder pressure peak increased, the pre-injection heat release ratio increased, and the brake-specific fuel consumption (BSFC) decreased. Only at a small pre-injection interval, the BSFC under pre-injection condition was lower than that obtained using the single injection strategy. When the same pre-injection strategy was used, B30 had a higher BSFC and lower brake thermal efficiency than D100. The soot emission decreased with the increase in pre-injection interval but increased with the increase in pre-injection ratio. More soot was emitted using the pre-injection strategy than that using single injection strategy. B30 had a lower soot emission than D100 due to a longer ignition delay. As the pre-injection interval increased, the decreasing amplitude of NO production became smaller than the increasing amplitude of NO2 production, thus increasing the net NOX emission. As the pre-injection ratio increased, more CO was produced through the reaction paths CH2O → HCO → CO, whereas the transformation of CO to CO2 almost remained unchanged, thus increasing the net CO emission. The increase in pre-injection ratio inhibited the oxidation of CO to CO2 and thus increased the CO emission. The amount of unburned hydrocarbons increased with the increase in both pre-injection ratio and interval.
关键词： Chemical kinetics,CFD,Pre-injection,Diesel/n-butanol blends,Low-temperature combustion
更新于2025-09-16 10:30:52
-
Induced Circular Dichroism of Jet-Cooled Phenol Complexes with <i>R</i> -(–)-2-Butanol
摘要： The induced circular dichroism (ICD) of phenol complexed with R-(–)-2-butanol (PhOH-(–)BOH) in a supersonic jet is investigated using resonant two-photon ionization CD (R2PICD) spectroscopy. The R2PICD spectrum of PhOH-(–)BOH exhibits nonzero ICD bands near the absorption region of bare PhOH, where (–)BOH is transparent. Two different conformers containing a single hydrogen bond between PhOH and (–)BOH are identified using ultraviolet(UV)-UV hole-burning and infrared (IR) ion-dip spectroscopy combined with quantum theoretical calculations. The ICD values of the two conformers are similar to each other. To understand these similar ICD effects of the conformers, the geometrical asymmetry of the PhOH moiety bound to (–)BOH and the coupling strength of the electric transition dipole moments between PhOH and (–)BOH are estimated. Comparing the ICD values of PhOH-(–)BOH with those of PhOH-(–)-L-methyl lactate in the previous report (Hong, A.; Moon, C. J.; Jang, H.; Min, A.; Choi, M. Y.; Heo, J.; Kim, N. J. J. Phys. Chem. Lett. 2018, 9, 476-480), we investigate the physical properties that may govern the differences of the ICD values between the two complexes.
关键词： R-(–)-2-Butanol,Phenol Complexes,Supersonic Jet,Resonant Two-Photon Ionization CD Spectroscopy,Induced Circular Dichroism
更新于2025-09-12 10:27:22