Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 33
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Nanoscale ; 2022 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-35037928

RESUMO

MOFs have been widely used as templates to design and construct catalysis materials, such as LDH, metal oxides, and carbon. Herein, we developed a Cu-mediated pyrolysis protocol for the synthesis of urchin-like CuOx/Fe2O3 hybrid nanostructures using Fe-MOFs as the precursor. The hierarchical hybrids were composed of an inner CuOx-dispersed Fe2O3 octahedral matrix covered with radially grown Fe2O3 nanorods. This novel hierarchical hybrid nanostructure was generated likely due to the difference in the inward contraction rates between the Cu and Fe species during pyrolysis. Given the structural and compositional benefits, the urchin-like CuOx/Fe2O3 hybrids exhibited outstanding catalytic activity for the chemical reduction of 4-nitrophenol (4-NP) and dyes. Besides, CuOx/Fe2O3 was found to be highly catalytic in the reduction of 4-NP even after 30 consecutive runs, manifesting outstanding durability for continuous operation.

2.
Sci Total Environ ; 813: 152637, 2021 Dec 25.
Artigo em Inglês | MEDLINE | ID: mdl-34963612

RESUMO

Chromite ore processing residue (COPR) has been a severe environmental contaminant which is worthy of attention. In this study, we developed an eco-friendly and practical technology for effectively stabilizing and recovering Cr(VI) in COPR via combining FeSO4 reducing agent and the hydrothermal treatment. A stable spinel phase product was formed during detoxification. In addition, the ferrochrome resources in the treated COPR can be obtained by magnetic separation. As we studied, the hydrothermal environment promoted the release of unstable Na2CrO4 from COPR into the solution, and the released CrO42- was reduced to Cr(III) by FeSO4. Subsequently, Cr(III), Fe(II) and Fe(III) were hydrothermally mineralized to form the magnetic spinel phase Fe2+(Cr3+X, Fe3+2-x)O4 (FeCr spinel substance), which was conducive to the magnetic separation of ferrochrome resources. Under the optimal hydrothermal conditions (0.15 g FeSO4/2 g COPR, treatment at 180 °C for 8 h), the total Cr leaching concentration of treated COPR (COPR-HT) was decreased from 120.51 mg L-1 to 0.23 mg L-1, well below the regulatory limit of 1.5 mg L-1 (HJ/T 301-2007, China EPA). After 300 days aging under atmospheric conditions, the total Cr leaching concentration of COPR-HT was still below 1.5 mg L-1. Besides, the COPR-HT after magnetic separation contained 11.52 wt% Cr2O3 and 53.44 wt% Fe2O3, which can be used as the raw material for steel industry. The underlying mechanism of COPR stabilization was explained by XRD, XPS and SEM-EDS analysis. This work converted the toxic and unstable Cr(VI) in COPR into the long-term stable FeCr spinel substance that is easy to magnetically separate. It has important reference for the harmless disposal and resource utilization of other chromium-containing hazardous wastes including chromium slag and electroplating sludge.

3.
J Colloid Interface Sci ; 608(Pt 2): 1837-1845, 2021 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-34742092

RESUMO

In this work, oxygen-defect-rich, three-dimensional (3D) cobalt-gallium layered double hydroxides (Co0.50-Ga0.50-LDH) assembled by porous and ultrathin nanosheets are prepared by a simple one-step strategy. Briefly, an aqueous solution containing Co2+ and Ga3+ is quickly pouring into the aqueous solution of hexamethylenetetramine, the state-of-the-art LDH was obtained followed by a mild and fast hydrothermal reaction. This mild and rapid synthesis strategy introduces a large number of pores into the ultrathin LDH nanosheets, resulting in a high concentration of oxygen vacancies in the Co0.50-Ga0.50-LDH, and the concentration of oxygen vacancies can be arbitrarily modulated, which has been corroborated by X-ray photoelectron spectroscopy and electron spin resonance measurements. The synergistic effect of the oxygen vacancy and the introduced Ga ions in the LDH nanosheets enhances the adsorption of the LDH nanosheets on OH-, endowing Co0.50-Ga0.50-LDH with outstanding performance for the supercapacitor application. Co0.50-Ga0.50-LDH offers a high specific capacity (0.62C·cm-2) at 10 mV·s-1 and extraordinary cycling stability. An aqueous asymmetric supercapacitor (ASC) constructed with Co0.50-Ga0.50-LDH and activated carbon (AC) materials exhibits high energy density and a long lifespan. This result encourages the wide application of porous ultrathin LDH nanosheets in energy storage, catalysis and light response.

4.
Chemosphere ; 285: 131439, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34246932

RESUMO

A facile pyrolysis-quenching-reroasting process was developed to prepare a sludge-based biochar adsorbent, and its adsorption performance for Cr(VI) ions was investigated. The unquenched biochar (U-BC) and quenched biochar (Q-BC) were systematically compared and characterized. Fourier transform infrared spectroscopy (FTIR) results showed that more carbon and oxygen functional groups such as -COOH and -OH were formed on the surface of Q-BC. These functional groups could be used as active sites during the adsorption process and help to improve the adsorption performance of the material. The results of Brunauer-Emmett-Teller (BET) analysis showed that the specific surface area of U-BC biochar was 523.36 m2/g, while the specific surface area of Q-BC biochar after quenching treatment increased to 785.3 m2/g. The adsorption performance of Q-BC biochar was studied, and the effects of pH, contact time and temperature on the adsorption performance of the material were explored. The pseudo-second-order model and Langmuir isotherm model indicated that the removal of Cr(VI) by Q-BC biochar material was a chemical adsorption-based adsorption process. At a temperature of 298 K and a pH of 1, the maximum Cr(VI) adsorption capacity of the quenched Q-BC biochar is as high as 291.54 mg/g, which was much higher than the maximum adsorption capacity of U-BC biochar (91.46 mg/g). This pyrolysis-quenching-reroasting process to prepare modified biochar provides a new, economical and effective way for the preparation of high-performance adsorption materials from municipal sludge.


Assuntos
Esgotos , Poluentes Químicos da Água , Adsorção , Carvão Vegetal , Cromo/análise , Cinética , Poluentes Químicos da Água/análise
5.
J Hazard Mater ; 420: 126605, 2021 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-34329110

RESUMO

Sulfidated nanoscale zero-valent iron (S-nZVI) has shown excellent removal capacity for the removal of cadmium (Cd) in aqueous phase. Herein, the effectiveness and the mechanism of S-nZVI for the remediation of Cd contaminated soil were investigated for the first time. The results of sequential extraction procedures (SEP) showed that the exchangeable (EX) Cd was decreased by over 97.6% at the optimal dosage of 5 g kg-1 S-nZVI during 30 d incubation and converted to less available Cd such as iron-manganese oxides-bound (OX) and organic matter-bound (OM) fractions. pH has negligible effect on the immobilization of Cd in soil, since OX fraction was stabilized in the range of 72-92% at initial soil pH range from 5.3 to 7.5. SEM-EDS analysis of the separated magnetic particles implied that Cd was successfully enriched on S-nZVI and the distribution of Cd was closely related to Fe, S, and O. CdO and CdS was confirmed as the key products for Cd immobilization in soil. Meanwhile, the S-nZVI was oxided to α-FeOOH, γ-FeOOH, and γ-Fe2O3. The existence of CdO was visibly related to the iron oxides, suggesting the synergetic immobilization effect by iron oxides. Overall, S-nZVI was promising for the remediation of Cd-contaminated soil.


Assuntos
Recuperação e Remediação Ambiental , Poluentes do Solo , Cádmio/análise , Ferro/análise , Solo , Poluentes do Solo/análise
6.
Environ Sci Pollut Res Int ; 28(41): 57695-57705, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34091839

RESUMO

Sewage sludge (SS) dewatering is a key step in sludge disposal, which plays an important role in reducing sludge volume, facilitating transportation and subsequent treatment. In this paper, a facile hydrothermal-alkaline treatment for SS was proposed, which can be used for sludge dewatering and humic acid (HA) recycling at the same time. Response surface methodology (RSM) was used to determine the optimal conditions, and a mathematical model was established to accurately predict the changes of sludge water content and the extraction rate of HA. Under the optimal conditions of 170 °C/42 min/0.05 (for hydrothermal temperature, hydrothermal time, and mass ratio of KOH to wet sludge, respectively), the water content decreased to 46.7% and the extraction rate of HA (with a purity of 96.2%) was 89.1%. The improvement of the dewatering performance effectively facilitates the subsequent disposal of the sludge. The hydrothermal-alkaline method not only realizes the efficient dehydration of the sludge, but also obtains HA from the sludge extract. The obtained HA has potential economic value in the fields of agriculture, biological medicine, environment, and the like.


Assuntos
Esgotos , Eliminação de Resíduos Líquidos , Substâncias Húmicas , Temperatura , Água
7.
Chemosphere ; 275: 130008, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33984913

RESUMO

Coal gangue (CG) is one of the largest industrial solid wastes in the world produced during the process of coal mining. The accumulation of CG is easy to cause ion leakage, which is harmful to the environment and human body. The recovery and utilization of CG are imminent. In the process, a hierarchical porous carbon (HPC) adsorbent with excellent adsorption property for Cr(VI) and rhodamine B (RhB), was prepared from CG by a two-step method and characterized by SEM, TEM, XRD, XPS, TPD and BET. The results revealed that the specific surface area of HPC is up to 2012.7 m2 g-1, and its adsorption capacities for Cr(VI) and RhB are reached 320.51 and 3086.42 mg g-1. The adsorption mechanism of RhB was the synergetic effect of physics and chemistry. While XPS results suggested that hierarchical porous carbons (HPCs) only have a chemisorption effect on Cr(VI). This study provided an idea for the preparation of HPCs from CG to remove inorganic and organic pollutants such as heavy metal Cr(VI) and RhB in water.


Assuntos
Carbono , Poluentes Químicos da Água , Adsorção , Cromo , Carvão Mineral , Humanos , Concentração de Íons de Hidrogênio , Cinética , Porosidade , Rodaminas , Poluentes Químicos da Água/análise
8.
J Hazard Mater ; 404(Pt B): 124113, 2021 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-33068998

RESUMO

This work demonstrated that electroplating sludges (EPS) of specific composition may be used for the synthesis of layered double hydroxide (LDH) materials for energy applications after appropriate treatment. The unique composition and structure of EPS render it with good electrochemical energy storage performance. The EPS containing Ni, Fe, and Al was dissolved by acid and added with urea precipitator. The LDH material was prepared by a facile hydrothermal method. The increase of urea in a certain range is conducive to the formation of intact LDH. However excessive urea levels promoted the transformation from LDH to Ni(HCO3)2. Various active Ni bridged by N in ‒O‒CN promoted electron transfer, ‒O‒CN content in LDHs was proportional to the urea amount. The prepared LDHs exhibited a specific capacitance of 1652.20 F g-1 at 0.5 A g-1, and the value remained at 766.69 F g-1 after 1000 cycles. The prepared LDH has excellent supercapacitor performance, which is closely related to its structure. Therefore, the proposed recycling strategy of EPS resources can be used to prepare LDH supercapacitors, paving the way for new applications of EPS in the field of energy storage.

9.
J Mol Graph Model ; 103: 107806, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33248340

RESUMO

Selective, reversible and tailored adsorption of CO2 from gas mixture is always demanded to control global warming. We for the first time used P-decorated C24N24 fullerene for selective separation of CO2 from N2/CO2 mixture in the presence of an electric field by using density functional theory methods. The computed geometrical parameters evince that the binding distances and bond angles (OCO) are remarkably reduced in electric field and that transformed the physisorption to chemisorption by increasing the field from 0.012 to 0.013 au. The adsorption/desorption of CO2 over the substrate can be easily controlled by switching on and off the electric field. This study reveals that P@C24N24 is a selective adsorbent of CO2 from N2/CO2 mixture and will help the future synthesis of selective, controllable and regenerable adsorbent for the CO2 separation from gas mixture in presence of electric field.


Assuntos
Fulerenos , Adsorção , Dióxido de Carbono , Eletricidade , Gases
10.
Nanoscale ; 13(2): 901-911, 2021 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-33367362

RESUMO

Photocatalytic hydrogen production from water is a promising method to obtain clean energy in the future. In this work, the sulfated TiO2 photocatalyst is successfully constructed in situ via a soft-templated method for photocatalytic water splitting to produce hydrogen. The content of sulfate species in TiO2 can be tuned by changing the amount of the surfactant. The photocatalyst with the appropriate content of sulfate ions exhibits an apparent quantum efficiency (AQE) of 3.9% at 365 nm and a high hydrogen production rate of 24.32 mmol h-1 g-1, which is 1.65 times that of commercial TiO2 (P25). The optimized photocatalyst has excellent photocatalytic activity for hydrogen evolution benefitting from the presence of sulfate ions on the surface of TiO2, large surface area and oxygen vacancies, which facilitates the rapid migration of photo-generated electrons to its surface and the improvement of the separation efficiency of photo-generated carriers. This work may inspire the rational design and the development of high-efficiency photocatalysts.

11.
J Hazard Mater ; 403: 123870, 2021 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-33264942

RESUMO

Nanosized clay minerals have been widely used as efficient supports to immobilize catalyst nanoparticles. However, clay support-induced interactions and their influences on the catalyst structure and performance currently have not been fully understood. Here, Co3O4 nanoparticles supported on halloysite nanotubes (HNTs) were synthesized by a facile deposition-precipitation approach followed by thermal treatment. A series of characterization methods were employed for the Co3O4/HNTs hybrid nanostructure to identify its crystal phase, chemical composition, morphology, specific surface area, surface chemical states, and redox property. Characterization results showed that HNTs not only impacted the particle size of Co3O4 nanoparticles, but also modified surface chemical surface states of the later, which ultimately promoted the effective catalytic reduction of 4-nitrophenol (4-NP) and azo dyes with sodium borohydride. The interaction between HNTs and Co3O4 nanoparticles was found to shorten the induction period of the 4-NP reduction. Meanwhile, the Co3O4/HNTs catalyst for the 4-NP reduction achieved an apparent rate constant of 0.265 min-1 and an activity parameter of 1.63 × 104 min-1 g-1 as well as a turnover frequency of 4.37 min-1. In addition, Co3O4/HNTs showed an improvement in reduction efficiency of the azo dyes when compared to bare Co3O4 nanoparticles.

12.
J Hazard Mater ; 404(Pt A): 124057, 2021 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-33022528

RESUMO

In this study, the reaction between sulfidated nanoscale zero-valent iron (S-nZVI) and heavy metal cations as well as the role of sulfur were investigated. The results showed the corrosion products of S-nZVI were lepidocrocite (γ-FeOOH) or/and magnetite (Fe3O4), depending on heavy metal species. While the removal of Hg(II), Ag(I), Cu(II), and Pb(II) by S-nZVI was rapid and could achieve over 99% within 5 mins, the removal of Ni(II) and Zn(II) was low in efficiency and unstable. Sulfur was existed as iron sulfides at fresh S-nZVI, but was displaced by the heavy metals and formed the related sulfide compound, or oxidized to S0 and SO42-. The removal mechanisms are strongly dependent on the solubility product constant (Ksp) of metal sulfides. For Hg(II) and Ag(I), with Ksp of corresponding metal sulfides much lower than that of iron sulfide, the removal mechanism is the displacement reaction. For Cu(II) and Pb(II), with Ksp of corresponding metal sulfides moderately lower than that of iron sulfide, the removal mechanisms are the displacement reaction and complexation with surface groups of S-nZVI. For Zn(II) and Ni(II), whose Ksp of corresponding metal sulfides slightly lower than that of iron sulfide, are mainly removed by complexation with surface groups of S-nZVI.

13.
ACS Appl Mater Interfaces ; 12(36): 40204-40212, 2020 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-32794688

RESUMO

Electro- and photocatalytic hydrogen evolution reaction (e-HER and p-HER) are two promising strategies to produce green hydrogen fuel from water. High intrinsic activity, sufficient active sites, fast charge-transfer capacity, and good optoelectronic properties must be taken into consideration simultaneously in pursuit of an ideal bifunctional catalyst. Here, platinum atomic clusters embedded in defects of TiO2 nanocrystals/graphene nanosheets (Pt-T/G) are reported as a bifunctional catalyst for electro- and photocatalytic hydrogen evolution reaction (e-HER and p-HER). High activity is delivered due to the charge transfer from the other part of the catalyst to the active center (Pt2-O4-Tix), decreasing the activation energy of the rate-limiting step, which is revealed by synchrotron X-ray absorption spectroscopy, photoelectrochemical measurements, and simulated calculations. In regard to e-HER, it outperforms the commercial 20 wt % Pt/C catalyst by a factor of 17.5 on Pt mass basis, allowing for a 93% reduction in Pt loadings. In regard to p-HER, it achieves photocatalytic efficiency (686.8 µmol h-1) without any attenuation in 9 h.

14.
ACS Omega ; 5(27): 16789-16795, 2020 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-32685847

RESUMO

Iron-supported catalysts exhibit good catalytic performance in direct coal liquefaction (DCL), but the effect of the carrier on the performance of the composite catalyst is unclear. In this paper, a simple solid-state synthesis strategy for the preparation of coal-loaded Fe3O4 nanoparticles (Fe3O4/Coal) and the hydrochloric acid treatment of coal-loaded Fe3O4 nanoparticles (Fe3O4/Coal-HCl) is presented. The resulting composite was used as a catalyst for DCL. The effects of supports on the structure and performance of iron-supported catalysts have been illustrated. After the acid pretreatment of the catalyst carrier coal, the surface structure and functional groups changed, which affected the aggregation morphology of the Fe3O4 active component. The Fe3O4/Coal-HCl catalyst improved the catalytic performance of DCL with conversion and oil yield of 98.02 and 49.96 wt %, respectively. The result shows that pretreatment can be an effective way to modify the surface of the catalyst carrier coals, thereby further improving the catalytic performance of composites. The iron-based composites prepared by the solid-state route show great potential as supported catalysts in DCL.

15.
J Colloid Interface Sci ; 579: 195-204, 2020 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-32590160

RESUMO

Single imidazolate framework-67 (ZIF-67) is commonly used as a template to prepare layered double hydroxides (LDHs) with specific morphology to improve the performance of materials. Herein, the Co2+ ion in ZIF-67 is partially substituted by Ni2+ to obtain the dodecahedron bimetallic imidazolate framework (CoNi-ZIF). Subsequently, using bimetallic CoNi-ZIF as the sacrificial template, CoNi-LDH hierarchical hollow cage structures with wrinkled nanosheet arrays are synthesized at room temperature and in aqueous solution by an inexpensive and environment friendly surfactant-free approach. The optimized etched CoNi-LDH4 has a maximum specific capacitance of 1877 F g-1 at a current density of 1 A g-1, and cycling stability of 99.89% after 5000 cycles, which is significantly better than that of ZIF-67 derived CoNi-LDH67 (1357 F g-1 at 1 A g-1, cycling stability of 73.35%). The asymmetric supercapacitor with CoNi-LDH4 as a cathode and activated carbon (AC) as anode has an energy density of 49.3 Wh kg-1 at 750 W kg-1 power output and stable cycling performance (capacity retention of 92.13% after 5000 cycles). This study shows the prospect of bimetallic CoNi-ZIF derived LDHs nanostructures prepared at room temperature and in aqueous solution to improve the performance and stability of supercapacitors.

16.
Environ Pollut ; 263(Pt B): 114374, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32298933

RESUMO

Porous carbon, which can be functionalized, is considered as a potential carbon material. Herein, two-dimensional (2D) nitrogen-doped magnetic Fe3C/C (NMC) was prepared by a simple carbonization method using potassium humate (HA-K) as raw material. Remarkably, two templates, g-C3N4 and KCl, were formed in situ during the carbonization process, which provide the necessary conditions for the formation of 2D NMC. The NMC was comprehensively studied by different characterization methods. The results show that NMC has a large surface area and mesoporous structure. The prepared NMC-0.50 was used to test the removal performance of Cr(VI). The effects of pH value, coexisting ions and time on Cr(VI) removal performance were investigated, and the adsorption kinetics, isotherm and thermodynamics were studied. The results showed that the adsorption isotherm model of NMC-50 accorded with the Langmuir model, and the maximum adsorption capacity was 423.73 mg g-1. The reaction mechanism of Cr(VI) is adsorption and redox reaction. In addition, NMC-0.50 exhibit high selectivity, separability and regeneration performance. A convenient means for the synthesis of NMC was designed in this work, and demonstrate that NMC has practical value as an adsorbent.


Assuntos
Nitrogênio , Poluentes Químicos da Água/análise , Adsorção , Cromo/análise , Cinética , Fenômenos Magnéticos
17.
J Nanosci Nanotechnol ; 20(2): 769-778, 2020 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-31383072

RESUMO

A super absorbent was synthesized from calcium-aluminum waste residue of aluminum industrial using a facile hydrothermal method. The XRD results revealed that the main phase of hydrothermal product at 120 °C is CaSO4 ·2H2O, with a small amount of Al(OH)3. The as-prepared products were used to investigate the adsorptive applications in Congo red (CR) removal, and the results showed that the products treated at 120 °C had the best adsorption properties. The maximum adsorption capacity reaches about 1860.11 mg/g with a removal rate of 99.75%. Furthermore, the used adsorbent could be regenerated for at least four cycles through a calcination procedure, indicating its potential as an excellent adsorbent for the removal of CR dye from wastewater. The adsorption behavior was analyzed by Langmuir, Freundlich and Sips isotherms, and the adsorption proved to be a multilayer adsorption. This facile method presented here may provide promise synthesis of high-effective and low-cost adsorbents from industrial solid waste and achieve the goal of "using waste to treat waste" in the future.

18.
J Colloid Interface Sci ; 557: 311-317, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31525668

RESUMO

Ultrafine WO3-x (0 < x < 1) nanowires with aspect ratio greater than 100 were successfully synthesized by two-phase strategy. The crystal structure, morphology evolution and thermal stability of the samples were characterized by X-ray diffractometer (XRD), X-ray photoelectron spectrum (XPS), high resolution transmission electron microscopy (HRTEM), and thermal gravimetric analysis (TGA). The morphology of WO3-x nanowires is closely related to the pH value and oleamine content of the reaction system. By controlling the reaction conditions, a linear product with a diameter of less than 2 nm can be obtained, and the exposed active lattice plane is 110 crystal face. On this basis, the prepared ultrafine WO3-x nanowire sensor was tested for a series of harmful gases. The sensitivity of WO3-x-based gas sensors can reach 57.9 for 10 ppm NO2 at 100 °C, which is much higher than most reported values. The sensor has the excellent sensing performance of ppm NO2 at low operating temperature, which is due to its nanowire structure and oxygen vacancies. These results demonstrate that this type of sensor is a competitive candidate for NO2-sensing applications.

19.
Environ Pollut ; 254(Pt A): 112961, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31398635

RESUMO

CoFe2O4/C nano-sheets (NSs) have been synthesized by a facile molten salt method using cheap potassium fulvate as carbon source and sodium chloride as template. The morphology, crystallinity and composition of the materials were analyzed by TEM, XRD and XPS. The study on the catalytic performance of 4-nitrophenol (4-NP) shows that CoFe2O4/C-600 nano-catalyst has the highest catalytic activity and the corresponding apparent constant is 1.91 min-1, this result is higher than that reported in most literatures. Catalytic kinetics of 4-NP reduction was studied in this article, and activation energy (Ea) was calculated to be 14.31 kJ mol-1. The catalyst also shows good cycle performance and stability. This convenient method provides a reference for the synthesis of MFe2O4/C and other nano-metal oxides/C nanocomposite catalysts.


Assuntos
Modelos Químicos , Nitrofenóis/química , Carbono , Catálise , Nanocompostos , Óxidos , Sais/química , Cloreto de Sódio
20.
Sensors (Basel) ; 19(5)2019 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-30871099

RESUMO

In this paper, WO3·0.33H2O nanorods were prepared through a simple hydrothermal method using p-aminobenzoic acid (PABA) as an auxiliary reagent. X-ray diffraction (XRD) and transmission electron microscopy (TEM) images showed that the products with PABA addition were orthorhombic WO3·0.33H2O, which were mainly composed of nanorods with different crystal planes. The sensing performance of WO3·0.33H2O nanorod bundles prepared by the addition of PABA (100 ppm cyclohexene, Ra/Rg = 50.6) was found to be better than the WO3 synthesized without PABA (100 ppm cyclohexene, Ra/Rg = 1.3) for the detection of cyclohexene. The new synthesis route and sensing characteristics of as-synthesized WO3·0.33H2O nanorods revealed a promising candidate for the preparation of the cost-effective gas sensors.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...