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1.
Heliyon ; 10(10): e31362, 2024 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-38813198

RESUMO

Lithium-ion batteries (LIBs) are promising secondary batteries that are widely used in portable electronic devices, electric vehicles and smart grids. The design and synthesis of high-performance electrode materials play a crucial role in achieving lithium-ion batteries with high energy density, prolonged cycle life, and superior safety. CoO has attracted significant attention as a negative electrode material for lithium-ion batteries due to its high theoretical capacity and abundant resources. However, its limited conductivity and suboptimal cycling performance impede its potential applications. The study proposes a novel micro-tube reaction method for the synthesis of Co@CoO/C, utilizing Kapok fiber as a template with a special hollow structure. The microstructure and composition of the samples were characterized using X-ray powder diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). After conducting electrochemical performance tests, it was discovered that at a current density of 100 mA/g and within the range of 0.01-3.0 V for 50 charge and discharge cycles. Co@CoO/C composite negative electrode exhibits a reversible lithium insertion specific capacity of 499.8 mAh/g and keep a discharge capacity retention rate of 97.6 %. The greatly improved lithium storage and stability performance of Co@CoO/C composite anode is mainly attributed to the synergistic effect between Co@CoO nanoparticles and the kapok carbon microtubule structure.

2.
Small ; 20(8): e2307547, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37814367

RESUMO

The sluggish four-electron oxygen evolving reaction is one of the key limitations of photoelectrochemical water decomposition. Optimizing the binding of active sites to oxygen in water and promoting the conversion of *O to *OOH are the key to enhancing oxygen evolution reaction. In this work, W-doped Cu2 V2 O7 (CVO) constructs corner-sharing tetrahedrally coordinated W-V dual active sites to induce the generation of electron deficiency active centers, promote the adsorption of ─OH, and accelerate the transformation of *O to *OOH for water splitting. The photocurrent obtained by the W-modified CVO photoanode is 0.97 mA cm-2 at 1.23 V versus RHE, which is much superior to that of the reported CVO. Experimental and theoretical results show that the excellent catalytic performance may be attributed to the formation of synergistic dual active sites between W and V atoms, and the introduction of W ions reduces the charge migration distance and prolongs the lifetime of photogenerated carriers. Meanwhile, the electronic structure in the center of the d-band is modulated, which leads to the redistribution of the electron density in CVO and lowers the energy barrier for the conversion of the rate-limiting step *O to *OOH.

3.
J Tradit Complement Med ; 13(6): 561-567, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-38020548

RESUMO

Objective: Baicalin, which is a key bioactive constituent obtained from Scutellaria baicalensis, has been utilized in traditional Chinese medicine for many centuries. Although it has been reported that Baicalin (BA) can inhibit the replication of the Hepatitis B virus (HBV), the exact mechanism behind this process remains unclear. Interferon-stimulated genes (ISGs) are crucial in the process of antiviral defense. We aim to investigate whether BA can regulate the expression of ISGs, and thereby potentially modulate the replication of HBV. Methods: The study involved the use of CRISPR/Cas9 technology to perform knockout experiments on TRIM25 and IFIT3 genes. The expression of these genes was confirmed through techniques such as immunoblotting or Q-PCR. The levels of HBsAg and HBeAg were measured using ELISA, and the expression of interferon-stimulated genes was detected using a luciferase assay. Results: It is interesting to note that several ISGs belonging to the TRIM family, including TRIM5, TRIM25, and TRIM14, were induced after BA treatment. On the other hand, members of the IFIT family were reduced by BA stimulation. Additionally, BA-mediated HBV inhibition was found to be significantly restored in HepG2 cells where TRIM25 was knocked out. Additional research into the mechanism of action of BA found that prolonged treatment with BA activated the JAK/STAT signaling pathway while simultaneously inhibiting the NF-kB pathway. Conclusion: The findings of our study indicate that TRIM25 has a significant impact on the regulation of HBV replication following BA treatment, providing additional insight into the mechanisms by which BA exerts its antiviral effects.

4.
Front Microbiol ; 13: 962186, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36118202

RESUMO

Hepatitis B virus (HBV) infection in humans and its associated diseases are long-standing problems. HBV can produce a large number of non-self-molecules during its life cycle, which acts as targets for innate immune recognition and initiation. Among these, interferon and its large number of downstream interferon-stimulated gene molecules are important early antiviral factors. However, the development of an effective antiviral immune response is not simple and depends not only on the delicate regulation of the immune response but also on the various mechanisms of virus-related immune escape and immune tolerance. Therefore, despite there being a relatively well-established consensus on the major pathways of the antiviral response and their component molecules, the complete clearance of HBV remains a challenge in both basic and clinical research. Long-noncoding RNAs (lncRNAs) are generally >200 bp in length and perform different functions in the RNA strand encoding the protein. As an important part of the IFN-inducible genes, interferon-stimulated lncRNAs are involved in the regulation of several HBV infection-related pathways. This review traces the basic elements of such pathways and characterizes the various recent targets of lncRNAs, which not only complement the regulatory mechanisms of pathways related to chronic HBV infection, fibrosis, and cancer promotion but also present with new potential therapeutic targets for controlling HBV infection and the malignant transformation of hepatocytes.

5.
Chempluschem ; 87(5): e202200097, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35510892

RESUMO

Metal oxide materials show promise for application in photoelectrocatalytic conversion due to their inherent advantages involving positive reactive surface, improved light absorption capability, efficient charge separation yield, and fast charge transport channels. The unique electrical and optical properties of metal oxide based photoelectrodes have a great effect on their performance in solar cells, photoelectrocatalysis, and photocatalysis. It has been reported that the presence of defects on grain boundaries, oxygen vacancy, doping strategy, and heterojunction play a vital role in both the efficiency and durability of their photoelectric application. However, the intrinsic mechanisms at the atomic level remained unclear, which require more in-depth understanding in terms of theoretical analysis. In this Review, we emphatically introduce the recent advances and current challenges of metal oxide-based photoelectrodes for photoelectrocatalytic application, beneath the structure-activity relationship of metal oxide catalysts. Then, we give a summary of the state-of-the-art research in the preparation and application for the metal oxide based composite materials. Finally, we discuss key aspects, which should be addressed for design and construction.

6.
mBio ; 13(3): e0067722, 2022 06 28.
Artigo em Inglês | MEDLINE | ID: mdl-35587189

RESUMO

Hepatitis B virus (HBV)-related diseases are among the major diseases that affect millions of people worldwide. These diseases are difficult to eradicate and thus pose a serious global health challenge. There is an urgent need to understand the cross talk mechanism between HBV and the host. Cholesterol-25-hydroxylase (CH25H) and its enzymatic product, 25-hydroxycholesterol (25HC), were previously shown to exhibit effective broad-spectrum antiviral activity. However, the role of CH25H in the regulation of HBV infection and replication remains unclear. The present study reported increased expression of CH25H in HBV-infected patients compared to healthy subjects. Importantly, higher expression of CH25H expression was found to be associated with low HBV replication. Additionally, the present study aimed to identify CH25H mutants, which would lack hydroxylase activity but retain antiviral activity toward HBV infection and replication. Interestingly, it was observed that both CH25H and its mutants interacted with HBx protein and inhibited nuclear translocation of HBx. In particular, CH25H interacted with the C-terminal region of HBx, while transmembrane region 3 of CH25H was found to be critical for CH25H-HBx interaction and inhibition of HBV replication. The study results suggested that 25HC promoted HBV infection but not HBV replication. Thus, the results of the present study suggested the involvement of a dual mechanism in CH25H-mediated regulation of HBV replication. The study clearly demonstrated cross talk between HBV and the host through CH25H-HBx axis. IMPORTANCE The enzymatic product of CH25H, 25-hydroxycholesterol (25HC), has been previously shown to play a critical role in the blockage of the cell-virus fusion in response to viral infection. However, our study indicates a dual role of CH25H in regulating HBV. We find the CH25H-mediated inhibition of HBV replication is independent on its enzyme activity and CH25H binds to HBx and inhibits HBx nucleus translocation. We are interested to find out 25HC promotes HBV infection.


Assuntos
Vírus da Hepatite B , Hepatite B , Esteroide Hidroxilases/metabolismo , Antivirais/farmacologia , Vírus da Hepatite B/genética , Humanos , Proteínas Virais Reguladoras e Acessórias/genética , Replicação Viral
7.
Angew Chem Int Ed Engl ; 60(44): 23735-23742, 2021 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-34410033

RESUMO

Simplified perovskite solar cells (PSCs) were fabricated with the perovskite layer sandwiched and encapsulated between carbon-based electron transport layer (ETL) and counter electrode (CE) by a fully blade-coated process. A self-assembled monolayer of amphiphilic silane (AS) molecules on transparent conducting oxide (TCO) substrate appeals to the fullerene ETL deposition and preserves its integrity against the solvent damage. The AS serves as a "molecular glue" to strengthen the adhesion toughness at the TCO/ETL interface via robust chemical interaction and bonding, facilitating the interfacial charge extraction, increasing PCEs by 77 % and reducing hysteresis. A PCE of 18.64 % was achieved for the fully printed devices, one of the highest reported for carbon-based PSCs. AS-assisted interfacial linkage and carbon-material-assisted self-encapsulation enhance the stability of the PSCs, which did not experience performance degradation when stored at ambient conditions for over 3000 h.

8.
Front Microbiol ; 12: 663534, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34276596

RESUMO

Owing to its broad-spectrum antivirus activities, interferon (IFN) is an important alternative agent for use in the treatment of hepatitis B virus (HBV)-infected patients; however, the mechanism involved in the inhibition of HBV infection and replication by IFN remains unclear. We previously reported that the induction of TRIM5γ is important in the IFN treatment of HBV patients as it promotes the degradation of the HBx protein, while the manner in which TRIM5γ is induced by IFN and how TRIM5γ interacts with HBx remain unestablished until date. Our present findings confirmed the TRIM5γ-HBx-DDB1 interactions in the HBV-infected Primary human hepatocytes (PHH), and we further found that STAT3, and not STAT1, was responsible for the induction of TRIM5γ upon IFN stimulation and that the zinc binding site His123 on the BBOX domain was a decisive site in the interaction between TRIM5γ BBOX and HBx. In addition, based on the BBOX domain, we detected a 7-amino acid peptide with the potential of promoting HBx degradation and inhibiting HBV replication. On the other hand, we noted that the TRIM5γ expression was inhibited by HBV in chronically HBV infected patients. Thus, our study identified the crucial role of STAT3 in the induction of TRIM5γ, as well as proposed a 7-amino acid, small peptide as a potential candidate for the development of therapeutic agents targeting HBx.

9.
Clin Appl Thromb Hemost ; 26: 1076029620953217, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32854513

RESUMO

Deep vein thrombosis (DVT) is prevalent in patients with coronavirus disease 2019 (COVID-19). However, the risk factors and incidence rate of DVT remains elusive. Here, we aimed to assess the incidence rate and risk factors of DVT. All patients diagnosed with COVID-19 and performed venous ultrasound by ultrasound deparment between December 2019 and April 2020 in Wuhan Jin Yin-tan hospital were enrolled. Demographic information and clinical features were retrospectively collected. Notably, a comparison between the DVT and the non-DVT groups was explored. The incidence rate of venous thrombosis was 35.2% (50 patients out of 142). Moreover, the location of thrombus at the proximal extremity veins was 5.6% (n = 8), while at distal extremity veins was 35.2% (n = 50) of the patients. We also noted that patients with DVT exhibited a high level of D-dimer (OR 10.9 (95% CI, 3.3-36.0), P < 0.001), were admitted to the intensive care unit (OR 6.5 (95% CI, 2.1-20.3), P = 0.001), a lower usage of the anticoagulant drugs (OR 3.0 (95% CI, 1.1-7.8), P < 0.001). Finally, this study revealed that a high number of patients with COVID-19 developed DVT. This was observed particularly in critically ill patients with high D-dimer levels who required no anticoagulant medication.


Assuntos
Anticoagulantes/uso terapêutico , Infecções por Coronavirus/epidemiologia , Mortalidade Hospitalar/tendências , Pneumonia Viral/epidemiologia , Trombose Venosa/diagnóstico por imagem , Trombose Venosa/epidemiologia , Adulto , Idoso , COVID-19 , China , Estudos de Coortes , Infecções por Coronavirus/diagnóstico , Infecções por Coronavirus/terapia , Feminino , Hospitalização , Humanos , Incidência , Unidades de Terapia Intensiva/estatística & dados numéricos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Pandemias , Pneumonia Viral/diagnóstico , Pneumonia Viral/terapia , Cobertura de Condição Pré-Existente , Estudos Retrospectivos , Fatores de Risco , Índice de Gravidade de Doença , Ultrassonografia Doppler/métodos , Trombose Venosa/tratamento farmacológico
10.
Mater Sci Eng C Mater Biol Appl ; 49: 34-39, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25686924

RESUMO

In this paper a new electrochemical DNA biosensor was prepared by using graphene (GR) and nickel oxide (NiO) nanocomposite modified carbon ionic liquid electrode (CILE) as the substrate electrode. GR and NiO nanoparticles were electrodeposited on the CILE surface step-by-step to get the nanocomposite. Due to the strong affinity of NiO with phosphate groups of ssDNA, oligonucleotide probe with a terminal 5'-phosphate group could be attached on the surface of NiO/GR/CILE, which could further hybridize with the target ssDNA sequence. Methylene blue (MB) was used as the electrochemical indicator for monitoring the hybridization reaction. Under the optimal conditions the reduction peak current of MB was proportional to the concentration of salmonella enteritidis gene sequence in the range from 1.0×10(-13) to 1.0×10(-6)molL(-1) with a detection limit as 3.12×10(-14)molL(-1). This electrochemical DNA sensor exhibited good discrimination ability to one-base and three-base mismatched ssDNA sequences, and the polymerase chain reaction amplification product of salmonella enteritidis gene sequences were further detected with satisfactory results.


Assuntos
Técnicas Biossensoriais , DNA/análise , Técnicas Eletroquímicas/métodos , Grafite/química , Nanopartículas Metálicas , Níquel/química , Salmonella enteritidis/genética , Genes Bacterianos , Microscopia Eletrônica de Varredura
11.
Biosens Bioelectron ; 64: 131-7, 2015 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-25212067

RESUMO

In this paper a graphene (GR) and copper sulfide (CuS) nanocomposite was synthesized by hydrothermal method and used for the electrode modification with a N-butylpyridinium hexafluorophosphate based carbon ionic liquid electrode (CILE) as the substrate electrode. Hemoglobin (Hb) was immobilized on the modified electrode to get a biocompatible sensing platform. UV-vis absorption spectroscopic results confirmed that Hb retained its native secondary structure in the composite. Direct electron transfer of Hb incorporated into the nanocomposite was investigated with a pair of well-defined redox waves appeared on cyclic voltammogram, indicating the realization of direct electrochemistry of Hb on the modified electrode. The results can be ascribed to the presence of GR-CuS nanocomposite on the electrode surface that facilitates the electron transfer rate between the electroactive center of Hb and the electrode. The Hb modified electrode showed excellent electrocatalytic activity to the reduction of trichloroacetic acid in the concentration range from 3.0 to 64.0 mmol L(-1) with the detection limit of 0.20 mmol L(-1) (3σ). The fabricated biosensor displayed the advantages such as high sensitivity, good reproducibility and long-term stability.


Assuntos
Condutometria/instrumentação , Cobre/química , Eletrodos , Grafite/química , Hemoglobinas/análise , Hemoglobinas/química , Nanocompostos/química , Catálise , Materiais Revestidos Biocompatíveis/síntese química , Desenho de Equipamento , Análise de Falha de Equipamento , Líquidos Iônicos/química , Nanocompostos/ultraestrutura , Tamanho da Partícula , Sulfetos/química
12.
J Phys Chem B ; 117(41): 12525-34, 2013 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-24053572

RESUMO

The diffusion coefficients of n-alkanes (from CH4 to C14H30) in near critical and supercritical carbon dioxide at infinite dilution have been studied by molecular dynamics simulation. The simulation results agree well with experiment, which suggests that the simulation method is a powerful tool to obtain diffusion coefficients of solutes in fluids at high pressures. The local structures of such fluids are further investigated by calculating radial distribution functions and coordination numbers. Meanwhile, the dihedral, end-to-end distance and radius of gyration, which are calculated to characterize the flexibility of n-alkanes, are used to reasonably explain the abnormal trends on radial distribution functions and coordination numbers. Moreover, it is found that the flexibility effects on diffusion in pure n-alkanes and infinitely dilute n-alkane/CO2 system are different. The differences in MD simulation results of molecular diffusion in such systems could be qualitatively explained by the flexibility.

13.
Mater Sci Eng C Mater Biol Appl ; 33(4): 1907-13, 2013 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-23498212

RESUMO

In this paper a platinum (Pt) nanoparticle decorated graphene (GR) nanosheet was synthesized and used for the investigation on direct electrochemistry of myoglobin (Mb). By integrating GR-Pt nanocomposite with Mb on the surface of carbon ionic liquid electrode (CILE), a new electrochemical biosensor was fabricated. UV-Vis absorption and FT-IR spectra indicated that Mb remained its native structure in the nanocomposite film. Electrochemical behaviors of Nafion/Mb-GR-Pt/CILE were investigated with a pair of well-defined redox peak appeared, which indicated that direct electron transfer of Mb was realized on the underlying electrode with the usage of the GR-Pt nanocomposite. The fabricated electrode showed good electrocatalytic activity to the reduction of trichloroacetic acid in the linear range from 0.9 to 9.0 mmol/L with the detection limit as 0.32 mmol/L (3σ), which showed potential application for fabricating novel electrochemical biosensors and bioelectronic devices.


Assuntos
Eletroquímica/métodos , Grafite/química , Mioglobina/química , Nanocompostos/química , Platina/química , Animais , Catálise , Espectroscopia Dielétrica , Eletrodos , Polímeros de Fluorcarboneto/química , Cavalos , Concentração de Íons de Hidrogênio , Líquidos Iônicos/química , Nanocompostos/ultraestrutura , Reprodutibilidade dos Testes , Espectrofotometria Ultravioleta , Espectroscopia de Infravermelho com Transformada de Fourier
14.
Biosens Bioelectron ; 44: 146-51, 2013 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-23416316

RESUMO

In this paper an ionic liquid 1-hexylpyridinium hexafluorophosphate based carbon ionic liquid electrode (CILE) was fabricated and used as the basal electrode, which was further modified by graphene (GR) and ZrO2 nanoparticle with chitosan (CTS) film to immobilize the nanocomposite. The modified electrode was denoted as CTS-GR-ZrO2/CILE and further used for the simultaneous detection of adenosine and guanosine. Electrochemical performances of the modified electrode were greatly enhanced due to the presence of GR-ZrO2 nanocomposite, and the direct electro-oxidation behaviors of adenosine and guanosine were carefully investigated. Both adenosine and guanosine exhibited an increase of the oxidation peak currents with the negative shift of the oxidation peak potentials on the modified electrode, which indicated the electrocatalytic activity of GR-ZrO2 nanocomposite on the electrode surface. Electrochemical parameters of adenosine and guanosine on CTS-GR-ZrO2/CILE were calculated respectively, and a new electroanalytical method for the simultaneous determination of adenosine and guanosine was further established with the peak-to-peak separation (ΔEp) as 0.225V. The proposed method was successfully applied to detect adenosine and guanosine in human urine samples with satisfactory results.


Assuntos
Adenosina/urina , Técnicas Eletroquímicas/instrumentação , Grafite/química , Guanosina/urina , Líquidos Iônicos/química , Nanocompostos/química , Zircônio/química , Carbono/química , Eletrodos , Humanos , Nanocompostos/ultraestrutura , Sensibilidade e Especificidade
15.
Sci Rep ; 3: 1352, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23443301

RESUMO

Hierarchical anatase TiO(2) nano-architecture arrays consisting of long TiO(2) nanowire trunk and numerous short TiO(2) nanorod branches on transparent conductive fluorine-doped tin oxide glass are successfully synthesized for the first time through a facile one-step hydrothermal route without any surfactant and template. Dye-sensitized solar cells based on the hierarchical anatase TiO(2) nano-architecture array photoelectrode of 18 µm in length shows a power conversion efficiency of 7.34% because of its higher specific surface area for adsorbing more dye molecules and superior light scattering capacity for boosting the light-harvesting efficiency. The present photovoltaic performance is the highest value for the reported TiO(2) nanowires array photoelectrode.

16.
Phys Chem Chem Phys ; 14(38): 13175-9, 2012 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-22914771

RESUMO

A novel hierarchical TiO(2) flower consisting of anatase TiO(2) nanotubes on a Ti foil substrate has been prepared via a mild hydrothermal reaction of TiO(2) nanoparticles/Ti foil. The photovoltaic performance of DSSC based on hierarchical TiO(2) flowers/Ti (7.2%) is much higher than that of TiO(2) nanoparticle/Ti (6.63%) because of its superior light scattering ability and fast electron transport. Moreover, full flexible DSSC based on the novel hierarchical TiO(2) flowers/Ti foil photoelectrode and electrodeposited poly(3,4-ethylenedioxythiophene) (PEDOT) on indium tin oxide-coated poly(ethylene terephthalate) (ITO-PET) counter electrode shows a significant power conversion efficiency of 6.26%, accompanying a short-circuit current density of 11.96 mA cm(-2), an open-circuit voltage of 761 mV and a fill factor of 0.69.

17.
Chem Asian J ; 7(8): 1795-802, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22570255

RESUMO

Low-cost transparent counter electrodes (CEs) for efficient dye-sensitized solar cells (DSSCs) are prepared by using nanohybrids of carbon nanotube (CNT)-supported platinum nanoparticles as highly active catalysts. The nanohybrids, synthesized by an ionic-liquid-assisted sonochemical method, are directly deposited on either rigid glass or flexible plastic substrates by a facile electrospray method for operation as CEs. Their electrochemical performances are examined by cyclic voltammetry, current density-voltage characteristics, and electrochemical impedance spectroscopy (EIS) measurements. The CNT/Pt hybrid films exhibit high electrocatalytic activity for I(-)/I(3)(-) with a weak dependence on film thickness. A transparent CNT/Pt hybrid CE film about 100 nm thick with a transparency of about 70% (at 550 nm) can result in a high power conversion efficiency (η) of over 8.5%, which is comparable to that of pyrolysis platinum-based DSSCs, but lower cost. Furthermore, DSSC based on flexible CNT/Pt hybrid CE using indium-doped tin oxide-coated polyethylene terephthalate as the substrate also exhibits η=8.43% with J(sc)=16.85 mA cm(-2), V(oc)=780 mV, and FF=0.64, and this shows great potential in developing highly efficient flexible DSSCs.


Assuntos
Corantes/química , Nanopartículas Metálicas/química , Nanotubos de Carbono/química , Platina/química , Energia Solar , Catálise , Espectroscopia Dielétrica , Fontes de Energia Elétrica , Eletrodos , Índio/química , Oxirredução , Polietilenotereftalatos/química
18.
Chemistry ; 17(4): 1352-7, 2011 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-21243703

RESUMO

One-dimensional and quasi-one-dimensional semiconductor nanostructures are desirable for dye-sensitized solar cells (DSSCs), since they can provide direct pathways for the rapid collection of photogenerated electrons, which could improve the photovoltaic performance of the device. Quasi-1D single-crystalline anatase TiO(2) nanostructures have been successfully prepared on transparent, conductive fluorine-doped tin oxide (FTO) glass with a growth direction of [101] through a facile hydrothermal approach. The influences of the initial titanium n-butoxide (TBT) concentration, hydrothermal reaction temperature, and time on the length of quasi-1D anatase TiO(2) nanostructures and on the photovoltaic performance of DSSCs have been investigated in detail. A power conversion efficiency of 5.81% has been obtained based on the prepared TiO(2) nanostructure photoelectrode 6.7 µm thick and commercial N719 dye, with a short-circuit current density of 13.3 mA cm(-2) , an open-circuit voltage of 810 mV, and a fill factor of 0.54.

19.
Chemistry ; 16(29): 8757-61, 2010 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-20572173

RESUMO

Hierarchical ZnO hollow spheres (400-500 nm in diameter) consisting of ZnO nanoparticles with a diameter of approximately 15 nm have been successfully prepared by a facile and rapid sonochemical process. The formation of hierarchical ZnO hollow spheres is attributed to the oriented attachment and subsequent Ostwald ripening process according to time-dependent experiments. The as-prepared ZnO hollow spheres are used as a photoanode in dye-sensitized solar cells and exhibit a highly efficient power conversion efficiency of 4.33%, with a short-circuit current density of 9.56 mA cm(-2), an open-circuit voltage of 730 mV, and a fill factor of 0.62 under AM 1.5 G one sun (100 mW cm(-2)) illumination. Moreover, the photovoltaic performance (4.33%) using the hierarchical ZnO hollow spheres is 38.8% better than that of a ZnO nanoparticle photoelectrode (3.12%), which is mainly attributed to the efficient light scattering for the former.


Assuntos
Fontes de Energia Elétrica , Nanoestruturas/química , Energia Solar , Óxido de Zinco/química , Óxido de Zinco/síntese química , Corantes/química , Microscopia Eletrônica de Varredura , Fotoquímica
20.
Inorg Chem ; 49(4): 1679-86, 2010 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-20063879

RESUMO

Hierarchical SnO(2) microspheres consisting of nanosheets on the fluorine-doped tin oxide (FTO) glass substrates are successfully prepared via a facile hydrothermal synthesis process. The as-prepared novel microsphere films were characterized in detail by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), UV-vis diffuse reflectance spectroscopy. Moreover, SnO(2) nanoparticles with 30-80 nm in size covered on the surface of nanosheets/microspheres were also obtained by optimizing the hydrothermal reaction temperature, time, or volume ratio of acetylacetone/H(2)O. The detailed investigations disclose the experimental parameters, such as acetylacetone, NH(4)F, and seed layer play important roles in the morphology of hierarchical SnO(2) microspheres on the FTO glass. The formation process of SnO(2) microspheres is also proposed based on the observations of time dependent samples.


Assuntos
Fluoretos/química , Microscopia Eletrônica de Transmissão/métodos , Microesferas , Compostos de Estanho/química , Estanho/química , Vidro/química , Óxidos/química , Fotoquímica , Propriedades de Superfície , Óxido de Zinco/química
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