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1.
Adv Sci (Weinh) ; : e2402616, 2024 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-38828766

RESUMO

Although possessing well-defined nanostructures and excellent multi-electron redox properties, polyoxometalate clusters have poor intrinsic electrical conductivity and are prone to aggregation due to large surface energy, which makes them difficult to be fully utilized when applying as electrode materials for lithium-ion batteries. In this paper, monodisperse K7MnV13O38 (MnV13) clusters are achieved by rationally utilizing nano-sized high conductive carbon dots (CDs) as stabilizers. Benefiting from the fully exposed redox sites of MnV13 clusters (high utilization rate) and sufficient interfaces with carbon dots (extra interfacial energy storage), the optimized MnV13/10CDs anode delivers a high discharge capacity up to 1348 mAh g-1 at a current density of 0.1 A g-1 and exhibits superb rate/cycling capabilities. Density functional theory (DFT) calculations verify that ionic archway channels are formed between MnV13 and CDs, eliminating the bandgap and greatly improving the electron/ion conductivity of MnV13 and CDs. This paper paves a brand-new way for synthesis of monodisperse clusters and maximization of extra interfacial energy storage.

2.
Adv Mater ; : e2407705, 2024 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-38925587

RESUMO

Polyoxometalates (POMs) have been considered as one of the most promising anode candidates for lithium-ion batteries (LIBs) in virtue of their high theoretical capacity and reversible multielectron redox properties. However, the poor intrinsic electronic conductivity, low specific surface area and high solubility in organic electrolytes hinder their widespread applications in LIBs. Herein, a novel hybrid nanomaterial is synthesized by co-assembling POMs and porphyrins (PMo12/CoTPyP) through a facile solvothermal method. The POMs clusters are stabilized by porphyrin units through electrostatic interactions, which simultaneously realizes the uniform dispersion of POMs and porphyrin units. Benefiting from the generated sub-1 nm channels for fast ion transport and the synergistic effect between evenly distributed PMo12 clusters and high-conductive CoTPyP units, the LIB based on the optimized PMo12/CoTPyP anode exhibits significant improved Li+ storage capability as well as superior rate and cycling performance. The results of density functional theory (DFT) simulations further reveal that the co-assembly of PMo12 and CoTPyP can accelerate the mobility of Li+ and electrons, which in turn promotes the enhancement of LIBs performance. This work paves a strategy for synthesizing POMs-based anode materials with simultaneously high dispersibility, redox activity and stability. This article is protected by copyright. All rights reserved.

3.
Heliyon ; 10(3): e25318, 2024 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-38356571

RESUMO

Objective: To review studies on digital medicine in cardiovascular diseases (CVD), discuss its development process, knowledge structure and research hotspots, and provide a perspective for researchers in this field. Methods: The relevant literature in recent 20 years (January 2004 to October 2022) were retrieved from the Web of Science Core Collection (WoSCC). CiteSpace was used to demonstrate our knowledge of keywords, co-references and speculative frontiers. VOSviewer was used to chart the contributions of authors, institutions and countries and incorporates their link strength into the table. Results: A total of 5265 English articles in set timespan were included. The number of publications increased steadily annually. The United States (US) produced the highest number of publications, followed by England. Most publications were from Harvard Medicine School, followed by Massachusetts General Hospital and Brigham Women's Hospital. The most authoritative academic journal was JMIR mHealth and uHealth. Noseworthy PA may have the highest influence in this intersected field with the highest number of citations and total link strength. The utilization of wearable mobile devices in the context of CVD, encompassing the identification of risk factors, diagnosis and prevention of diseases, as well as early intervention and remote management of diseases, has been widely acknowledged as a knowledge base and an area of current interest. To investigate the impact of various digital medicine interventions on chronic care and assess their clinical effectiveness, examine the potential of machine learning (ML) in delivering clinical care for atrial fibrillation (AF) and identifying early disease risk factors, as well as explore the development of disease prediction models using neural networks (NNs), ML and unsupervised learning in CVD prognosis, may emerge as future trends and areas of focus. Conclusion: Recently, there has been a significant surge of interest in the investigation of digital medicine in CVD. This initial bibliometric study offers a comprehensive analysis of the research landscape pertaining to digital medicine in CVD, thereby furnishing related scholars with a dependable reference to facilitate further progress in this domain.

4.
Eur J Med Res ; 28(1): 375, 2023 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-37749613

RESUMO

OBJECTIVE: To develop and validate a multivariate prediction model to estimate the risk of coronary heart disease (CHD) in middle-aged and elderly people and to provide a feasible method for early screening and diagnosis in middle-aged and elderly CHD patients. METHODS: This study was a single-center, retrospective, case-control study. Admission data of 932 consecutive patients with suspected CHD were retrospectively assessed from September 1, 2020 to December 31, 2021 in the Department of Integrative Cardiology at China-Japan Friendship Hospital. A total of 839 eligible patients were included in this study, and 588 patients were assigned to the derivation set and 251 as the validation set at a 7:3 ratio. Clinical characteristics of included patients were compared between derivation set and validation set by univariate analysis. The least absolute shrinkage and selection operator (Lasso) regression analysis method was performed to avoid collinearity and identify key potential predictors. Multivariate logistic regression analysis was used to construct a clinical prediction model with identified predictors for clinical practice. Bootstrap validation was used to test performance and eventually we obtained the actual model. And the Hosmer-Lemeshow test was carried out to evaluate the goodness-fit of the constructed model. The area under curve (AUC) of receiver operating characteristic (ROC), calibration curve, decision curve analysis (DCA), and clinical impact curve (CIC) were plotted and utilized with validation set to comprehensively evaluate the predictive accuracy and clinical value of the model. RESULTS: A total of eight indicators were identified as risk factors for the development of CHD in middle-aged and elderly people by univariate analysis. Of these candidate predictors, four key parameters were defined to be significantly related to CHD by Lasso regression analysis, including age (OR 1.034, 95% CI 1.002 ~ 1.067, P = 0.040), hemoglobin A1c (OR 1.380, 95% CI 1.078 ~ 1.768, P = 0.011), ankle-brachial index (OR 0.078, 95% CI 0.012 ~ 0.522, P = 0.009), and brachial artery flow-mediated vasodilatation (OR 0.848, 95% CI 0.726 ~ 0.990, P = 0.037). The Hosmer-Lemeshow test showed a good calibration performance of the clinical prediction model (derivation set, χ2 = 7.865, P = 0.447; validation set, χ2 = 11.132, P = 0.194). The ROCs of the nomogram in the derivation set and validation set were 0.722 and 0.783, respectively, suggesting excellent predictive power and suitable performance. The clinical prediction model presented a greater net benefit and clinical impact based on DCA and CIC analysis. CONCLUSION: Overall, the development and validation of the multivariate model combined the laboratory and clinical parameters of patients with CHD, which could be beneficial to the individualized prediction of middle-aged and elderly people, and helped to facilitate clinical assessments and decisions during treatment and management of CHD.


Assuntos
Doença das Coronárias , Modelos Estatísticos , Idoso , Pessoa de Meia-Idade , Humanos , Estudos de Casos e Controles , Prognóstico , Estudos Retrospectivos , Doença das Coronárias/diagnóstico , Doença das Coronárias/epidemiologia
5.
Chemistry ; 29(11): e202203419, 2023 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-36396601

RESUMO

To realize the direct and full use of the widely distributed solar energy, developing novel materials with superb photothermal conversion capability is essential. Although heteropoly blue has intrinsic outstanding solar absorption and photothermal conversion properties, its spectral absorption in the infrared region is weak. Here, composites of heteropoly blue and carbon nanotubes (HPB/CNTs) are synthesized depending on electrostatic interactions by facile microwave sonication and freeze-drying. The doped CNTs can dramatically improve the spectral absorption performance of HPB ontology in the infrared region. As a result, the light absorption of the optimized HPB/CNTs (20 %) reaches more than 95 % in the range of 200-2400 nm, showing promising prospects as high-performance photothermal conversion material in the applications of solar desalination and wastewater treatment.

6.
Front Cardiovasc Med ; 9: 891428, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36093165

RESUMO

Objective: To review the literature related to diabetic cardiomyopathy (DCM), and investigate research hotspots and development trends of this field in the relevant studies based on CiteSpace software of text mining and visualization in scientific literature. Methods: The relevant literature from the last 20 years was retrieved from the Web of Science (WoS) Core Collection database. After manual selection, each document record includes title, authors, year, organization, abstract, keywords, citation, descriptors, and identifiers. We imported the downloaded data into CiteSpace V (version 5.8.R2) to draw the knowledge map and conduct cooperative network analysis, cluster analysis, burst keyword analysis, and co-citation analysis. Results: After manual screening, there were 3,547 relevant pieces of literature published in the last 18 years (from 2004 to 2021), including 2,935 articles and reviews, which contained 15,533 references, and the number was increasing year by year. The publications of DCM were dedicated by 778 authors of 512 institutions in 116 countries. The People's Republic of China dominated this field (1,117), followed by the USA (768) and Canada (176). In general, most articles were published with a focus on "oxidative stress," "heart failure," "diabetic cardiomyopathy," "dysfunction," "cardiomyopathy," "expression," "heart," "mechanism," and "insulin resistance." Then, 10 main clusters were generated with a modularity Q of 0.6442 and a weighted mean silhouette of 0.8325 by the log-likelihood ratio (LLR) algorithm, including #0 heart failure, #1 perfused heart, #2 metabolic disease, #3 protective effect, #4 diabetic patient, #5 cardiac fibrosis, #6 vascular complication, #7 mitochondrial dynamics, #8 sarcoplasmic reticulum, and #9 zinc supplementation. The top five references with the strongest citation bursts include "Boudina and Abel", "Jia et al.", "Fang et al.", "Poornima et al.", and "Aneja et al.". Conclusion: The global field of DCM has expanded in the last 20 years. The People's Republic of China contributes the most. However, there is little cooperation among authors and institutions. Overall, this bibliometric study identified the hotspots in DCM research, including "stress state," "energy metabolism," "autophagy," "apoptosis," "inflammation," "fibrosis," "PPAR," etc. Thus, further research focuses on these topics that may be more helpful to identify, prevent DCM and improve prophylaxis strategies to bring benefit to patients in the near future.

7.
Zhongguo Zhong Yao Za Zhi ; 47(14): 3718-3722, 2022 Jul.
Artigo em Chinês | MEDLINE | ID: mdl-35850828

RESUMO

Traditional Chinese medicine(TCM) has its unique understanding of the etiology, pathogenesis, and risk factors of di-seases, and is advantageous in the study of risk prognosis.First recorded in Huangdi's Internal Classic, the TCM theory of treating di-sease before its onset has a long history.Supplemented and improved by the later generations of doctors, the TCM theory of treating di-sease before its onset has been applied to clinical practice and achieved good results.With the development of modern medicine, it has become a new trend to construct the risk prediction model integrating the research results of modern medicine with disease and syndrome combination of TCM characteristics.The construction of risk prediction model of disease and syndrome combination is conducive to early clinical screening and intervention, and provides ideas for the integration of TCM and western medicine.Coronary heart disease(CHD) is one of the common chronic diseases, and percutaneous coronary intervention(PCI) is an important therapeutic approach.In-stent restenosis(ISR) is a common complication after PCI, which seriously affects the outcome and prognosis of patients.Although some patients can be treated with balloon dilatation and endovascular stents, a significant number of patients still refuse secondary stenting intervention.The construction of risk prediction model of disease and syndrome combination for ISR after PCI can provide an effective tool for clinical risk prediction of ISR and indicators with TCM characteristics for early screening and intervention of people at a high risk of ISR, and guide clinical monitoring and intervention, which has certain clinical significance and reference value for the prevention and reduction of ISR.


Assuntos
Reestenose Coronária , Intervenção Coronária Percutânea , Reestenose Coronária/etiologia , Humanos , Intervenção Coronária Percutânea/efeitos adversos , Fatores de Risco , Stents/efeitos adversos , Resultado do Tratamento
8.
Front Psychol ; 13: 891126, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35602735

RESUMO

With the integration and penetration of digitization into healthcare services, the comprehensive health industrial market is developing flourishingly. Users are fast-changing the way of health communication. This study investigates psychosocial and technological factors on health information sharing adoption through social sharing services. Based on the unified theory of acceptance and use of technology, social influence theory, and innovation diffusion theory, we developed a hypothesized model for health information social sharing adoption (HISSA), and dimensions of attitude beliefs, control beliefs, and normative beliefs were created. We conducted an empirical study on the adoption intention using a survey for data collection. The results were obtained from 375 valid questionnaires, and their interactions were tested and analyzed using PLS-structural equation modeling. Results implied that (1) social identity of normative beliefs was the most critical variable affecting behavioral intention, which revealed the importance of psychosocial factors; (2) behavioral intention was also determined by user's performance expectancy, facilitating conditions, subjective norm; (3) personal innovativeness had a negative effect on behavioral intention and positive effect on effort expectancy; and (4) effort expectancy and social identity had a positive effect on performance expectancy. This study advances the understanding of social sharing for health and provides references for the development of both virtual health communities and social sharing services to upgrade their products from user's behavior and psychology. This empirical research model may also be useful for researchers who are interested in user's health information behavior.

9.
J Ethnopharmacol ; 280: 114420, 2021 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-34271116

RESUMO

ETHNOPHARMACOLOGICAL RELEVANCE: Andrographis paniculata (Burm.f.) Nees, a traditional Chinese herb, has been widely used in various Asian countries as a treatment for upper respiratory tract infections for centuries. AIM OF THE STUDY: Continuous inhalation of fine particulate matter (PM2.5) may induce various respiratory diseases. This study elucidated the protective effect of the effective part of Andrographis paniculata (Burm.f.) Nees (AEP) against PM2.5-induced lung injury and detailed the underlying mechanism. MATERIALS AND METHODS: Male Wistar rats were orally administered 0.5% sodium carboxymethylcellulose (CMC-Na), andrographolide (AG) (200 mg/kg) and AEP (100 mg/kg, 200 mg/kg and 400 mg/kg) once a day for 28 days. The rats were intratracheally instilled with PM2.5 suspension (8 mg/kg) every other day beginning on the 24th day for a total of 3 times. On the 29th day, bronchoalveolar lavage fluid (BALF) was collected to analyze the levels of lactate dehydrogenase (LDH), acid phosphatase (ACP), alkaline phosphatase (AKP), total proteins (TP), tumor necrosis factor α (TNF-α) and interleukin-6 (IL-6). Hematoxylin & eosin staining was conducted to evaluate the pathological changes in the lung tissues. The protein expression of NF-κB p65 in the lung tissues was analyzed by immunohistochemistry staining. Moreover, the nuclear translocation of NF-κB p65 and the phosphorylation of IκBα were analyzed by western blotting. RESULTS: PM2.5 exposure caused lung toxicity, which was characterized by pathological injury and increased levels of LDH, ACP, AKP and TP in BALF. Meanwhile, PM2.5 exposure induced lung inflammatory response, including infiltration of inflammatory cells and increased levels of inflammatory factors, such as TNF-α and IL-6 in BALF. AEP treatment significantly ameliorated the PM2.5-induced lung toxicity and the inflammatory response in rats. Moreover, AEP significantly inhibited the PM2.5-induced upregulation of NF-κB p65 protein expression, phosphorylation of IκBα and nuclear translocation of NF-κB p65 in lung tissue. Compared to AG, AEP exhibited a better ability to alleviate PM2.5-induced pathological damage and decrease the TP level in the BALF. CONCLUSION: AEP could be used to improve PM2.5-induced lung injury by modulating the NF-κB pathway, and multicomponent therapy with traditional Chinese medicine may be more effective than single-drug therapy.


Assuntos
Andrographis paniculata/química , Lesão Pulmonar/induzido quimicamente , NF-kappa B/metabolismo , Material Particulado/toxicidade , Fitoterapia , Extratos Vegetais/farmacologia , Animais , NF-kappa B/genética , Tamanho da Partícula , Extratos Vegetais/química , Ratos , Ratos Wistar
10.
Small ; 17(35): e2100683, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34310042

RESUMO

Designing highly selective and cost-effective electrocatalysts toward electrochemical carbon dioxide (CO2 ) reduction is crucial for desirable transformation of greenhouse gas into fuels or high-value chemical products. Here, the authors report intermetallic Cu3 Sn that is in situ formed and seamlessly integrated on self-supported bimodal nanoporous Cu skeleton (Cu3 Sn/Cu) via a spontaneous alloying of Sn and Cu as robust electrocatalyst for selective electroreduction of CO2 to CO. By virtue of Sn atoms strengthening CO adsorption on Cu atoms, the intermetallic Cu3 Sn has an intrinsic activity of ≈10.58 µA cm-2 , more than 80-fold higher than that of monometallic Cu. By virtue of hierarchical bicontinuous nanoporous Cu architecture facilitating electron transfer and CO2 and proton mass transport and offering high specific surface areas for full use of electroactive Cu3 Sn sites, the nanoporous Cu3 Sn/Cu hybrid electrodes produce CO at a low overpotential of 0.09 V, and exhibit high partial current density of ≈15 mA cm-2 geo at overpotential of 0.59 V, along with excellent stability and selectivity of 91.5% Faradaic efficiency. The outstanding electrochemical performance make them attractive alternatives to precious Au- and Ag-based electrocatalysts for building low-cost CO2 electrolyzers to selectively produce CO.

11.
Artigo em Inglês | MEDLINE | ID: mdl-33376502

RESUMO

SangQiQingXuan (SQQX) decoction is a pharmaceutical preparation exerting good therapeutic efficacy on high blood pressure (BP) and has widely been accepted in primarily hypertensive patients as a herbal formula prescribed by Professor Li Huang from China-Japan Friendship Hospital according to her 30-year clinical experience. A previous study showed that SQQX could reduce BP by decreasing levels of many inflammatory factors such as transforming growth factor beta (TGFß) and elevating peroxisome proliferator activated receptor (PPAR) expression. However, a research focusing on SQQX's protection against HTN from a metabolomic perspective has never been done before. This study aimed to figure out the metabolic profiling variations due to oral administration of SQQX in spontaneous hypertensive rat (SHR) models and to find out the optimal dosage of SQQX. SHR in the intervention group orally received SQQX extract of three doses, namely, the low- (5.25 g/kg/d), middle- (10.5 g/kg/d), and high-dosage groups (21 g/kg/d) for 90 days. Rats were sacrificed at the end of the experiment, and their serum was collected for further examination. Serum metabolic profiling variations were analyzed using ultraperformance liquid chromatography coupled with tandem mass spectrometry (UPLC/MS). Results showed that dealing with SQQX remarkably decreased systolic blood pressure (SBP) of SHRs and the high-dosage group was with the best therapeutic effect where a total of 11 metabolites were markedly changed in contrast to the model group. Orthogonal partial least square discriminant analysis (OPLS-DA) score plot showed that the 5 groups of serum samples were divided into 5 categories, and the metabolic trajectory of the high-dosage SQQX group was inclined to move to the control group. Glycochenodeoxycholic acid, nicotinamide-N-oxide, and tryptophan betaine might be biomarkers that specifically marked the protective effects of SQQX against high BP mainly involving in cholesterol metabolism, primary bile acid biosynthesis, bile secretion, and nicotinate and nicotinamide metabolism. To conclude, SQQX has a protective effect on SHR, which may be partially correlated to restoration of perturbed metabolism in serum.

12.
Front Pharmacol ; 11: 823, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32612527

RESUMO

OBJECTIVE: Vascular endothelium plays a fundamental role in regulating endothelial dysfunction, resulting in structural changes that may lead to adverse outcomes of hypertension. The aim of this study was to systematically evaluate the effect of a combination of Chinese herbal medicine (CHM) and Western medicine on vascular endothelial function in patients with hypertension. METHODS: We systematically searched the literature for studies published in Chinese and English in PubMed, Embase, Cochrane Central Register of Controlled Trials, Chinese Biomedical Literature Database, China Knowledge Resource Integrated Database, Wanfang Data, and China Science and Technology Journal Database. Databases were searched using terms concerning or describing CHM, hypertension, vascular endothelium, and randomized controlled trials. RevMan 5.3.0 was used for data analysis. If the included studies were sufficiently homogeneous, quantitative synthesis was performed; if studies with different sample sizes and blind methods were used, subgroup analyses were performed. GRADEpro was selected to grade the current evidence to reduce bias in our findings. RESULTS: In this review, 30 studies with 3,235 patients were enrolled. A relatively high selection and a performance bias were noted by risk of bias assessments. Meta-analysis showed that the combination of CHM and conventional Western medicine was more efficient than conventional Western medicine alone in lowering blood pressure (risk ratio, 1.21; 95% CI, 1.16 to 1.26) and increasing nitric oxide (95% CI, 1.24 to 2.08; P < 0.00001), endothelin-1 (95% CI, -1.71 to -1.14; P < 0.00001), and flow-mediated dilation (95% CI, 0.98 to 1.31; P <0.00001). No significant difference was observed between the combination of CHM and conventional Western medicine and conventional Western medicine alone for major cardiovascular and cerebrovascular events. CHM qualified for the treatment of hypertension. The GRADEpro presented with low quality of evidence for the available data. CONCLUSION: CHM combined with conventional Western medicine may be effective in lowering blood pressure and improving vascular endothelial function in patients with hypertension. To further confirm this, more well-designed studies with large sample sizes, strict randomization, and clear descriptions about detection and reporting processes are warranted.

13.
Nat Commun ; 11(1): 2940, 2020 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-32522988

RESUMO

Developing robust nonprecious electrocatalysts towards hydrogen/oxygen evolution reactions is crucial for widespread use of electrochemical water splitting in hydrogen production. Here, we report that intermetallic Co3Mo spontaneously separated from hierarchical nanoporous copper skeleton shows genuine potential as highly efficient electrocatalysts for alkaline hydrogen/oxygen evolution reactions in virtue of in-situ hydroxylation and electro-oxidation, respectively. The hydroxylated intermetallic Co3Mo has an optimal hydrogen-binding energy to facilitate adsorption/desorption of hydrogen intermediates for hydrogen molecules. Associated with high electron/ion transport of bicontinuous nanoporous skeleton, nanoporous copper supported Co3Mo electrodes exhibit impressive hydrogen evolution reaction catalysis, with negligible onset overpotential and low Tafel slope (~40 mV dec-1) in 1 M KOH, realizing current density of -400 mA cm-2 at overpotential of as low as 96 mV. When coupled to its electro-oxidized derivative that mediates efficiently oxygen evolution reaction, their alkaline electrolyzer operates with a superior overall water-splitting output, outperforming the one assembled with noble-metal-based catalysts.

14.
Nat Commun ; 11(1): 1634, 2020 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-32242024

RESUMO

Metallic zinc is an attractive anode material for aqueous rechargeable batteries because of its high theoretical capacity and low cost. However, state-of-the-art zinc anodes suffer from low coulombic efficiency and severe dendrite growth during stripping/plating processes, hampering their practical applications. Here we show that eutectic-composition alloying of zinc and aluminum as an effective strategy substantially tackles these irreversibility issues by making use of their lamellar structure, composed of alternating zinc and aluminum nanolamellas. The lamellar nanostructure not only promotes zinc stripping from precursor eutectic Zn88Al12 (at%) alloys, but produces core/shell aluminum/aluminum sesquioxide interlamellar nanopatterns in situ to in turn guide subsequent growth of zinc, enabling dendrite-free zinc stripping/plating for more than 2000 h in oxygen-absent aqueous electrolyte. These outstanding electrochemical properties enlist zinc-ion batteries constructed with Zn88Al12 alloy anode and KxMnO2 cathode to deliver high-density energy at high levels of electrical power and retain 100% capacity after 200 hours.

15.
Research (Wash D C) ; 2020: 2987234, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32161925

RESUMO

Designing highly active and robust platinum-free electrocatalysts for hydrogen evolution reaction is vital for large-scale and efficient production of hydrogen through electrochemical water splitting. Here, we report nonprecious intermetallic Cu5Zr clusters that are in situ anchored on hierarchical nanoporous copper (NP Cu/Cu5Zr) for efficient hydrogen evolution in alkaline medium. By virtue of hydroxygenated zirconium atoms activating their nearby Cu-Cu bridge sites with appropriate hydrogen-binding energy, the Cu5Zr clusters have a high electrocatalytic activity toward the hydrogen evolution reaction. Associated with unique architecture featured with steady and bicontinuous nanoporous copper skeleton that facilitates electron transfer and electrolyte accessibility, the self-supported monolithic NP Cu/Cu5Zr electrodes boost violent hydrogen gas release, realizing ultrahigh current density of 500 mA cm-2 at a low potential of -280 mV versus reversible hydrogen electrode, with exceptional stability in 1 M KOH solution. The electrochemical properties outperform those of state-of-the-art nonprecious metal electrocatalysts and make them promising candidates as electrodes in water splitting devices.

16.
Adv Mater ; 32(10): e1907214, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31999014

RESUMO

Designing highly active and robust electrocatalysts for oxygen evolution reaction (OER) is crucial for many renewable energy storage and conversion devices. Here, self-supported monolithic hybrid electrodes that are composed of bimetallic cobalt-molybdenum nitride nanosheets vertically aligned on 3D and bicontinuous nanoporous gold (NP Au/CoMoNx ) are reported as highly efficient electrocatalysts to boost the sluggish reaction kinetics of water oxidation in alkaline media. By virtue of the constituent CoMoNx nanosheets having large accessible CoMoOx surface with remarkably enhanced electrocatalytic activity and the nanoporous Au skeleton facilitating electron transfer and mass transport, the NP Au/CoMoNx electrode exhibits superior OER electrocatalysis in 1 m KOH, with low onset overpotential (166 mV) and Tafel slope (46 mV dec-1 ). It only takes a low overpotential of 370 mV to reach ultrahigh current density of 1156 mA cm-2 , ≈140-fold higher than free CoMoNx nanosheets. The electrocatalytic performance makes it an attractive candidate as the OER catalyst in the water electrolysis.

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