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1.
Mol Med ; 30(1): 41, 2024 Mar 22.
Artículo en Inglés | MEDLINE | ID: mdl-38519941

RESUMEN

BACKGROUND: Benign prostatic hyperplasia (BPH) is a prevalent disease affecting elderly men, with chronic inflammation being a critical factor in its development. Omentin-1, also known as intelectin-1 (ITLN-1), is an anti-inflammatory protein primarily found in the epithelial cells of the small intestine. This study aimed to investigate the potential of ITLN-1 in mitigating BPH by modulating local inflammation in the prostate gland. METHODS: Our investigation involved two in vivo experimental models. Firstly, ITLN-1 knockout mice (Itln-1-/-) were used to study the absence of ITLN-1 in BPH development. Secondly, a testosterone propionate (TP)-induced BPH mouse model was treated with an ITLN-1 overexpressing adenovirus. We assessed BPH severity using prostate weight index and histological analysis, including H&E staining, immunohistochemistry, and enzyme-linked immunosorbent assay. In vitro, the impact of ITLN-1 on BPH-1 cell proliferation and inflammatory response was evaluated using cell proliferation assays and enzyme-linked immunosorbent assay. RESULTS: In vivo, Itln-1-/- mice exhibited elevated prostate weight index, enlarged lumen area, and higher TNF-α levels compared to wild-type littermates. In contrast, ITLN-1 overexpression in TP-induced BPH mice resulted in reduced prostate weight index, lumen area, and TNF-α levels. In vitro studies indicated that ITLN-1 suppressed the proliferation of prostate epithelial cells and reduced TNF-α production in macrophages, suggesting a mechanism involving the inhibition of macrophage-mediated inflammation. CONCLUSION: The study demonstrates that ITLN-1 plays a significant role in inhibiting the development of BPH by reducing local inflammation in the prostate gland. These findings highlight the potential of ITLN-1 as a therapeutic target in the management of BPH.


Asunto(s)
Hiperplasia Prostática , Humanos , Masculino , Ratones , Animales , Anciano , Hiperplasia Prostática/genética , Hiperplasia Prostática/tratamiento farmacológico , Hiperplasia Prostática/metabolismo , Factor de Necrosis Tumoral alfa , Extractos Vegetales/farmacología , Próstata/metabolismo , Próstata/patología , Inflamación/patología
2.
Langmuir ; 40(17): 9144-9154, 2024 Apr 30.
Artículo en Inglés | MEDLINE | ID: mdl-38629776

RESUMEN

Wastewater pollutants are a major threat to natural resources, with antibiotics and heavy metals being common water contaminants. By harnessing clean, renewable solar energy, photocatalysis facilitates the synergistic removal of heavy metals and antibiotics. In this paper, MXene was both a template and raw material, and MXene-derived oxide (TiO2) and SnIn4S8 Z-scheme composite materials were synthesized and characterized. The synergistic mode of photocatalytic reduction and oxidation leads to the enhanced utilization of e-/h+ pairs. The TiO2/SnIn4S8 exhibited a higher photocatalytic capacity for the simultaneous removal of tetracycline (TC) (20 mg·L-1) and Cr(VI) (15 mg·L-1). The main active substances of TC degradation and Cr(VI) reduction were identified via free radical scavengers and electron paramagnetic resonance (EPR). Additionally, the potential photocatalytic degradation route of TC was thoroughly elucidated through liquid chromatography-mass spectrometry (LC-MS).

3.
Opt Express ; 30(10): 16748-16757, 2022 May 09.
Artículo en Inglés | MEDLINE | ID: mdl-36221511

RESUMEN

We demonstrate the three-photon Autler-Townes (AT) spectroscopy in a cold cesium Rydberg four-level atom by detecting the field ionized Rydberg population. The ground state |6S1/2〉, two intermediate states |6P3/2〉 and |7S1/2〉 and Rydberg state |60P3/2〉 form a cascade four-level atomic system. The three-photon AT spectra and AT splittings are characterized by the Rabi frequency Ω852 and Ω1470 and detuning δ852 of the coupling lasers. Due to the interaction of two coupling lasers with the atoms, the AT spectrum has three peaks denoted with the letters A, B and C. Positions of the peaks and relative AT splittings, γAB and γBC, strongly depend on two coupling lasers. The dependence of the AT splitting, γAB and γBC, on the coupling laser detuning, δ852, and Rabi frequency, Ω852 and Ω1470 are investigated. It is found that the AT splitting γAB mainly comes from the first photon coupling, whereas the γBC mainly comes from the second photon coupling with the atom. The three-photon AT spectra and relevant AT splittings are simulated with the four-level density matrix equation and show good agreement with the theoretical simulations considering the spectral line broadening. Our work is of great significance both for further understanding the interaction between the laser and the atom, and for the application of the Rydberg atom based field measurement.

4.
Inorg Chem ; 59(2): 1364-1375, 2020 Jan 21.
Artículo en Inglés | MEDLINE | ID: mdl-31904943

RESUMEN

Metal nanoparticles (NPs) have been deemed an imperative sector of nanomaterial for triggering the Schottky-junction-driven electron flow in photoredox catalysis, but they suffer from sluggish charge-transfer kinetics, rendering efficient charge flow difficult. Here, we report the construction of unidirectional charge-transfer channel in a metal/semiconductor heterostructure via a ligand-triggered self-assembly method, by which hierarchically branched ligands (DMAP)-capped Pd NPs were controllably attached on the WO3 nanorods (NRs) scaffold, resulting in the well-defined Pd@DMAP/WO3 NRs heterostructures. The pinpointed deposition of Pd@DMAP on the WO3 NRs endows the Pd@DMAP/WO3 NRs heterostructure with conspicuously improved photoactivities for organic pollutant mineralization, as well as the capacities for photocatalytic selective oxidation of aromatic alcohols to aldehydes and photoreduction of chromium ions under the irradiation of simulated sunlight and visible light, far surpassing the applicability of blank WO3 NRs. This is due to the imperative contribution of Pd@DMAP as efficient electron reservoir in accelerating the unidirectional flow of electrons from Pd@DMAP to WO3 NRs, overcoming the confinement of spatially hierarchically branched ligand and interface configuration. Moreover, interfacial charge transport efficiency is finely tuned by the interface configuration engineering. The active species in the multifarious photoreactions were unveiled, and a linker-triggered photoredox catalysis mechanism was put forward. It is hoped that our current work would afford new strategies for strategically constructing metal/semiconductor heterostructures for versatile photocatalytic applications.

5.
Inorg Chem ; 59(6): 4129-4139, 2020 Mar 16.
Artículo en Inglés | MEDLINE | ID: mdl-32141289

RESUMEN

The capability of noble metal nanoparticles (NPs) as efficient charge transfer mediators to stimulate Schottky-junction-triggered charge flow in multifarious photocatalysis has garnered enormous attention in the past decade. Nevertheless, fine-tuning and controllable fabrication of a directional charge transport channel in metal/semiconductor heterostructures via suitable interface engineering is poorly investigated. Here, we report the progressive fabrication of a tailor-made directional charge transfer channel in Pt nanoparticles (NPs)-inlaid WO3 (Pt-WO3) nanocomposites via an efficient electrostatic layer-by-layer (LbL) self-assembly integrated with a thermal reduction treatment, by which oppositely charged metal precursor ions and polyelectrolyte building blocks were intimately and alternately assembled on the WO3 nanorods (NRs) by substantial electrostatic interaction. LbL self-assembly buildup and in situ self-etching-induced structural variation of WO3 NRs to a microsized superstructure occur simultaneously. We found that such exquisitely crafted Pt-WO3 nanocomposites exhibit conspicuously enhanced and versatile photoactivities for nonselective mineralizing of organic dye pollution and reduction of heavy metal ions at ambient conditions under both visible and simulated sunlight irradiation, demonstrating a synergistic effect. This is attributed to the imperative contribution of Pt NPs as electron traps to accelerate the directional high-efficiency electron transport from WO3 to Pt NPs, surpassing the confinement of electron transfer kinetics of WO3 owing to low conduction level. More intriguingly, photoredox catalysis can also be triggered simultaneously in the same reaction system. The primary in situ produced active species in the photocatalytic reactions were specifically analyzed, and underlying photocatalytic mechanisms were determined. Our work would provide a universal synthesis strategy for constructing various metal-decorated semiconductor nanocomposites for widespread photocatalytic utilizations.

6.
Macromol Rapid Commun ; 36(20): 1799-805, 2015 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-26292975

RESUMEN

Covalent triazine-based frameworks (CTFs) with a graphene-like layered morphology have been controllably synthesized by the trifluoromethanesulfonic acid-catalyzed nitrile trimerization reactions at room temperature via selecting different monomers. Platinum nanoparticles are well dispersed in CTF-T1, which is ascribed to the synergistic effects of the coordination of triazine moieties and the nanoscale confinement effect of CTFs. CTF-T1 exhibits excellent photocatalytic activity and stability for H2 evolution in the presence of platinum under visible light irradiation (λ ≥ 420 nm). The activity and stability of CTF-T1 are comparable to those of g-C3 N4 . Importantly, as a result of the tailorable electronic and spatial structures of CTFs that can be achieved through the judicial selection of monomers, CTFs not only show great potential as organic semiconductor for photocatalysis but also may provide a molecular-level understanding of the inherent heterogeneous photocatalysis.


Asunto(s)
Triazinas/química , Agua/química , Catálisis , Técnicas Electroquímicas , Grafito/química , Hidrógeno/química , Oxidación-Reducción , Oxígeno/química , Procesos Fotoquímicos , Rayos Ultravioleta
7.
Int Urol Nephrol ; 2024 Apr 02.
Artículo en Inglés | MEDLINE | ID: mdl-38564076

RESUMEN

BACKGROUND: This research aimed to explore the association between changes in the intake of common individual vitamins and combinations of vitamins and the prevalence of kidney calculi. METHODS: We used data from NHANES to investigate the association between nine common vitamins and kidney stone prevalence. Participants were clustered into several vitamin exposure patterns using an unsupervised K-means clustering method. We used logistic regression models and restrictive cubic spline curves to explore the influence of vitamins. RESULTS: The regression model exposed that compared to lower intake, high intake of vitamin B6 [Q4: OR (95% CI) = 0.76 (0.62, 0.93)], vitamin C [Q4: OR (95% CI) = 0.73 (0.59, 0.90)] and vitamin D [Q4: OR (95% CI) = 0.77 (0.64, 0.94)] individually exerted protective effects against the prevalence of kidney stones. Furthermore, the restrictive cubic spline analysis showed that the protective effect against the prevalence of kidney stones is enhanced as the take of vitamin B6 and vitamin D increased. Moreover, with the increase in vitamin C intake, its protective effect may turn into a risk factor. Regarding mixed exposure, Cluster 4 exhibited a significant protective effect against kidney stones compared with Cluster 1 [Model 3: OR (95% CI) = 0.79 (0.64, 0.98)]. CONCLUSIONS: Our research revealed that high levels of vitamin B6 and vitamin D intake were linked to a lower prevalence of kidney stone. With the gradual increase intake of vitamin C, the prevalence of kidney calculi decreased first and then increased. In addition, the co-exposure of nine vitamins is a protective factor for kidney stone disease.

8.
J Colloid Interface Sci ; 643: 102-114, 2023 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-37054545

RESUMEN

Covalent organic frameworks (COFs) are crystalline porous materials with enormous potential for realizing solar-driven CO2-to-fuel conversion, yet the sluggish transfer/separation of photoinduced electrons and holes remains a compelling challenge. Herein, a step (S)-scheme heterojunction photocatalyst (CuWO4-COF) was rationally fabricated by a thermal annealing method for boosting CO2 conversion to CO. The optimal CuWO4/COF composite sample, integrating 10 wt% CuWO4 with an olefin (C═C) linked COF (TTCOF), achieved a remarkable gas-solid phase CO yield as high as 7.17 ± 0.35 µmol g-1h-1 under visible light irradiation, which was significantly higher than the pure COF (1.6 ± 0.29 µmol g-1h-1). The enhanced CO2 conversion rate could be attributable to the interface engineering effect and the formation of internal electric field (IEF) directing from TTCOF to CuWO4 according to the theoretical calculation and experimental results, which also proves the electrons transfer from TTCOF to CuWO4 upon hybridization. In addition, driven by the IEF, the photoinduced electrons can be steered from CuWO4 to TTCOF under visible light irradiation as well-elucidated by in-situ irradiated X-ray photoelectron spectroscopy, verifying the S-scheme charge transfer pathway over CuWO4/COF composite heterojunctions, which greatly foster the photoreduction activity of CO2. The preparation technique of the S-scheme heterojunction photocatalyst in this study provides a paradigmatic protocol for photocatalytic solar fuel generation.

9.
Nanomaterials (Basel) ; 12(23)2022 Nov 22.
Artículo en Inglés | MEDLINE | ID: mdl-36500734

RESUMEN

Photocatalysis offers a sustainable approach for recalcitrant organic pollutants degradation, yet it is still challenging to seek robust photocatalysts for application purposes. Herein, a novel NiFe layered double hydroxide (LDH)/covalent triazine framework (CTF-1) Z-scheme heterojunction photocatalyst was rationally designed for antibiotics degradation under visible light irradiation. The NiFe-LDH/CTF-1 nanocomposites were readily obtained via in situ loading of NiFe-LDH on CTF-1 through covalent linking. The abundant coupling interfaces between two semiconductor counterparts lay the foundation for the formation of Z-scheme heterostructure, thereby effectively promoting the transfer of photogenerated electrons, inhibiting the recombination of carriers, as well as conferring the nanocomposites with stronger redox ability. Consequently, the optimal photocatalytic activity of the LDH/CTF heterojunction was significantly boosted for the degradation of a typical antibiotic, tetracycline (TC). Additionally, the photodegradation process and the mineralization of TC were further elucidated. These results envision that the LDH/CTF-1 can be a viable photocatalyst for long-term and sustainable wastewater treatment.

10.
Nanotechnology ; 22(46): 465101, 2011 Nov 18.
Artículo en Inglés | MEDLINE | ID: mdl-22024607

RESUMEN

Four different gold nanoparticle (GNP) preparations, including naked GNPs and GNPs coated either with thiolated undecane (S-C(11)H(23)), or with dithiolated diethylenetriaminepentaacetic (DTDTPA) or gadolinium (Gd) DTDTPA chelating agents, were synthesized. The average diameters, for each type of nanoparticle, are 5 nm, 10 and 13 nm, respectively. Dry films of plasmid DNA pGEM-3Zf(-), DNA with bound GNPs and DNA with coated GNPs were bombarded with 60 keV electrons. The yields of single and double strand breaks were measured as a function of exposure by electrophoresis. The binding of just one GNP without coating to DNA containing 3197 base pairs increases single and double strand breaks by a factor of 2.3 while for GNPs coated with S-C(11)H(23) this factor is reduced to 1.6. The GNPs coated with DTDTPA and DTDTPA:Gd in the same ratio with the DNA, produce essentially no increment in damage. These results could be explained by the attenuation by the coatings of the intensity of the low-energy photoelectrons emitted from the GNPs. Thus, coatings of GNPs may considerably attenuate the short-range low-energy electrons emitted from gold, leading to a considerable decrease of radiosensitization. According to our results, the highest radiosensitization should be obtained with GNPs having the shortest possible ligand, directed to the DNA of cancer cells.


Asunto(s)
ADN/metabolismo , Electrones , Oro/química , Oro/farmacología , Nanopartículas/química , Fármacos Sensibilizantes a Radiaciones/química , Fármacos Sensibilizantes a Radiaciones/farmacología , Quelantes/química , Quelantes/farmacología , Roturas del ADN/efectos de los fármacos , Gadolinio/química , Gadolinio/farmacología , Nanopartículas/ultraestructura , Plásmidos/efectos de los fármacos , Compuestos de Sulfhidrilo/química , Compuestos de Sulfhidrilo/farmacología
11.
Nanotechnology ; 21(35): 355601, 2010 Sep 03.
Artículo en Inglés | MEDLINE | ID: mdl-20683143

RESUMEN

GaOOH nanorods were synthesized from Ga(NO(3))(3) via a facile microwave hydrothermal method. The obtained sample was characterized by x-ray diffraction, N(2) sorption-desorption, UV-vis diffuse reflectance spectroscopy, transmission electron microscopy, electron spin resonance, and x-ray photoelectron spectroscopy. The results revealed that the as-synthesized sample was consisted of rod-like particles. It possessed a surface area of 14.3 m(2) g(-1), and a band gap of 4.75 eV. The photocatalytic property of GaOOH nanorods was evaluated by the degradation of aromatic compounds (such as benzene and toluene) in an O(2) gas stream under ultraviolet (UV) light illumination. The results demonstrated that GaOOH nanorods exhibited superior photocatalytic activity and stability as compared to commercial TiO(2) (P25, Degussa Co.) in both benzene and toluene degradation. In the extended (35 h) reaction test toward benzene, GaOOH maintained a high activity, and no obvious deactivation was observed. A possible mechanism of the photocatalysis over GaOOH is proposed.

12.
ACS Appl Mater Interfaces ; 12(4): 4373-4384, 2020 Jan 29.
Artículo en Inglés | MEDLINE | ID: mdl-31910618

RESUMEN

Finely tuning the charge transfer constitutes a central challenge in photocatalysis, yet exquisite control of the directional charge transfer to the target reactive sites is hindered by the rapid charge recombination. Herein, dual separated charge transport channels were fabricated in a one-dimensional transition-metal chalcogenide (TMC)-based system via an elaborate layer-by-layer (LbL) self-assembly approach, for which oppositely charged metal-ion-coordinated branched polyethylenimine (BPEI) and MoS2 quantum dots (QDs) were alternately integrated to fabricate the multilayered TMC@(BPEI/MoS2 QDs)n heterostructures with controllable interfaces. Photocatalytic hydrogen generation performances of such ternary heterostructures under visible light irradiation were evaluated, which unravels that the BPEI layer not only behaves as "molecule glue" to enable the electrostatic LbL assembly with MoS2 QDs in an alternate stacking fashion on the TMC frameworks but also acts as a unidirectional hole-transfer channel. More significantly, transition-metal ions (Fe2+, Co2+, Ni2+, Cu2+, and Zn2+) coordinated on the outmost BPEI layer are able to function as interfacial electron transfer mediators for accelerating the interfacial cascade electron transport efficiency. These simultaneously constructed dual high-speed electron and hole-transfer channels are beneficial for boosting the charge separation and enhancing the photocatalytic hydrogen evolution performances.

13.
J Colloid Interface Sci ; 535: 469-480, 2019 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-30321782

RESUMEN

Rational synthesis of photocatalytic materials is an effective way to improve their performance. In this work, to optimize the S precursors, a series of MnxCd1-xS (MCS) were first hydrothermally synthesized with the prevalent thiourea (TA), thioacetamide (TAA) and L-cysteine (L-Cys) as the S sources. The optimum feed ratio of Mn/Cd was then determined based on the optimized S precursor. The effects of S precursors and the feed ratio of Mn/Cd on the phase structure, absorption, morphology, band structure, and the photocatalytic hydrogen evolution reaction (HER) performance of MCS were investigated systematically. The hexagonal phase structures of MnS, CdS, and MCS are favored by TA and L-Cys as the S sources, while their cubic phases are benefited by TAA. TAA is the preferred S source for the preparation of highly active MCS and the solid solution is formed through the consolidation of cubic α-MnS into cubic CdS. The activity of MCS can be improved with the increase of Mn content from x = 0-0.6. The sample with x = 0.6 shows the highest HER activity (2253 µmol·h-1·g-1) and the performance is almost 6 times higher than CdS (416 µmol·h-1·g-1). The enhanced activity can be attributed to the improved separation efficiency of photo-induced charge carriers and the negative-shifts of Ecb, which are induced by the introduction of Mn. A segregation of inert α-MnS from MCS is occurred when Mn content is >0.6, resulting in a decay of the HER activity. A change of the semiconductivity from n-type to bipolar type is occurred in MCS due to the uneven sulfidation of Mn in MCS.

14.
Chem Commun (Camb) ; 55(71): 10591-10594, 2019 Aug 29.
Artículo en Inglés | MEDLINE | ID: mdl-31423497

RESUMEN

Glutathione-protected Aux nanoclusters uniformly and intimately embedded at the interface of CdSe QDs and graphene were in situ self-transformed to Au nanocrystals (NCs) via a facile thermal reduction strategy. The inlaid Au NPs substantially accelerate the interfacial directional charge transfer toward multifarious photoreduction catalysis under visible light irradiation.

15.
Inorg Chem ; 47(21): 9766-72, 2008 Nov 03.
Artículo en Inglés | MEDLINE | ID: mdl-18844343

RESUMEN

Porous ZnIn2S4 microspheres have been successfully synthesized by means of a facile thermal solution method at 353 K. This method was a simple route that involved low temperature, no templates, no catalysts, no surfactants, or organic solvents. Scanning electron microscopy, transmission electron microscopy, high-resolution transmission electron microscopy, X-ray diffraction, energy-dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, nitrogen sorption analysis, and a UV-vis spectrophotometer were used to characterize the products. The results demonstrated that the microspheres, which were composed of many ZnIn2S4 single crystal nanosheets, underwent the Oswald ripening and self-assembly processes. A morphology formation mechanism has been proposed and discussed. The porous ZnIn2S4 product showed an enhancing visible-light photocatalytic activity for methyl orange degradation. The as-grown architectures may have potential applications in solar energy conversion, environmental remediation, and advanced optical/electric nanodevices.

16.
J Colloid Interface Sci ; 514: 240-249, 2018 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-29274555

RESUMEN

In this manuscript, rod-like Bi4O7 decorated Bi2O2CO3 plates were fabricated for the first time. Compared with pristine Bi2O2CO3, the tight decoration of Bi4O7 over Bi2O2CO3 plates not only strengthened the visible light absorption, but also enhanced the separation efficiency of photo-generated carriers. As expected, the heterostructured Bi4O7/Bi2O2CO3 composites have exhibited highly promoted photocatalytic activities in decomposing Rhodamine B (RhB) under visible light. The BOBC-2 sample displayed the best activity with a reaction rate constant of 0.0245 min-1, which was 3.8 times higher than that of pure Bi4O7. Besides RhB, the Bi4O7/Bi2O2CO3 composites also displayed superior activity toward colorless contaminants with stable chemical structures, such as phenol, p-tert-butylphenol, and o-phenylphenol. The activity enhancement should be ascribed to the proper energy levels of the materials and formation of heterojunction at their interfaces, which could facilitate the charge transfer and promote the separation efficiency. Following transient photocurrent response, electrochemical impedance spectroscopy, and photoluminescence emission tests all verified this. In addition, controlled experiments using various radical scavengers proved that O2- and h+ played the chief role in decomposing organic pollutants. This work may provide a new method for constructing Bi-based heterostructured photocatalysts with high activity.

17.
J Colloid Interface Sci ; 501: 123-132, 2017 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-28448832

RESUMEN

In this work, highly efficient g-C3N4/Bi4O7 heterojunction photocatalysts have been successfully fabricated by a facile method. Compared with the bare photocatalysts, the obtained g-C3N4/Bi4O7 hybrid photocatalysts exhibited efficient degradation activity toward methylene blue (MB), phenol, rhodamine B (RhB), and bisphenol A (BPA) under visible light irradiation. The influences of different g-C3N4 contents on the photocatalytic efficiency of the hybrid photocatalysts have been investigated. The results revealed that the g-C3N4/Bi4O7 with g-C3N4 mass ratio of 30% exhibited the best photocatalytic activity. The activity enhancement should be ascribed to the improved visible light adsorption as well as the effective Z-scheme charge transfer according to the energy band theory. The UV-vis diffuse reflectance spectra (DRS) shows that the absorption edge of g-C3N4 move towards longer wavelength with the increment of Bi4O7 component. The strong connection between g-C3N4 and Bi4O7 was investigated using X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). Subsequently, the effective Z-scheme charge transfer has also been verified by using transient photocurrent measurements and electrochemical impedance spectroscopy. Controlled experiments proved that active species of O2- and h+ were produced in the degradation system, which played the major role in the degradation of MB. A possible Z-scheme degradation mechanism over g-C3N4/Bi4O7 hybrid photocatalysts was proposed.

18.
Environ Sci Technol ; 42(6): 2130-5, 2008 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-18409648

RESUMEN

The bifunctional photocatalyst Pt/TiO2-xNx has been successfully prepared by wet impregnation. The properties of Pt/ TiO2-xNx have been investigated by diffuse reflectance spectra, X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectroscopy, a photoluminescence technique with terephthalic acid, and electric field induced surface photovoltage spectra. The photocatalytic activity of the sample was evaluated by the decomposition of volatile organic pollutants (VOCs) in a H2-O2 atmosphere under visible light irradiation. The results demonstrated that nitrogen-doped and platinum-modified TiO2 in a H2-O2 atmosphere could enormously increase the quantum efficiency of the photocatalytic system with excellent photocatalytic activity and high catalytic stability. The increased quantum efficiency can be explained by enhanced separation efficiency of photogenerated electron-hole pairs, higher interface electron transfer rate, and an increased number of surface hydroxyl radicals in the photocatalytic process. A mechanism was proposed to elucidate the degradation of VOCs over PtTiO(2-x)Nx in a H2-O2 atmosphere under visible light irradiation.


Asunto(s)
Contaminantes Atmosféricos , Luz , Nitrógeno/química , Compuestos Orgánicos , Platino (Metal)/química , Titanio/química , Contaminantes Atmosféricos/química , Contaminantes Atmosféricos/efectos de la radiación , Catálisis , Hidrógeno/química , Compuestos Orgánicos/química , Compuestos Orgánicos/efectos de la radiación , Oxígeno/química , Fotoquímica , Volatilización
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