Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 166
Filtrar
1.
Respir Res ; 21(1): 272, 2020 Oct 19.
Artigo em Inglês | MEDLINE | ID: mdl-33076908

RESUMO

BACKGROUND: The longer upper airway is more collapsible during sleep. This study aims to reveal relationships among upper airway length, weight, and obstructive sleep apnea (OSA), particularly to answer why the upper airway of OSA patients is longer than that of healthy people and why some obese people suffer from OSA while others do not. METHODS: We perform head and neck MRI on male patients and controls, and measure > 20 morphological parameters, including several never before investigated, to quantify the effect of weight change on upper airway length. RESULTS: The upper airway length is longer in patients and correlates strongly to body weight. Weight increase leads to significant fat infiltration in the tongue, causing the hyoid to move downward and lengthen the airway in patients. The apnea-hypopnea index (AHI) strongly correlates to airway length and tongue size. Surprisingly, a distance parameter h and angle ß near the occipital bone both show significant differences between healthy males and patients due to their different head backward tilt angle, and strongly correlates with AHI. The contributions of downward hyoid movement and head tilt on airway lengthening are 67.4-80.5% and19.5-32.6%, respectively, in patients. The parapharyngeal fat pad also correlates strongly with AHI. CONCLUSIONS: The findings in this study reveal that the amount of body weight and distribution of deposited fat both affect airway length, and therefore OSA. Fat distribution plays a larger impact than the amount of weight, and is a better predictor of who among obese people are more prone to OSA.

2.
J Sci Food Agric ; 2020 Sep 24.
Artigo em Inglês | MEDLINE | ID: mdl-32974893

RESUMO

Food loss of fruit and vegetables caused by postharvest diseases is a major issue worldwide. The method used to prevent and control postharvest diseases is usually to use chemical fungicides, but long-term and large-scale use will make the pathogens resistant and potentially have a negative impact on human health and the ecological environment. Therefore, finding a safe and effective biological control method instead of chemical control is a hot research topic in recent years. Endophytes, colonizing plants asymptomatically, can promote the growth of the hosts and enhance their resistance. The use of endophytes as biological control agents for postharvest diseases of fruit and vegetables has attracted increasing attention in the last 20 years. Compared with chemical control, endophytes have the advantages of being more environmentally friendly, sustainable, and safer. However, there are relatively few relevant studies, so herein we summarize the available literature. This review focuses mainly on the recent progress of using endophytes to enhance the resistance of postharvest fruit and vegetables to diseases, with the emphasis on the possible mechanisms and the potential applications. Furthermore, this article suggests future areas for study using antagonistic endophytes to prevent and control fruit and vegetable postharvest diseases: (i) screening more potential broad-spectrum anti-pathogen endophytes and their metabolic active substances by the method of macrogenomics; (ii) elucidating the underlining molecular mechanism among endophytes, harvested vegetables and fruit, pathogens, and microbial communities; (iii) needing more application research to overcome the difficulties of commercialization practice. © 2020 Society of Chemical Industry.

3.
Chin J Integr Med ; 2020 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-32975759

RESUMO

OBJECTIVE: To investigate the effect of Kangquan Recipe (, KQR) on bone morphogenetic protein and activin membrane-bound inhibitor (BAMBI) expression and its mechanism in rats with benign prostatic hyperplasia (BPH). METHODS: Forty-eight male Sprague-Dawley rats were divided into 6 groups using a random number table, with 8 in each group: the normal group (normal saline 10 mL/kg), the model group (normal saline 10 mL/kg), the finasteride group (0.5 mg/kg), the low-dose KQR group (3.5 g/kg), the middle-dose KQR group (7 g/kg), and the high-dose KQR group (14 g/kg). The 40 rats were subcutaneously injected with testosterone propionate after castration for 30 days to establish the BPH rat model except for those in the normal group. At the same time, the corresponding drugs were administered by gavage for 30 consecutive days. The effects of different doses of KQR on the protate wet weight, prostate volume and prostate index (PI) were observed. The changes in histopathology were monitored with hematoxylin-eosin staining. BAMBI protein and mRNA expression contents were determined by Western blot and quantitative real-time polymerase chain reaction, respectively. RESULTS: All doses of KQR could decrease prostatic epithelial tissue proliferation. Compared to the model group, the high and middle-dose KQR significantly reduced prostate wet weight, prostate volume and PI; increased BAMBI protein expression in the hypothalamus, pituitary and prostate tissue; all doses of KQR up-regulated BAMBI mRNA expression in serum, prostatic fluid and prostate tissue (P<0.05 or P<0.01). CONCLUSIONS: KQR could inhibit the proliferation of rat prostatic tissue, promote BAMBI protein expression in the hypothalamic-pituitary-prostate of rats with BPH; and increase BAMBI mRNA expression in the blood, prostatic fluid and prostate tissue of rats with BPH, showing a dose-effect relationship. KQR can be used as a potential drug for the treatment of BPH.

4.
Toxicol Appl Pharmacol ; 407: 115247, 2020 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-32971067

RESUMO

Psoriasis is a highly prevalent chronic dermatitis, characterized by widespread skin inflammation and spontaneous itch. Given the adverse reactions and drug dependence of current treatment, new drugs for psoriasis therapy are urgently needed. This study aims to explore the anti-psoriatic effects of thymol in imiquimod (IMQ) induced mice, and elucidate the potential mechanisms for its therapeutic activities. Thymol reduced the scratching behavior in IMQ mice, and activated Ca2+ response in cervical DRG neurons via TRPM8 channel. Also, thymol alleviated psoriasis-like skin lesions, and attenuated the enhanced infiltration of dermal neutrophils, dendritic cells (DCs) and Th17 cells. In addition, it reversed the upregulated expression of pro-inflammatory cytokines in the skin (TNF-α, IL-22, IL-23, IL-17A, IL-17F, IL-17C, IL-6, IL-1ß and IFN-γ) and serum (TNF-α, IL-6, IL-1ß, IL-17A and IFN-γ). Our results indicated that thymol can effectively ameliorate pruritus and the symptoms of psoriasis-like inflammation induced by IMQ, which makes it a promising drug for the treatment of psoriasis.

5.
FEBS Open Bio ; 10(10): 2182-2190, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32865342

RESUMO

Prohibitin (PHB) is a highly conserved, ubiquitously expressed, multifunctional protein with a well-characterized function as a chaperone-stabilizing mitochondrial proteins. Recently it was reported that nuclear PHB participates in HIRA chaperone complexes and regulates downstream gene expression via cell cycle independent deposition of H3.3 into DNA. However, the role of PHB in cancer progression remains controversial with conflicting reports in the literature, perhaps due to its cell type-dependent subcellular localization. Here, we report that the increased expression of nuclear PHB is positively correlated with metastasis of breast cancer cell lines. We showed PHB participates in the HIRA complex by interacting with HIRA through the linker region of the PHB domain and stabilizes all components of the HIRA complex in breast cancer. Overexpression of nuclear PHB resulted in a higher enrichment of histone H3.3 deposited by the HIRA complex at the promoters of mesenchymal markers. This coincided with an increased gene expression level of these markers, and induced EMT in breast cancer. Overall, these molecular and structural mechanisms suggest that nuclear PHB could hold promise as a potential target for cancer therapy.

6.
Artigo em Inglês | MEDLINE | ID: mdl-32864791

RESUMO

Metastable materials are promising because of their catalytic properties, high-energy structure, and unique electronic environment. However, the unstable nature inherited from the metastability hinders further performance improvement and practical applications of these materials. Herein, this limitation is successfully addressed by constructing an in situ polymorphism interface (inf) between the metastable hexagonal-close-packed (hcp) phase and its stable counterpart (face-centered cubic, fcc) in cobalt-nickel (CoNi) alloy. Calculations reveal that the interfacial synergism derived from the hcp and fcc phases lowers the formation energy and enhances stability. Consequently, the optimized CoNi-inf exhibits an exceptionally low potential of 72 mV at 10 mA cm-2 and a Tafel slope of 57 mV dec-1 for the hydrogen evolution reaction (HER) in 1.0 m KOH. Furthermore, it is superior to most state-of-the-art non-noble-metal-based HER catalysts. No noticeable activity decay or structural changes are observed even over 14 h of catalysis. The computational simulation further rationalizes that the interface of CoNi-inf with a suitable d-band center provides uniform sites for hydrogen adsorption, leading to a distinguished HER catalytic activity. This work, therefore, presents a new route for designing metastable catalysts for potential energy conversion.

7.
Sci Adv ; 6(31): eaba9731, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32832686

RESUMO

The methanol crossover effect in direct methanol fuel cells (DMFCs) can severely reduce cathodic oxygen reduction reaction (ORR) performance and fuel efficiency. As a result, developing efficient catalysts with simultaneously high ORR activity and excellent antipoisoning methanol capability remains challenging. Here, we report a class of Pd-Te hexagonal nanoplates (HPs) with a Pd20Te7 phase that simultaneously overcome the activity and methanol-tolerant issues in alkaline DMFC. Because of the specific arrangement of Pd atoms deviated from typical hexagonal close-packing, Pd-Te HPs/C displays extraordinary methanol tolerance with high ORR performance compared with commercial Pt/C. DFT calculations reveal that the high performance of Pd-Te HPs can be attributed to the breakthrough of the linear relationship between OOH* and OH* adsorption, which leaves sufficient room to improve the ORR activity but suppresses the methanol oxidation reaction. The concurrent high ORR activity and excellent methanol tolerance endow Pd-Te HPs as practical electrocatalysts for DMFC and beyond.

8.
Toxicol Appl Pharmacol ; 405: 115209, 2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-32835761

RESUMO

In this work, we aimed to investigate whether oxymatrine exerts its anti-pruritic and anti-inflammatory efficacy in the imiquimod-induced psoriasis mice and the related mechanism. We established the psoriasis model by applying the imiquimod ointment topically and oxymatrine was injected intraperitoneally as the treatment. The behavior and skin morphology results indicated that oxymatrine inhibits imiquimod-induced pruritus alleviating keratinization of skin and inflammatory infiltration. Moreover, we examined the expression of various indicators and found heat shock protein (HSP) 90 and 60 upregulated in model group, which were reversed in oxymatrine treated groups. Molecular docking and the studies in vivo confirmed that HSP90 and HSP60 participate in the inhibitory effect of oxymatrine on the phenotypes of psoriasis mice. Mechanically, immunofluorescence staining demonstrated that oxymatrine-induced downregulation of HSP90 and HSP60 was mainly in keratinocytes. In vitro results showed that oxymatrine decreases the expression of HSP90 and HSP60 upregulated by TNF-α and IFN-γ in HaCaTs cells and the siRNA mediated HSP90 and HSP60 silencing reverses inflammation inhibited by oxymatrine. Taken together, these results indicate that oxymatrine relieves psoriasis pruritic and inflammation by inhibiting the expression of HSP90 and HSP60 in keratinocytes through MAPK signaling pathway.

9.
Plant Dis ; 104(9): 2338-2345, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32697657

RESUMO

Grape production is increasing globally and so are problems with downy mildew, one of the main constraints in grape production. Downy mildew on grape is caused by Plasmopara viticola, an obligate biotrophic pathogen belonging to the oomycetes. Control of the disease is usually performed by fungicide applications, of which carboxylic acid amide (CAA) fungicides represent one of the most widely used groups of fungicides. Our previous research showed that the extensive application of CAA fungicides can result in fungicide resistance and in China, CAA-resistant isolates of P. viticola were collected from the field in 2014. To monitor the distribution and spread of CAA fungicide resistance, we developed a TaqMan-minor groove binder (MGB) real-time PCR-based method designed on a functional mutation in the PvCesA3 gene that allows efficient identification of CAA fungicide resistant and sensitive genotypes. The assay was validated on 50 isolates using Sanger sequencing and fungicide bioassays and exploited in a comprehensive survey comprising 2,227 single-sporangiophore isolates from eight major grapevine regions in China. We demonstrate that CAA fungicide resistance in P. viticola is widespread in China. On average, 53.3% of the isolates were found to be resistant, but marked differences were found between locations with percentages of resistant isolates varying from 0.3 to 96.6%. Furthermore, the frequency of CAA-resistant isolates was found to be significantly correlated with the exposure to CAA fungicides (P < 0.05). We further discussed the possibilities to apply the TaqMan-MGB real-time PCR assay to assess the frequency of fungicide-resistant P. viticola isolates in each region or vineyard, which would facilitate the correct choice of fungicide for grape downy mildew and resistance management strategies.


Assuntos
Farmacorresistência Fúngica , Oomicetos/genética , Amidas , Ácidos Carboxílicos , China , Reação em Cadeia da Polimerase em Tempo Real
10.
Medicine (Baltimore) ; 99(27): e19811, 2020 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-32629622

RESUMO

INTRODUCTION: Nosocomial Enterococcus faecium (E faecium) infections are common among immunocompromised patients; however, sepsis caused by E faecium is rarely encountered in the clinical setting. PATIENT CONCERNS: A 69-year-old woman with a previous history of tuberculosis (TB), developed symptoms of recurrent fever, paroxysmal cough, and exertional dyspnea for over 2 months before she presented to the hospital. DIAGNOSIS: The patient was initially misdiagnosed with recurrent TB, and did not respond to anti-TB therapy. Culture results of blood, endotracheal necrotic tissue, and urine confirmed a diagnosis of multifocal E faecium infection. INTERVENTIONS: On definitive diagnosis, the patient received intensive antimicrobial combination treatment with linezolid, teicoplanin, caspofungin, and voriconazole on the basis of antimicrobial susceptibility results. OUTCOMES: After transient improvement, the patient's condition deteriorated due to secondary infections, and the patient died after discharge against medical advice. CONCLUSION: E faecium bacteremia may cause sepsis in immunocompromised patients, and has a high mortality rate. Careful pathogen detection and early initiation of treatment is crucial to good patient outcome.


Assuntos
Enterococcus faecium/isolamento & purificação , Infecções por Bactérias Gram-Positivas/diagnóstico , Sepse/microbiologia , Idoso , Antibacterianos/uso terapêutico , Diagnóstico Diferencial , Feminino , Infecções por Bactérias Gram-Positivas/complicações , Infecções por Bactérias Gram-Positivas/tratamento farmacológico , Humanos , Sepse/tratamento farmacológico , Tuberculose Pulmonar/diagnóstico
13.
Cancer Biother Radiopharm ; 35(8): 586-595, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32486841

RESUMO

Background: Hepatocellular carcinoma (HCC) poses a growing threat to humans due to poor prognosis. Extract of stellera chamaejasme L. (ESC) is reported to inhibit metastasis of HCC. However, the underlying mechanism of ESC in regulating the progression of HCC needs to be further investigated. Methods: 3-(4, 5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay was used to measure cell proliferation. Flow cytometry was employed to check cell apoptosis. Transwell assay was conducted to assess the abilities of cell migration and invasion. The protein levels of proliferating cell nuclear antigen, cleaved caspase 3 (c-caspase 3), E-cadherin, janus kinase 1 (JAK1), signal transducer and activator of transcription 3 (STAT3), and phosphorylated STAT3 were detected by Western blot. The interaction between miR-134-5p and JAK1 was predicted by starBase, which was verified by the dual-luciferase reporter assay and RNA pull-down assay. The messenger RNA levels of miR-134-5p and JAK1 were determined by quantitative real-time polymerase chain reaction. Results: The results showed that the higher concentration or the longer time treatment of ESC led to the lower survival rate of HCC cells. Besides, ESC induced apoptosis and impeded migration and invasion of HCC cells. Moreover, downregulation of miR-134-5p inverted the effects of ESC-mediated repression on HCC progression. Further studies indicated that miR-134-5p targeted the 3'-untranslated region (3'UTR) of JAK1 and reversed JAK1-mediated impacts on HCC progression. Simultaneously, ESC inactivated JAK1/STAT3 pathway by regulating the expression of miR-134-5p. Conclusion: ESC suppressed HCC progression by upregulating the expression of miR-134-5p and blocking JAK1/STAT3 pathway.

14.
Nano Lett ; 2020 Jun 09.
Artigo em Inglês | MEDLINE | ID: mdl-32515969

RESUMO

Single-atom site catalysts (SACs) have aroused enormous attention and brought about new opportunities for many applications. Herein, we report a versatile strategy to rhodium single atomic site catalysts (Rh SAC) by a facile cation exchange reaction. Remarkably, the Rh SAC modified CuO nanowire arrays on copper foam (Rh SAC-CuO NAs/CF) shows unprecedented alkaline oxygen evolution reaction (OER) activity with a high current density of 84.5 mA cm-2 @1.5 V vs. reversible hydrogen electrode (RHE), 9.7 times of that of the commercial Ir/C/CF. For the alkaline hydrogen evolution reaction (HER), Rh SAC-CuO NAs/CF drives a high current density of 81.3 mA cm-2 at the potential of -0.15 V vs. RHE, which is even higher than that of the benchmark Pt/C/CF (62.2 mA cm-2). More strikingly, when used as anode and cathode for overall water splitting, the Rh SAC-CuO NAs/CF || Rh SAC-CuO NAs/CF can achieve 10 mA cm-2 at only 1.51 V. Density functional theory calculations reveal that the high OER and HER intrinsic catalytic activities result from moderate adsorption energy of intermediates on Rh SAC. Finally, we demonstrate the general synthesis of different single-atom noble-metal catalysts on CuO NAs (M SAC-CuO NAs/CF, where M = Ru, Ir, Os and Au).

15.
J Colloid Interface Sci ; 576: 176-185, 2020 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-32417682

RESUMO

Volume expansion and poor conductivity result in poor cyclability and low rate capability, which are the major challenges of transition-metal oxide as anode materials for sodium-ion batteries (SIBs). Herein, N-doped carbon encapsulated CoMoO4 (CoMoO4@NC) nanorods are developed as excellent anode materials for SIBs with long-cycle life. The N-doped carbon shells serve as buffer to accommodate severe volume changes during sodiation/desodiation, and at the same time improve electronic conductivity and activate surface sites of CoMoO4. The optimized composite presents rapid reaction kinetics and excellent cycle stability. Even at a high current density of 1 A g-1, it still shows long-cycle life and maintains specific capacity of 190 mAh g-1 after 3200 cycles. Furthermore, CoMoO4@NC anode is applied to match with Na3V2(PO4)3 cathode to assemble full-cells, in which it accomplishes reversible capacity of 152 mAh g-1 after 100 cycles, with capacity retention of 75% at a current density of 1 A g-1, highlighting the practical application for SIBs.

16.
Adv Mater ; 32(24): e2001267, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32390237

RESUMO

Electrocatalytic nitrogen reduction reaction (NRR) is a promising process relative to energy-intensive Haber-Bosch process. While conventional electrocatalysts underperform with sluggish paths, achieving dissociation of N2 brings the key challenge for enhancing NRR. This study proposes an effective surface chalcogenation strategy to improve the NRR performance of pristine metal nanocrystals (NCs). Surprisingly, the NH3 yield and Faraday efficiency (FE) (175.6 ± 23.6 mg h-1 g-1 Rh and 13.3 ± 0.4%) of Rh-Se NCs is significantly enhanced by 16 and 15 times, respectively. Detailed investigations show that the superior activity and high FE are attributed to the effect of surface chalcogenation, which not only can decrease the apparent activation energy, but also inhibit the occurrence of the hydrogen evolution reaction (HER) process. Theoretical calculations reveal that the strong interface strain effect within core@shell system induces a critical redox inversion, resulting in a rather low valence state of Rh and Se surface sites. Such strong correlation indicates an efficient electron-transfer minimizing NRR barrier. Significantly, the surface chalcogenation strategy is general, which can extend to create other NRR metal electrocatalysts with enhanced performance. This strategy open a new avenue for future NH3 production for breakthrough in the bottleneck of NRR.

17.
Artigo em Inglês | MEDLINE | ID: mdl-32453471

RESUMO

Herein, we developed a partially controlled pyrolysis strategy to create evenly distributed NiO nanoparticles within NiFe-MOF nanosheets (MOF NSs) for electrochemical synthesis of H2 O2 by a two-electron oxygen reduction reaction (ORR). The elemental Ni can be partially transformed to NiO and uniformly distributed on the surface of the MOF NSs, which is crucial for the formation of the particular structure. The optimized MOF NSs-300 exhibits the highest activity for ORR with near-zero overpotential and excellent H2 O2 selectivity (ca. 99 %) in 0.1 m KOH solution. A high-yield H2 O2 production rate of 6.5 mol gcat -1 h-1 has also been achieved by MOF NSs-300 in 0.1 m KOH and at 0.6 V (vs. RHE). In contrast to completely pyrolyzed products, the enhanced catalytic activities of partially pyrolyzed MOF NSs-300 originates mainly from the retained MOF structure and the newly generated NiO nanoparticles, forming the coordinatively unsaturated Ni atoms and tuning the performance towards electrochemical H2 O2 synthesis.

18.
Sci Total Environ ; 723: 138171, 2020 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-32392684

RESUMO

Volatile organic compounds (VOCs) play a crucial role in modulating air pollution by ozone and fine particles, particularly in urban areas. While in recent years short-term intervention actions for better air quality during big events in China did present good opportunities to examine the effectiveness of control measures in reducing anthropogenic VOCs emission, it is highly challenging to interpret the real effect of a specific control measure based on field monitoring data when a cocktail of control measures were adopted. Here we took the air quality intervention actions during the 16th Asian Games (AG) in Guangzhou as a case study to explore the impact of short-term multiple measures on VOCs reduction. The average mass concentrations of VOCs decreased by 52-68% during the AG. These percentages could not reflect emission reduction rates as the concentration might be also heavily impacted by dispersion conditions. Diagnostic ratios, such as methyl tert-butyl ether to carbon monoxide (MTBE/CO) and i-pentane/CO, decreased by over 60% during the AG, suggesting a substantial reduction in gasoline related emissions. A method linking emission reduction rates of two sources with their contribution percentages before and during the AG by using a receptor model was further formulated. With the available reduction rate of 34% for vehicular exhaust obtained during the traffic restriction drill in our previous study, VOCs emissions from gasoline evaporation and solvent use reduced by 45.7% and 13.6% during the AG, respectively. Total VOCs emissions decreased by 25.3% on average during the AG, and the emission control of vehicular exhaust, oil evaporation, and solvent use accounted for 17.0%, 6.3% and 2.0% of total VOCs emission reduction, respectively. This study presented an observed-based method with diagnostic/quantitative approaches to single out the effectiveness of each control measures in reducing VOCs emissions.

19.
Chem Soc Rev ; 49(10): 3072-3106, 2020 May 26.
Artigo em Inglês | MEDLINE | ID: mdl-32309830

RESUMO

Metallic nanostructures with low dimensionality (one-dimension and two-dimension) possess unique structural characteristics and distinctive electronic and physicochemical properties including high aspect ratio, high specific surface area, high density of surface unsaturated atoms and high electron mobility. These distinctive features have rendered them remarkable advantages over their bulk counterparts for surface-related applications, for example, electrochemical water splitting. In this review article, we highlight the recent research progress in low-dimensional metallic nanostructures for electrochemical water splitting including hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). Fundamental understanding of the electrochemistry of water splitting including HER and OER is firstly provided from the aspects of catalytic mechanisms, activity descriptors and property evaluation metrics. Generally, it is challenging to obtain low-dimensional metallic nanostructures with desirable characteristics for HER and OER. We hereby introduce several typical methods for synthesizing one-dimensional and two-dimensional metallic nanostructures including organic ligand-assisted synthesis, hydrothermal/solvothermal synthesis, carbon monoxide confined growth, topotactic reduction, and templated growth. We then put emphasis on the strategies adopted for the design and fabrication of high-performance low-dimensional metallic nanostructures for electrochemical water splitting such as alloying, structure design, surface engineering, interface engineering and strain engineering. The underlying structure-property correlation for each strategy is elucidated aiming to facilitate the design of more advanced electrocatalysts for water splitting. The challenges and perspectives for the development of electrochemical water splitting and low-dimensional metallic nanostructures are also proposed.

20.
Adv Mater ; 32(22): e1906477, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32323370

RESUMO

The electroreduction of small molecules to high value-added chemicals is considered as a promising way toward the capture and utilization of atmospheric small molecules. Discovering cheap and efficient electrocatalysts with simultaneously high activity, selectivity, durability, and even universality is desirable yet challenging. Herein, it is demonstrated that Bi2 Te3 nanoplates (NPs), cheap and noble-metal-free electrocatalysts, can be adopted as highly universal and robust electrocatalysts, which can efficiently reduce small molecules (O2 , CO2 , and N2 ) into targeted products simultaneously. They can achieve excellent activity, selectivity and durability for the oxygen reduction reaction with almost 100% H2 O2 selectivity, the CO2 reduction reaction with up to 90% Faradaic efficiency (FE) of HCOOH, and the nitrogen reduction reaction with 7.9% FE of NH3 . After electrochemical activation, an obvious Te dissolution happens on the Bi2 Te3 NPs, creating lots of Te vacancies in the activated Bi2 Te3 NPs. Theoretical calculations reveal that the Te vacancies can modulate the electronic structures of Bi and Te. Such a highly electroactive surface with a strong preference in supplying electrons for the universal reduction reactions improves the electrocatalytic performance of Bi2 Te3 . The work demonstrates a new class of cheap and versatile catalysts for the electrochemical reduction of small molecules with potential practical applications.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA