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1.
Nano Lett ; 24(11): 3361-3368, 2024 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-38446607

RESUMO

For the first time, a series of MXene (Ti3C2Tx)/Bi2WO6 Schottky junction piezocatalysts were constructed, and the piezocatalytic hydrogen evolution activity was explored. Optimal Ti3C2Tx/Bi2WO6 exhibits the highest piezocatalytic hydrogen evolution rate of 764.4 µmol g-1 h-1, which is nearly 8 times higher than that of pure Ti3C2Tx and twice as high as that of Bi2WO6. This value also surpasses that of most recently reported typical piezocatalysts. Moreover, related experimental results and density functional theory calculations reveal that Ti3C2Tx/Bi2WO6 can provide unique channels for efficient electron transfer, enhance piezoelectric properties, optimize the adsorption Gibbs free energy of water, reduce activation energy for hydrogen atoms, endow robust separation capacity of charge carrier, and restrict the electron-hole recombination rate, thus significantly promoting the efficiency of hydrogen evolution reaction. Ultimately, we have unraveled an innovative piezocatalytic mechanism. This work broadens the scope of MXene materials in a sustainable energy piezocatalysis application.

2.
Small ; 20(23): e2307771, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38155151

RESUMO

Constructing quantum dot-scale metal sulfides with defects and strongly coupled with carbon is significant for advanced sodium-ion batteries (SIBs). Herein, Se substituted V3S4 quantum dots with anionic defects confined in nitrogen-doped carbon matrix (V3S4-xSex/NC) are fabricated. Introducing element Se into V3S4 crystal expands the interlayer distance of V3S4, and triggers anionic defects, which can facilitate Na+ diffusions and act as active sites for Na+ storage. Meanwhile, the quantum dots tightly encapsulated by conductive carbon framework improve the stability and conductivity of the electrode. Theoretical calculations also unveil that the presence of Se enhances the conductivity and Na+ adsorption ability of V3S4-xSex. These properties contribute to the V3S4-xSex/NC with high specific capacity of 447 mAh g-1 at 0.2 A g-1, and prominent rate and cyclic performance with 504 mAh g-1 after 1000 cycles at 10 A g-1. The sodium-ion hybrid capacitors (SIHCs) with V3S4-xSex/NC anode and activated carbon cathode can achieve high energy/power density (maximum 144 Wh kg-1/5960 W kg-1), capacity retention ratio of 71% after 4000 cycles at 2 A g-1. This work not only synthesizes V3S4-xSex/NC, but also provides a promising opportunity for designing quantum dots and utilizing defects to improve the electrochemical properties.

3.
BMC Cancer ; 24(1): 239, 2024 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-38383334

RESUMO

PURPOSE: The purpose of this study was to explore the expression and potential mechanism of hsa_circ_0005397 in hepatocellular carcinoma progression. METHODS: Quantitative reverse transcription-polymerase chain reaction(qRT-PCR) was used to measure the expression level of hsa_circ_0005397 and EIF4A3 from paired HCC tissues and cell lines. Western Blot (WB) and immunohistochemistry (IHC) were used to verify the protein level of EIF4A3. The specificity of primers was confirmed by agarose gel electrophoresis. Receiver Operating Characteristic (ROC) Curve was drawn to analyze diagnostic value. Actinomycin D and nuclear and cytoplasmic extraction assays were utilized to evaluate the characteristics of hsa_circ_0005397. Cell Counting kit-8 (CCK-8) and colony formation assays were performed to detect cell proliferation. Flow cytometry analysis was used to detect the cell cycle. Transwell assay was performed to determine migration and invasion ability. RNA-binding proteins (RBPs) of hsa_circ_0005397 in HCC were explored using bioinformatics websites. The relationship between hsa_circ_0005397 and Eukaryotic Translation Initiation Factor 4A3 (EIF4A3) was verified by RNA Binding Protein Immunoprecipitation (RIP) assays, correlation and rescue experiments. RESULTS: In this study, hsa_circ_0005397 was found to be significantly upregulated in HCC, and the good diagnostic sensitivity and specificity shown a potential diagnostic capability. Upregulated expression of hsa_circ_0005397 was significantly related to tumor size and stage. Hsa_circ_0005397 was circular structure which more stable than liner mRNA, and mostly distributed in the cytoplasm. Upregulation of hsa_circ_0005397 generally resulted in stronger proliferative ability, clonality, and metastatic potency of HCC cells; its downregulation yielded the opposite results. EIF4A3 is an RNA-binding protein of hsa_circ_0005397, which overexpressed in paired HCC tissues and cell lines. In addition, expression of hsa_circ_0005397 decreased equally when EIF4A3 was depleted. RIP assays and correlation assay estimated that EIF4A3 could interacted with hsa_circ_0005397. Knockdown of EIF4A3 could reverse hsa_circ_0005397 function in HCC progression. CONCLUSIONS: Hsa_circ_0005397 promotes progression of hepatocellular carcinoma through EIF4A3. These research findings may provide novel clinical value for hepatocellular carcinoma.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , MicroRNAs , Humanos , Carcinoma Hepatocelular/patologia , Neoplasias Hepáticas/patologia , RNA Circular/genética , RNA Circular/metabolismo , Regulação para Baixo , Linhagem Celular Tumoral , Proliferação de Células/genética , Regulação Neoplásica da Expressão Gênica , MicroRNAs/genética , Fator de Iniciação 4A em Eucariotos/genética , Fator de Iniciação 4A em Eucariotos/metabolismo , RNA Helicases DEAD-box/genética
4.
Inorg Chem ; 63(5): 2803-2813, 2024 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-38243893

RESUMO

Developing low-cost electrocatalysts with excellent activity and durability in urea-assisted water splitting is urgently needed in order to achieve sustainable hydrogen production. Herein, we in situ synthesized a robust coupled heterostructured electrocatalyst (CoP/MoO2) on a nickel foam (NF) substrate and explored its electrocatalytic performances in the hydrogen evolution reaction (HER), oxygen evolution reaction (OER), and urea oxidation reaction (UOR). The overpotential of CoP/MoO2/NF is found to be only 11 mV at 10 mA cm-2 during the HER process, which is significantly lower than that of commercial Pt/C. Meanwhile, the UOR catalytic performance of CoP/MoO2/NF indicates fast reaction kinetics, along with a considerable low driving potential (1.26 V) compared to that of the OER (1.51 V). In situ and ex situ techniques demonstrate that these excellent electrocatalytic properties are mainly ascribed to the effective synergistic coupled effect and strong electronic interactions between single-component CoP and MoO2, which can tune electronic states of Co and Mo, expose more active sites, enhance intrinsic catalytic activity, and accelerate charge transfer. Moreover, when used in electrochemical overall water splitting and urea-assisted water electrolysis, CoP/MoO2/NF can reach a current density of 10 mA cm-2 at only 1.46 and 1.32 V. This outperforms Pt/C||RuO2 and numerous nonprecious metal electrocatalysts and maintains a stable long-term electrolytic operation for 84 h. This work provides a promising pathway for the development of efficient catalysts during urea-assisted water electrolysis for hydrogen production.

5.
Inorg Chem ; 63(7): 3467-3476, 2024 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-38306402

RESUMO

The energy gap and conduction band position of catalysts play crucial roles in solar-to-hydrogen (STH) transformation technology. Unfortunately, although an increase in the conduction band position can effectively promote the photoreduction capacity of the photocatalyst, it will inevitably widen the band gap, thus reducing the light-absorption scale. It seems that there is a contradiction between the reduction of band gap and the improvement of conduction band position, which is that "You can't have your cake and eat it too." Herein, an ultrasimple molecular adsorption strategy was engineered by adsorbing hydrazine hydrate on the surface of TiO2. The theoretical and experimental results indicated that the strong electron-donating effect of amino groups in hydrazine hydrate can promote the redistribution of photogenerated electrons and form surface electron networks on the surface of TiO2 photocatalysts, which can bend the conduction band upward and significantly improve its photoreduction ability. Besides, the adsorption of -NH2 can narrow the band gap width of TiO2 and promote the separation efficiency of photogenerated carriers. More interestingly, it can also effectively enhance the adsorption of H2O and H+, thus greatly elevating the STH efficiency. The STH rate of the as-prepared T-N-3 can be increased by ≈530%. This work sheds light on a new approach for resolving the contradiction between photoreduction and light absorption capabilities to effectively enhance photocatalytic performance.

6.
Molecules ; 29(6)2024 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-38543005

RESUMO

The development of electrode materials with excellent performance serves as the key for researchers to enhance the energy density of supercapacitors. Cobalt molybdate (CoMoO4) nanomaterials have been regarded as one of the most prospective electrode materials for supercapacitors due to their high theoretical capacitance and excellent electrical conductivity. In this paper, three kinds of CoMoO4 nanorods were prepared directly via simple and environmentally friendly solid-phase chemical reactions with solid inorganic salts as raw materials. According to X-ray powder diffraction (XRD) and scanning electron microscopy (SEM) test results, different reagents had certain effects on the size and morphology of CoMoO4, and these affected its electrochemical performance. In particular, the samples prepared with Co(NO3)2·6H2O as raw material took on a more uniform micromorphology, with a better crystallinity. Simultaneously, electrochemical test results showed that the samples synthesized with Co(NO3)2·6H2O presented relatively good electrical conductivity and a large specific capacitance (177 F g-1). This may be due to the nitrates reacting more slowly during the reaction and the crystals having difficulty aggregating during growth. Therefore, the structure of the prepared CoMoO4 nanomaterial was more uniform, and it was resistant to collapse during the charging and discharging process; thus, the capacitor presents the best performance.

7.
Small ; 19(36): e2301294, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37127885

RESUMO

Nickel-iron based hydroxides have been proven to be excellent oxygen evolution reaction (OER) electrocatalysts, whereas they are inactive toward hydrogen evolution reaction (HER), which severely limits their large-scale applications in electrochemical water splitting. Herein, a heterostructure consisted of NiFeV hydroxide and iron oxide supported on iron foam (NiFeV@FeOx /IF) has been designed as a highly efficient bifunctional (OER and HER) electrocatalyst. The V doping and intimate contact between NiFeV hydroxide and FeOx not only improve the entire electrical conductivity of the catalyst but also afford more high-valence Ni which serves as active sites for OER. Meanwhile, the introduction of V and FeOx reduces the electron density on lattice oxygen, which greatly facilitates desorption of Hads . All of these endow the NiFeV@FeOx /IF with exceptionally low overpotentials of 218 and 105 mV to achieve a current density of 100 mA cm-2 for OER and HER, respectively. More impressively, the electrolyzer requires an ultra-low cell voltage of 1.57 V to achieve 100 mA cm-2 and displays superior electrochemical stability for 180 h, which outperforms commercial RuO2 ||Pt/C and most of the representative catalysts reported to date. This work provides a unique route for developing high-efficiency electrocatalyst for overall water splitting.

8.
Small ; 19(16): e2207214, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36670333

RESUMO

The exploitation of electrode materials with ability to balance capacity and kinetics between cathode and anode is a challenge for sodium-ion hybrid capacitors (SIHCs). Mn-based anode materials are limited by poor electrical conductivity, sluggish reaction kinetics, large volume variation, weak cycling stability, and inferior reversible capacity. Herein, MnS nanocubes encapsulated in S-doped porous carbon matrix (MSC) with strong sulfur-bridged bond interactions (CSMn) are successfully synthesized by solvent-free tactics. The CSMn bonds generated between MnS and carbon significantly inhibit the aggregation of nanostructural MnS cubes, restrict the volume expansion, and stabilize the nanostructure, which improves the Na+ storage reversibility and stability. Moreover, S-doped porous carbon enhances the electrical conductivity and electrons/ions diffusion rate, which boosts a fast kinetic reaction. As expected, MSC anode presents an outstanding reversible capacity of 600 mAh g-1 at 0.2 A g-1 and a long-term stable capacity of 357 mAh g-1 for 1000 cycles at a high current density of 10 A g-1 in sodium-ion batteries (SIBs). The as-assembled SIHCs deliver a high energy density of 109 W h kg-1 and a high power output of 98 W kg-1 , with 88% capacity retention at 2 A g-1 after 2000 cycles and practical applications (55 LEDs can be lighted for 10 min).

9.
Inorg Chem ; 62(8): 3532-3540, 2023 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-36791254

RESUMO

Electrocatalytic water splitting is still circuitous and controversial because of the lack of highly active electrocatalysts to decrease the overpotential. Herein, we report a feasible method for constructing heterojunctions of MnO2-Co3O4 nanosheets on Co@NCNT support surfaces (MnO2-Co3O4/Co@NCNT) by spontaneous redox reactions. Experimental results indicate that Co embedded in Co@NCNT can be used as the carbon support and anchoring sites for heterojunctions, thus exposing a large number of active sites, adjusting the surface electronic structure, changing the OER rate-determining step of the catalyst, and reducing the reaction energy barrier. Besides, the in situ formation of MnO2-Co3O4 nanosheets on Co@NCNT inhibits the loss and aggregation of the catalyst, leading to robust structural stability. Therefore, the synergistic effects of these factors provide multi-functional active sites to enhance the intrinsic activity and achieve maximum catalytic performances. To deliver a current density of 10 mA cm-2, the catalyst of MnO2-Co3O4/Co@NCNT achieves an overpotential (η) of 303 mV in 1.0 M KOH media for OER. This simple redox strategy can be easily extended to prepare other ultrathin transition-metal oxide heterojunctions, which could be applied not only for water splitting but also for other energy conversion and storage technologies.

10.
Inorg Chem ; 62(37): 15249-15257, 2023 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-37676295

RESUMO

Constructing heterojunctions with strong interfacial interactions can accelerate the transfer and separation of photogenerated charge carriers. However, finding a simple strategy to construct tightly connected heterojunctions remains a major challenge. In this work, AgBr/BiOBr S-scheme heterojunctions were designed via a straightforward co-anionic strategy without using a solvent. The experimental results indicate that the AgBr/BiOBr heterojunction with a close contact interface can extend the use of visible light, accelerate the separation, and induce the transfer of photoelectrons and holes while maintaining an excellent redox capacity. Undoubtedly, the photocatalytic reduction rate of carbon dioxide to carbon monoxide by 1.0 AgBr/BiOBr is 87.73 µmol·g-1·h-1 (quantum efficiency is 0.57%), which is 12.15 times and 4.45 times higher than that of pure AgBr and BiOBr, respectively. The present work provides insights into a simple strategy for the preparation of strongly interacting interfacial heterojunctions for photocatalytic CO2 reduction.

11.
Inorg Chem ; 62(16): 6428-6438, 2023 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-37032488

RESUMO

Developing high-efficiency, low-cost, and earth-abundant electrocatalysts toward the oxygen evolution reaction (OER) and the hydrogen evolution reaction (HER) is highly desirable for boosting the energy efficiency of water splitting. Herein, we adopted an interfacial engineering strategy to enhance the overall water splitting (OWS) activity via constructing a bifunctional OER/HER electrocatalyst combining MoS2-Ni3S2 with NiFe layered double hydroxide (NiFe-LDH) on a nickel foam substrate. The NiFe-LDH/MoS2-Ni3S2/NF electrocatalyst delivers superior OER/HER activity and stability, such as low overpotentials (220 and 79 mV for OER and HER at current densities of 50 and 10 mA cm-2, respectively) and a low Tafel slope. This excellent electrocatalytic performance mainly benefits from the electronic structure modulation and synergistic effects between NiFe-LDH and MoS2-Ni3S2, which provides a high electrochemical activity area, more active sites, and strong electron interaction. Furthermore, the assembly of NiFe-LDH/MoS2-Ni3S2/NF into a two-electrode system only requires an ultra-low cell voltage of 1.50 V at a current density of 10 mA cm-2 and exhibits outstanding stability with a decay of current density of only 2.11% @50 mA cm-2 after 50 h, which is far superior to numerous other reported transition metal NiFe-LDH and MoS2-Ni3S2-based as well as RuO2||Pt-C electrocatalysts. This research highlights the rational design of heterostructures to efficiently advance electrocatalysis for water splitting applications.

12.
J Appl Microbiol ; 134(10)2023 Oct 04.
Artigo em Inglês | MEDLINE | ID: mdl-37833234

RESUMO

AIMS: Disabling bacterial virulence with small molecules has been proposed as a potential strategy to prevent bacterial pathogenicity. The von Willebrand factor-binding protein of Staphylococcus aureus was identified previously as a key virulence determinant. Our objective was to discover a von Willebrand-factor binding protein (vWbp) inhibitor distinct from the antibiotics used to prevent infections resulting from S. aureus. METHODS AND RESULTS: Using coagulation assays, we found that the sesquiterpene trilactone bilobalide blocks coagulation mediated by vWbp, but has no impact on the growth of S. aureus at a concentration of 128 µg ml-1. Moreover, a mouse model of pneumonia caused by S. aureus indicated that bilobalide could attenuate S. aureus virulence in vivo. This effect is achieved not by interfering with the expression of vWbp but by binding to vWbp, as demonstrated by western blotting, thermal shift assays, and fluorescence quenching assays. Using molecular dynamic simulations and point mutagenesis analysis, we identified that the Q17A and R453A residues are key residues for the binding of bilobalide to vWbp. CONCLUSIONS: Overall, we tested the ability of bilobalide to inhibit S. aureus infections by targeting vWbp and explored the potential mechanism of this activity.


Assuntos
Bilobalídeos , Pneumonia , Infecções Estafilocócicas , Camundongos , Animais , Proteínas de Transporte/metabolismo , Fator de von Willebrand/genética , Fator de von Willebrand/metabolismo , Staphylococcus aureus/metabolismo , Infecções Estafilocócicas/tratamento farmacológico
13.
Molecules ; 28(14)2023 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-37513170

RESUMO

Direct formic acid fuel cells (DFAFCs) are one of the most promising power sources due to its high conversion efficiency; relatively low carbon emissions, toxicity, and flammability; convenience; and low-cost storage and transportation. However, the key challenge to large-scale commercial applications is its poor power performance and the catalyst's high preparation cost. In this study, a new sandwich-structured Pd/polypyrrole-graphene/Pd (Pd/PPy-Gns/Pd)-modified glassy carbon electrode (GCE) was prepared using a simple constant potential (CP) electrodeposition technique. On the basis of the unique synthetic procedure and structural advantages, the Pd/PPy-Gns/Pd shows a fast charge/mass transport rate, high electrocatalytic activity, and great stability for formic acid electro-oxidation (FAO). The mass activity of Pd/PPy-Gns/Pd electrode reaches 917 mA·mg-1Pd. The excellent catalytic activity is mainly due to the uniform embedding of Pd nanoparticles on the polypyrrole-graphene (PPy-Gns) support, which exposes more active sites, and prevents the shedding and inactivation of Pd nanoparticles. At the same time, the introduction of graphene (Gns) in the PPy further improved the conductivity of the catalyst and accelerated the transfer of electrons.

14.
Molecules ; 28(9)2023 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-37175089

RESUMO

BiOIO3 exhibits excellent oxidation capacity in the photocatalytic degradation of contaminants thanks to its unique polarized electric and internal electrostatic field. However, the synthetic method of BiOIO3 nanomaterials is mainly focused on hydrothermal technology, owing to its high energy consumption and time-consuming nature. In this work, a BiOIO3 nanosheet was prepared by a simple solid-state chemical reaction, which was identified by XRD, EDS, XPS, and HRTEM. Benefiting from the strong oxidation ability of the valence band maximum, the distinctive layer structure, and the promoted generation of ·O2-, the BiOIO3 nanosheet exhibits excellent photo-degradation activity for methyl orange (MO) and its apparent rate constant is 0.2179 min-1, which is about 3.02, 8.60, and 10.26 times higher than that of P25, BiOCl, and Bi2O2CO3, respectively. Interestingly, the BiOIO3 nanosheet also has good photocatalytic degradation performance for phenolic compounds; in particular, the degradation rate of BPA can reach 96.5% after 16 min, mainly due to hydroxylation reaction.

15.
Inorg Chem ; 61(21): 8217-8225, 2022 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-35584061

RESUMO

Defects play a vital role in improving photocatalytic performance. However, the specific influence mechanism of sulfur defects (DSS) on sulfide photocatalytic performance and stability is still unclear. In this work, an ingenious solvent-free self-overflow strategy is designed to introduce DSS into ZnS nanoparticles and explore the specific promotion mechanism of photocatalytic performance and photostability. The results indicate that the introduced DSS in ZnS nanoparticles can simultaneously boost the photocatalytic hydrogen production (PHE) performance and photostability of ZnS: the PHE rate of the defective ZnS can increase up to 21350.23 µmol·h-1·g-1, which is roughly 4.7 times higher than that of pristine ZnS. Both experiments and theoretical calculationsshow that the enhanced photocatalytic performance could be attributed to the change of energy band position after introducing DSS. Specifically, the introduction of DSS can raise the conduction band (CB) position of ZnS to enhance the reducing ability of photogenerated electrons. Besides, the valence band (VB) position can also be raised to boost the light absorption ability of ZnS and restrain the photocorrosion by weakening the oxidation capacity of the photogenerated holes. The ingenious strategy and interesting mechanism in this job provide a simple artful tactic to fabricate other defective sulfide photocatalysts and open up a particular path to promote the photostability of the photocatalysts.

16.
Int J Mol Sci ; 23(12)2022 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-35743296

RESUMO

Carbon monoxide (CO) oxidation performance heavily depends on the surface-active species and the oxygen vacancies of nanocomposites. Herein, the CuOx/Cu1.5Mn1.5O4 were fabricated via solid-state strategy. It is manifested that the construction of CuOx/Cu1.5Mn1.5O4 nanocomposite can produce abundant surface CuOx species and a number of oxygen vacancies, resulting in substantially enhanced CO oxidation activity. The CO is completely converted to carbon dioxide (CO2) at 75 °C when CuOx/Cu1.5Mn1.5O4 nanocomposites were involved, which is higher than individual CuOx, MnOx, and Cu1.5Mn1.5O4. Density function theory (DFT) calculations suggest that CO and O2 are adsorbed on CuOx/Cu1.5Mn1.5O4 surface with relatively optimal adsorption energy, which is more beneficial for CO oxidation activity. This work presents an effective way to prepare heterogeneous metal oxides with promising application in catalysis.


Assuntos
Nanocompostos , Oxigênio , Catálise , Cobre
17.
Small ; 17(52): e2104656, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34741432

RESUMO

Simultaneous boosting electrochemical methanol oxidation reaction (MOR) for direct methanol fuel cells and production of hydrogen is meaningful but challenging. Herein, a sea urchin-shaped cobalt-embedded N-doped carbon nanotubes (Co@NCNT) encapsulated CoPt3 @Co2 P heterojunction (CoPt3 @Co2 P/Co@NCNT) is fabricated. Theoretical calculations confirm that electrons at the interfaces transfer from CoPt3 to Co2 P, where electron hole region on CoPt3 is beneficial to improving the MOR activity, whereas accumulation region on Co2 P favors to the optimization of H2 O and H* absorption energies for hydrogen evolution reaction (HER). Benefitting from its interfacial electronic reconfiguration, the CoPt3 @Co2 P/Co@NCNT heterojunction exhibits excellent electrocatalytic performances for MOR and HER, in which the mass activity (2981 mA mgPt -1 ) for MOR is 14.2 times than that of Pt/C (20%), and the smallest overpotentials only requires 19 mV to deliver a current density of 10 mA cm-2 for HER. Moreover, the electrolyzer employing CoPt3 @Co2 P/Co@NCNT for anodic MOR and cathodic H2 production only requires a low voltage of 1.43 V at 10 mA cm-2 with impressive long-life cycling stability, which is obviously better than that of commercial Pt/C//RuO2 . This study offers a novel strategy for other organics oxidation reaction coupled with HER catalyzed production of hydrogen.

18.
Inorg Chem ; 60(8): 5812-5820, 2021 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-33783206

RESUMO

α-MnO2 nanorods and flower-like γ-MnO2 microspheres were synthesized by facile and mild methods to illustrate the effect of crystal structures and surface features on catalytic performance with the help of carbon monoxide (CO) oxidation. It is revealed that the flower-like γ-MnO2 microspheres possess better catalytic oxidation performance (CO complete conversion temperature at 120 °C and long-time stability for 50 h) than α-MnO2 nanorods, which can be attributed to the obvious differences in the chemical bonds and linking modes of [MnO6] octahedra due to the different crystal structures. γ-MnO2 possesses lower Mn-O bond strength that enables γ-MnO2 to present a large amount of surface lattice oxygen and superior oxygen mobility. The disordered random intergrowth tunnel structure can adsorb effectively CO molecules, resulting in excellent catalytic performance for CO catalytic oxidation. In addition, the MnO2 catalyst probably occurred via a Mars-van Krevelen mechanism for CO oxidation. This work provides an insight into the effect of crystal structures and surface property of manganese oxide on catalytic oxidation performance, which presents help for the future design of promising catalysts with excellent catalytic performance.

19.
Sensors (Basel) ; 20(1)2019 Dec 25.
Artigo em Inglês | MEDLINE | ID: mdl-31881692

RESUMO

Inspired by the enhanced gas-sensing performance by the one-dimensional hierarchical structure, one-dimensional hierarchical polyaniline/multi-walled carbon nanotubes (PANI/CNT) fibers were prepared. Interestingly, the simple heating changed the sensing characteristics of PANI from p-type to n-type and n-type PANI and p-type CNTs form p-n hetero junctions at the core-shell interface of hierarchical PANI/CNT composites. The p-type PANI/CNT (p-PANI/CNT) and n-type PANI/CNT (n-PANI/CNT) performed the higher sensitivity to NO2 and NH3, respectively. The response times of p-PANI/CNT and n-PANI/CNT to 50 ppm of NO2 and NH3 are only 5.2 and 1.8 s, respectively, showing the real-time response. The estimated limit of detection for NO2 and NH3 is as low as to 16.7 and 6.4 ppb, respectively. After three months, the responses of p-PANI/CNT and n-PANI/CNT decreased by 19.1% and 11.3%, respectively. It was found that one-dimensional hierarchical structures and the deeper charge depletion layer enhanced by structural changes of PANI contributed to the sensitive and fast responses to NH3 and NO2. The formation process of the hierarchical PANI/CNT fibers, p-n transition, and the enhanced gas-sensing performance were systematically analyzed. This work also predicts the development prospects of cost-effective, high-performance PANI/CNT-based sensors.

20.
Cell Physiol Biochem ; 47(2): 774-783, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29807361

RESUMO

BACKGROUND/AIMS: Periodontitis is a prevalent chronic inflammatory disease caused by enhanced inflammation induced by dysbiotic microbes forming on subgingival tooth sites, which may disturb the balance of the microbial composition in the biofilm and finally result in the progressive destruction of the periodontal ligament and alveolar bone with periodontal pocket formation and/or gingival recession. METHODS: To elucidate the correlation between subgingival microbiome and IgAN incidence in CP (chronic periodontitis at severe levels) patients, subgingival plaque samples were collected from CP patients without IgAN (Control) and CP patients with IgAN (Disease). 16S rRNA sequencing and comparative analyses of plaque bacterial microbiome between Control and Disease were performed. RESULTS: Subgingival microbial diversity in Disease was a little higher than that in Control. Besides, significant differences were found in subgingival microbiome between Disease and Control. Compared with that in Control, at phylum level, the abundances of Proteobacteria and Actinobacteria were significantly higher while the abundances of Bacteroidetes, Fusobacteria, Spirochaetae, Synergistetes, and Saccharibacteria were significantly lower in Disease; at class level, the abundances of Betaproteobacteria, Bacilli, Actinobacteria, Flavobacteriia, and Gammaproteobacteria were significantly higher while the abundances of Bacteroidia, Fusobacteriia, Negativicutes, Clostridia, and Spirochaetes were significantly lower in Disease; at genus level, the abundances of Bergeyella, Capnocytophaga, Actinomyces, Corynebacterium, Comamonas, Lautropia, and Streptococcus were significantly higher while the abundances of Treponema and Prevotella were significantly lower in Disease. CONCLUSIONS: Our data indicated a correlation between the changes in subgingival microbial structure and IgAN incidence in CP patients, which might be used to predict IgAN incidence in CP patients.


Assuntos
Bactérias/genética , Periodontite Crônica/diagnóstico , Gengiva/microbiologia , Glomerulonefrite por IGA/diagnóstico , Microbiota , RNA Ribossômico 16S/metabolismo , Adulto , Bactérias/classificação , Bactérias/isolamento & purificação , Periodontite Crônica/complicações , Periodontite Crônica/microbiologia , Feminino , Glomerulonefrite por IGA/complicações , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Masculino , Filogenia , Análise de Componente Principal , RNA Ribossômico 16S/química , RNA Ribossômico 16S/genética , Análise de Sequência de DNA
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