Browse
Submit Data
Databases
API
Help

Dataset Information

21 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Acetone Sensing Properties and Mechanism of Rh-Loaded WO₃ Nanosheets.

ABSTRACT: WO₃ nanosheets was prepared by an acidification method and the Rh catalyst was dispersed on the surface of the nanosheets with a wet impregnation method. The morphology of pristine WO₃ and Rh modified WO₃ nanosheets and their responses to acetone gas were studied. According to oxygen adsorption combined with TPR results, the sensing and sensitization mechanism of acetone were discussed. It was found that no visible changes in nanostructures or morphologies were observed in WO₃ nanosheets with Rh, however, the sensor resistance and sensor response were greatly promoted. The basic sensitization mechanism could be caused by the electronic interaction between oxidized Rh and WO₃ surface.

SUBMITTER: Qiu Z

PROVIDER: S-EPMC6141622 | biostudies-literature | 2018

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Acetone Sensing Properties and Mechanism of Rh-Loaded WO3 Nanosheets.

Qiu Zhilei Z Hua Zhongqiu Z Li Yan Y Wang Mengjun M Huang Dan D Tian Chen C Zhang Chensheng C Tian Xuemin X Li Erping E

Frontiers in chemistry 20180911

WO3 nanosheets was prepared by an acidification method and the Rh catalyst was dispersed on the surface of the nanosheets with a wet impregnation method. The morphology of pristine WO3 and Rh modified WO3 nanosheets and their responses to acetone gas were studied. According to oxygen adsorption combined with TPR results, the sensing and sensitization mechanism of acetone were discussed. It was found that no visible changes in nanostructures or morphologies were o ...[more]

PMID: 30255011

Similar Datasets

Mesoporous WO3 Nanofibers With Crystalline Framework for High-Performance Acetone Sensing.

Project description:Semiconducting metal oxides with abundant active sites are regarded as promising candidates for environmental monitoring and breath analysis because of their excellent gas sensing performance and stability. Herein, mesoporous WO3 nanofibers with a crystalline framework and uniform pore size is successfully synthesized in an aqueous phase using an electrospinning method, with ammonium metatungstate as the tungsten sources, and SiO2 nanoparticles and polyvinylpyrrolidone as the sacrificial templates. The obtained mesoporous WO3 nanofibers exhibit a controllable pore size of 26.3-42.2 nm, specific surface area of 24.1-34.4 m2g-1, and a pore volume of 0.15-0.24 cm3g-1. This unique hierarchical structure, with uniform mesopores and interconnected channels, could facilitate the diffusion and transportation of gas molecules in the framework. Gas sensors, based on mesoporous WO3 nanofibers, exhibit an excellent performance in acetone sensing with a low limit of detection (<1 ppm), short response-recovery time (24 s/27 s), a linear relationship in a broad range, and good selectivity.

| S-EPMC6482242 | biostudies-literature

Effects of WO3 electrode microstructure on NO2-sensing properties for a potentiometric sensor.

Project description:Planar potentiometric NO2 sensors based on 8YSZ (8 mol% Y2O3-doped ZrO2) were prepared with WO3 sensing electrode material. The various electrode microstructures prepared by different sintering temperatures were characterized by field emission scanning electron microscopy (SEM), and the microstructure influences on the sensors' performances were investigated. The sensor sintered at 800°C, with the most reaction sites, moderate adsorption sites and appropriate electrode thickness, exhibits the highest NO2 voltage response. While the sensor sintered at 750°C exhibits the lowest NO2 sensitivity because of the strongest gas-phase catalytic consumption in the WO3 sensing electrode. Based on the results of SEM characterization and electrochemical impedance spectroscopy tests, the difference in NO2-sensing performance was attributed to different amounts of electrochemical reaction sites at three-phase boundary, adsorption sites and different degrees of gas-phase catalysis.

| S-EPMC6689626 | biostudies-literature

Two-Dimensional Bi2WO6 Nanosheets as a Robust Catalyst toward Photocyclization.

Project description:The present work describes the improved photocatalytic activity of cetyl trimethylammonium bromide (CTAB)-assisted Bi2WO6 (CBTH) toward the synthesis of bioactive benzazoles. X-ray diffraction analysis of CBTH suggests that crystal growth has occurred along the (200) plane, whereas field-emission scanning electron microscopy images confirm two-dimensional rose bud morphology and high-resolution transmission electron microscopy analysis suggests the formation of thin nanosheets possessing an orthorhombic structure. Temperature-programmed desorption of ammonia and Py-IR measurements indicate substantial acidity with the generation of Brønsted acid sites on the surface of CBTH. Raman spectra of CBTH also corroborate these observations with the formation of defects within [Bi2O2]2+ layers, resulting in decreased thickness and shapes of nanoplates. These beneficial properties are explored toward the photochemical synthesis of benzazoles using a 35 W tungsten lamp and a CBTH photocatalyst, resulting in better yields at lesser exposure time. It is observed that the catalytic activity is retained up to five consecutive cycles with marginal decrease in % yield. Such a feature can be ascribed to the photostability of the photocatalyst even after continuous exposure to light, implying that the surface active sites remained unaltered as evident from the X-ray photoelectron spectroscopy analysis of pre- and post-characterization of CBTH. Moreover, decrease in the surface hydroxyl groups after five catalytic cycles also accounts for the generation of enhanced Brønsted sites owing to the presence of Bi-O on the surface of CBTH. It exhibits better catalytic activity as compared to other photocatalysts employed for the synthesis of benzazoles. Thus, CBTH serves as a robust photocatalyst for the facile synthesis of these heterocycles in a sustainable manner.

| S-EPMC6045366 | biostudies-literature

Correction to "Two-Dimensional Bi2WO6 Nanosheets as a Robust Catalyst toward Photocyclization".

Project description:[This corrects the article DOI: 10.1021/acsomega.7b01086.].

| S-EPMC6645211 | biostudies-literature

PVP-Modified Multifunctional Bi2WO6 Nanosheets for Enhanced CT Imaging and Cancer Radiotherapy.

Project description:Malignant tumors are one of the main causes of human death. The clinical treatment of malignant tumors is usually surgery, chemotherapy, radiotherapy, and so forth. Radiotherapy, as a traditional and effective treatment method for cancer, is widely used in clinical practice, but the radiation resistance of tumor cells and the toxic side effects to normal cells are still the Achilles heel of radiotherapy. Multifunctional inorganic high-atom nanomaterials are expected to enhance the effect of tumor radiotherapy. Tungsten and bismuth, which contain elements with high atomic coefficients, have strong X-ray energy attenuation capability. We synthesized Bi2WO6 nanosheets (NSs) using a hydrothermal synthesis method and modified polyvinylpyrrolidone (PVP) on their surface to make them more stable. PVP-Bi2WO6 NSs have a variety of effects after absorbing X-rays (such as the photoelectric effect and Compton effect) and release a variety of particles such as photoelectrons, Compton electrons, auger electrons, and so forth, which can react with organic molecules or water in cells, generate a large number of free radicals, and promote cell apoptosis, thereby improving the effect of radiotherapy. We show through γ-H2AX and DCFH-DA probe analysis experiments that PVP-Bi2WO6 NSs can effectively increase cell DNA damage and reactive oxygen species formation under X-ray irradiation. Clone formation analysis showed that PVP-Bi2WO6 NSs can effectively suppress cell colony formation under X-ray irradiation. These versatile functions endow PVP-Bi2WO6 NSs with enhanced radiotherapy efficacy in animal models. In addition, PVP-Bi2WO6 NSs can also be used as contrast agents for X-ray computed tomography (CT) imaging with obvious effects. Therefore, PVP-Bi2WO6 NSs can be used as CT imaging contrast agents and tumor radiotherapy sensitizers and have potential medical applications.

| S-EPMC9178605 | biostudies-literature

Surface Oxygen Deficiency Enabled Spontaneous Antiprotein Fouling in WO3 Nanosheets for Biosensing in Biological Fluids.

Project description:Biofouling deteriorates the performance of sensors operated in biofluids. Protein adsorption is believed to be the first step of biofouling, which also reduces biocompatibility by further inducing cell adhesion, platelet activation, and even inflammation. Current studies of antifouling coatings are focused on polymers and hydrogels, which have succeeded in remaining resistant to protein adsorption, but their application on sensor electrodes is limited due to low conductivity and biocompatibility. Here, we report a spontaneous antibiofouling strategy for sensor electrodes by controlling oxygen vacancies in WO3 nanosheets. Irreversible adsorption of proteins was reduced by 76% in unprocessed human plasma when electrodes were coated with WO3 rich in surface oxygen vacancy. These electrodes maintained 91% of the initial current density after 1 month of incubation in human plasma.

| S-EPMC10794997 | biostudies-literature

Di-?-carbonyl-bis-[bis-(triphenyl-phos-phane)rhodium(0)](Rh-Rh) acetone disolvate.

Project description:The dirhodium complex, [Rh(2)(C(18)H(15)P)(4)(CO)(2)]·2(CH(3))(2)CO, has crystallographic twofold symmetry and the Rh-Rh distance is 2.6266?(8)?Å. The four atoms proximate to each Rh atom [Rh-P = 2.3222?(7) and 2.3283?(8)?Å, and Rh-C = 1.961?(3) and 2.045?(3)?Å] form a distorted tetra-hedron with large deviations from the putative tetra-hedral angles [r.m.s. deviation = 23?(1)°]. The six angles more closely approximate those of a trigonal bipyramid [r.m.s. deviation = 14?(1)°] with one missing equatorial ligand. The two bridging carbonyl ligands are much more linearly coordinated to one Rh [Rh-C O = 151.0?(2)°] than to the other [127.0?(2)°], and the two Rh(2)CO planes form a dihedral angle of 45.43?(5)°. The two acetone solvent mol-ecules are disordered, and their estimated scattering contribution was subtracted from the observed diffraction data using the SQUEEZE routine in PLATON [Spek (2009 ?). Acta Cryst.D65, 148-155].

| S-EPMC3515148 | biostudies-literature

Selective gas detection using Mn3O4/WO3 composites as a sensing layer.

Project description:Pure WO3 sensors and Mn3O4/WO3 composite sensors with different Mn concentrations (1 atom %, 3 atom % and 5 atom %) were successfully prepared through a facile hydrothermal method. As gas sensing materials, their sensing performance at different temperatures was systematically investigated for gas detection. The devices displayed different sensing responses toward different gases at specific temperatures. The gas sensing performance of Mn3O4/WO3 composites (especially at 3 atom % Mn) were far improved compared to sensors based on pure WO3, where the improvement is related to the heterojunction formed between the two metal oxides. The sensor based on the Mn3O4/WO3 composite with 3 atom % Mn showed a high selective response to hydrogen sulfide (H2S), ammonia (NH3) and carbon monoxide (CO) at working temperatures of 90 °C, 150 °C and 210 °C, respectively. The demonstrated superior selectivity opens the door for potential applications in gas recognition and detection.

| S-EPMC6664411 | biostudies-literature

Ultrasonically prepared photocatalyst of W/WO3 nanoplates with WS2 nanosheets as 2D material for improving photoelectrochemical water splitting.

Project description:A sonochemical treatment has been an emerged technique as an interesting method for fabricating different photocatalysts with unique photoelectrochemical (PEC) properties. This study investigated the PEC performance of WO3 with WS2 nanosheets as a 2D material before calcination (WO3/WS2-90) and after calcination (WO3/WS2-450) prepared with sonochemical treatment. The WS2 nanosheets were prepared from a liquid exfoliation phase with few-layer nanosheets, approximately 6.5 nm in thickness. The nanosheets were confirmed by UV-Vis spectroscopy and atomic force microscopy. Further, XPS, RAMAN, and SEM-EDAX analyses indicated that, following calcination of the WO3/WS2 electrode, the WS2 nanosheets initially transformed to 2D-WO3. After depositing the WS2 nanosheets on the WO3, the photocurrent density increased substantially. The WO3/WS2-450 films after calcination showed a photocurrent density of 5.6 mA.cm-2 at 1.23 V vs. Ag/AgCl, which was 3.1 and 7.2 times higher, respectively than those of the WO3/WS2-90 before calcination and pure WO3. Mott-Schottky and electrochemical impedance spectroscopy analyses confirmed the fabrication of the WO3/WS2 photoanode after calcination. The deposition of WS2 nanosheets onto pure WO3 increased the donor concentration (24-fold), reduced the space charge layer (4.6-fold), and decreased the flat band potential (1.6-fold), which could all help improve the photoelectrochemical efficiency. Moreover, the incorporation of WO3 with WS2 nanosheets as a 2D material (WO3/WS2-450) enhanced the incident photon current efficiency (IPCE) by 55%. In addition, the applied-bias photon-to-current conversion efficiency of the WO3/WS2-450 films was approximately 2.26% at 0.75 V (vs. Ag/AgCl), which is 5.6 and 9 times higher, respectively than those of WO3/WS2-90 and pure WO3.

| S-EPMC7786633 | biostudies-literature

Enhanced CO Sensing Performances of PdO/WO3 Determined by Heterojunction Structure under Illumination.

Project description:The CO sensing performances and mechanism of PdO/WO3-based sensors were investigated by experiments and density functional theory calculations. The CO sensing performance can be significantly enhanced by decorating WO3 with PdO, which is attributed to the catalyst (chemical sensitization) and P-N junction (electronic effect). On the one hand, PdO is an excellent catalyst used to promote the adsorption of oxygen species. On the other hand, the constructed P-N junction structure between PdO and WO3 can facilitate the migration of carriers and suppress the recombination of electrons and holes, which promote the adsorption of more oxygen species. Furthermore, the calculation results verify that decorating WO3 with PdO can significantly enhance the CO sensing response by providing more adsorption sites available for oxygen species and make more electrons to transfer from CO to PdO/WO3 configuration. Moreover, the band gap energies of the WO3 sensor can be reduced by PdO decoration, and the light absorption range in the visible light region can be expanded. More photogenerated electron-hole pairs can be produced based on the P-N junction structure, which can promote the progress of electrochemical reactions. Thus, the PdO/WO3 material can be a promising candidate to detect CO, and it can effectively utilize the UV-visible light to destruct the CO contaminant.

| S-EPMC7659150 | biostudies-literature