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1.
Small ; 20(13): e2306998, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37963849

RESUMO

Memristor-based artificial synapses are regarded as the most promising candidate to develop brain-like neuromorphic network computers and overcome the bottleneck of Von-Neumann architecture. Violet phosphorus (VP) as a new allotrope of available phosphorus with outstanding electro-optical properties and stability has attracted more and more attention in the past several years. In this study, large-scale, high-yield VP microfiber vertical arrays have been successfully developed on a Sn-coated graphite paper and are used as the memristor functional layers to build reliable, low-power artificial synaptic devices. The VP devices can well mimic the major synaptic functions such as short-term memory (STM), long-term memory (LTM), paired-pulse facilitation (PPF), spike timing-dependent plasticity (STDP), and spike rate-dependent plasticity (SRDP) under both electrical and light stimulation conditions, even the dendritic synapse functions and simple logical operations. By virtue of the excellent performance, the VP artificial synapse devices can be conductive to building high-performance optic-neural synaptic devices simulating the human-like optic nerve system. On this basis, Pavlov's associative memory can be successfully implemented optically. This study provides a promising approach for the design and manufacture of VP-based artificial synaptic devices and outlines a direction with multifunctional neural devices.

2.
Inorg Chem ; 62(4): 1549-1560, 2023 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-36637247

RESUMO

There are relatively few reports on the combination of viologen and polyoxometalates (POMs). Herein, we successfully synthesized three viologen-POM-based compounds by in situ transformation of ligands under hydrothermal conditions, namely, {MII(1,4-cby)2[H2(γ-Mo8O26)]}·nH2O (1: M = Ni, n = 4; 2: M = Co, n = 6), and [NiII(1,3-cby)(H2O)4(ß-Mo8O26)0.5]·2H2O (3) (1,4-cby·Cl = 1-(4-carboxy-benzyl)-[4,4']bipyridinyl-1-ium, 1,3-cby·Cl = 1-(3-carboxy-benzyl)-[4,4']bipyridinyl-1-ium). Isostructural compounds 1 and 2 exhibit two-dimensional (2D) layer structures with POMs as linking nodes, while compound 3 shows a one-dimensional (1D) metal-organic chain with dissociative POM anions. When the temperature increases, compounds 1-3 show good reversible thermochromism properties and also have a fluorescence quenching effect. Moreover, compounds 1-3 can also be used as detectors for organic amines, especially in the atmosphere of ammonia, ethylenediamine, and diethylamine with an obvious discoloration effect. In addition, compound 1 was used as a material for the preparation of memristors with superior properties (distinct temperature-adjusted resistive switching properties). It shows bipolar resistive switching (RS) behavior at different temperatures of 20, 50, and 100 °C. The results show that the 1-based memristor has good thermal stability, which is important for high-temperature environment applications. It also shows that crystalline viologen-POM-based compounds are ideal candidates for making memristors.

3.
Zygote ; 31(6): 557-569, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37737063

RESUMO

The aim was to explore the implications of follicular output rate (FORT), ovarian sensitivity index (OSI), ovarian response prediction index (ORPI), and follicle-to-oocyte index (FOI) in low-prognosis patients defined by POSEIDON criteria. In total, 4030 fresh in vitro fertilization (IVF) cycles from January 2013 to October 2021 were included in this retrospective cohort analysis and were categorized into four groups based on the POSEIDON criteria. The FORT between Groups 1 and 2 (0.61 ± 0.34 vs. 0.65 ± 0.35, P = 0.081) and Groups 3 and 4 (1.08 ± 0.82 vs. 1.09 ± 0.94, P = 0.899) were similar. The OSI in the order from the highest to the lowest were 3.01 ± 1.46 in Group 1, 2.28 ± 1.09 in Group 2, 1.54 ± 1.04 in Group 3, and 1.34 ± 0.96 in Group 4 (P < 0.001). The trend in the ORPI values was consistent with that in the OSI. FORT, OSI, ORPI, and FOI complemented each other and offered excellent effectiveness in reflecting ovarian reserve and response, but they were not good predictors of clinical pregnancy rate (CPR) from IVF.


Assuntos
Reserva Ovariana , Gravidez , Feminino , Humanos , Estudos Retrospectivos , Reserva Ovariana/fisiologia , Taxa de Gravidez , Fertilização in vitro , Prognóstico , Indução da Ovulação
4.
Angew Chem Int Ed Engl ; 62(4): e202217127, 2023 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-36458422

RESUMO

The bottom-up preparation of two-dimensional material micro-nano structures at scale facilitates the realisation of integrated applications in optoelectronic devices. Fibrous Phosphorus (FP), an allotrope of black phosphorus (BP), is one of the most promising candidate materials in the field of optoelectronics with its unique crystal structure and properties.[1] However, to date, there are no bottom-up micro-nano structure preparation methods for crystalline phosphorus allotropes.[1c, 2] Herein, we present the bottom-up preparation of fibrous phosphorus micropillar (FP-MP) arrays via a low-pressure gas-phase transport (LP-CVT) method that controls the directional phase transition from amorphous red phosphorus (ARP) to FP. In addition, self-powered photodetectors (PD) of FP-MP arrays with pyro-phototronic effects achieved detection beyond the band gap limit. Our results provide a new approach for bottom-up preparation of other crystalline allotropes of phosphorus.

5.
Opt Lett ; 47(21): 5659, 2022 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-37219296

RESUMO

This publisher's note contains corrections to Opt. Lett.47, 5208 (2022)10.1364/OL.473154.

6.
Opt Lett ; 47(19): 5208-5211, 2022 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-36181223

RESUMO

Internal quantum efficiency (IQE) is an important figure of merit for photoelectric applications. While the InAs core/shell (c/s) nanowire (NW) is a promising solution for efficient quantum emission, the relationship between the IQE and shell coating remains unclear. This Letter reports mid-infrared PL measurements on InAs/InGaAs, InAs/AlSb, and InAs/GaSb c/s NWs, together with bare InAs NWs as a reference. Analyses show that the IQE is depressed by a shell coating at 9 K but gets improved by up to approximately 50% for the InGaAs shell coating at 40 -140 K and up to approximately 20% beyond 110 K for the AlSb shell. The effect is ascribed not only to the crystal quality but more importantly to the radial band alignment. The result indicates the high-temperature IQE improvement of the type-I and type-II c/s NWs and the appropriateness of the mid-infrared PL analyses for narrow-gap NW evaluation.

7.
BMC Neurol ; 19(1): 30, 2019 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-30791893

RESUMO

BACKGROUND: Posterior reversible encephalopathy syndrome (PRES) is a complication that occurs during various diseases' treatment. Imaging examination is the gold standard for diagnosis. PRES frequently occurrence in patients with hematological malignancies results in poorer prognosis and higher mortality. We aim to establish a practical and operable scale for early prediction, assessment of the severity of the Posterior Reversible Encephalopathy Syndrome, and timely intervention for better prognosis. METHODS: The scale designed by reviewing the literature and by referring to clinical practice. We assessed the reliability and validity of the scale. Scale-based assessment of children undergoing chemotherapy for acute lymphoblastic leukemia conducted as early warning and intervention for those who may have PRES. RESULTS: Establishment of Posterior Reversible Encephalopathy Syndrome early warning scoring (PEWS) scale included three parts, as follows: (1) risk factors, including underlying disease, hypertension, Infection, and drug toxicity; (2) clinical features, including high cranial pressure, visual symptoms, seizure, and disturbance of consciousness; and (3) EEG features, including slow wave and epileptiform discharges. Utility assessment of PEWS scale showed that in 57 patients with acute lymphoblastic leukemia, 54 scored less than 10 and none of them detected as PRES. The other two had scores of 12 and 13 both diagnosed with PRES by brain MRI scan. CONCLUSIONS: PEWS scale can predict PRES early. PRES was highly suspected when the score was 10 points and more. Thus, prophylactic intervention can give to improve the prognosis of PRES.


Assuntos
Diagnóstico Precoce , Síndrome da Leucoencefalopatia Posterior/diagnóstico , Adolescente , Criança , Pré-Escolar , Eletroencefalografia , Feminino , Humanos , Lactente , Imageamento por Ressonância Magnética , Masculino , Reprodutibilidade dos Testes , Fatores de Risco
8.
Appl Opt ; 57(11): 2835-2840, 2018 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-29714286

RESUMO

InGaN/GaN micro-square array light-emitting diode (LED) chips (micro-chips) have been prepared via the focused ion beam (FIB) etching technique, which can not only reduce ohmic contact degradation but also control the aspect ratio precisely in three-dimensional (3D) structure LED (3D-LED) device fabrication. The effects of FIB beam current and micro-square array depth on morphologies and optical and electrical properties of the micro-chips have been studied. Our results show that sidewall surface morphology and optical and electrical properties of the micro-chips degrade with increased beam current. After potassium hydroxide etching with different times, an optimal current-voltage and luminescence performance can be obtained. Combining the results of cathodoluminescence mappings and light output-current characteristics, the light extraction efficiency of the micro-chips is reduced as FIB etch depth increases. The mechanisms of micro-square depth on light extraction have been revealed by 3D finite difference time domain.

9.
Epilepsy Behav ; 77: 13-18, 2017 12.
Artigo em Inglês | MEDLINE | ID: mdl-29073472

RESUMO

Mental retardation (MR) is one of the most common cognitive comorbidities in children with tuberous sclerosis, and there are enormous studies about its risk factors. The genetic difference and the severity of epilepsy are the two main factors, but their weight in the occurrence of MR is still unclear. Two hundred twenty-three patients with tuberous sclerosis who received intelligence assessment, genetic mutation analysis, and the epilepsy severity assessment were included in our study. Genotype-neurocognitive phenotype correlations and epilepsy-neurocognitive phenotype correlations were analyzed by binary logistic regression analysis. No statistical significant result was found on genotype-neurocognitive phenotype correlations, which contrasted the previous report. The prevalence of MR was 50.0% for the patients with tuberous sclerosis complex-1 (TSC1) mutation, 54.5% for TSC2 (p=0.561), 54.7% for patients with protein-truncating (PT) and 50.0% for patients with nontruncating (NT) (p=0.791), and 54.3% for patients with family history and 53.7% for patients without family history (p=0.748). Statistical significant results were found on epilepsy-neurocognitive phenotype correlations, both on E-chess score (p=0.01) and the occurrence of infantile spasms (p=0.014), which was consistent to the previous study. For children with tuberous sclerosis, instead of genetic factors, epilepsy may play the main role for the presence of mental retardation. Patients with mental retardation tend to have earlier seizure attack, take more AEDs, have more seizure types, and have higher seizure frequency. Among the four cognitive functions in Denver II, social ability and language ability are more vulnerable to be influenced than fine and gross motor ability.


Assuntos
Epilepsia/complicações , Deficiência Intelectual/etiologia , Inteligência/fisiologia , Convulsões/complicações , Esclerose Tuberosa/complicações , Pré-Escolar , Cognição/fisiologia , Análise Mutacional de DNA , Epilepsia/genética , Epilepsia/psicologia , Feminino , Estudos de Associação Genética , Humanos , Deficiência Intelectual/genética , Deficiência Intelectual/psicologia , Masculino , Mutação , Testes Neuropsicológicos , Fenótipo , Estudos Retrospectivos , Fatores de Risco , Convulsões/genética , Convulsões/psicologia , Habilidades Sociais , Esclerose Tuberosa/genética , Esclerose Tuberosa/psicologia
10.
Phys Chem Chem Phys ; 18(9): 6901-12, 2016 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-26879291

RESUMO

The growth and strain-compensation behaviour of InGaAs/GaAsP multi-quantum wells, which were fabricated by metal-organic chemical vapor deposition, have been studied towards the application of these quantum wells in high-power laser diodes. The effect of the height of the potential barrier on the confined level of carrier transport was studied by incorporating different levels of phosphorus content into the GaAsP barrier. The crystal quality and interface roughness of the InGaAs/GaAsP multi-quantum wells with different phosphorus contents were evaluated by high resolution X-ray diffraction and in situ optical surface reflectivity measurements during the growth. The surface morphology and roughness were characterized by atomic force microscopy, which indicates the variation law of surface roughness, terrace width and uniformity with increasing phosphorus content, owing to strain accumulation. Moreover, the defect generation and structural disorder of the multi-quantum wells were investigated by Raman spectroscopy. The optical properties of the multi-quantum wells were characterized by photoluminescence, which shows that the spectral intensity increases as the phosphorus content increases. The results suggest that more electrons are well bound in InGaAs because of the high potential barrier. Finally, the mechanism of the effect of the height of the potential barrier on laser performance was proposed on the basis of simulation calculations and experimental results.

11.
J Oral Maxillofac Surg ; 72(2): 311-21, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24438598

RESUMO

PURPOSE: To review our experience regarding the difference in management and treatment outcomes of aggressive fibromatosis of the head and neck region in children and adults, emphasizing, in particular, the role of conservative surgery in comprehensive treatment strategies. PATIENTS AND METHODS: A retrospective analysis of patients with aggressive fibromatosis was performed during a 5-year period (2008 to 2012). Nine patients were enrolled in the present study, including 5 children (age, <18 years) and 4 adults (age, >18 years). All patients underwent surgical intervention and were treated by surgical resection with different surgical margins. Adjuvant low-dose chemotherapy and radiotherapy were given to pediatric and adult patients, respectively, with macroscopically or microscopically positive surgical margins. RESULTS: All 5 pediatric patients (3 females and 2 males) received low-dose chemotherapy after conservative surgical resection (in 4 patients, microscopically incomplete resection; and in 1 patient, macroscopic residual tumor). Of the 4 adults (3 females and 1 male), 2 underwent complete surgical resection and 2 underwent surgery and postoperative radiotherapy (1 patient had microscopically suspected residual tumor and 1 had macroscopic residual tumor). The patients were followed up for a period of 7 to 51 months. Two pediatric patients and one adult patient had disease progression after resection and became stable after continued adjuvant therapy. None of the patients had functional or cosmetic defects. All patients had good long-term outcomes, with no disease progression. CONCLUSIONS: For the treatment of aggressive fibromatosis, conservative resection with preservation of form and function should be given greater priority in all age groups. Also, postoperative adjuvant therapy is vital for patients with gross or microscopic residual tumor to obtain progression-free survival.


Assuntos
Fibromatose Agressiva/cirurgia , Neoplasias de Cabeça e Pescoço/cirurgia , Adolescente , Adulto , Fatores Etários , Quimioterapia Adjuvante , Criança , Pré-Escolar , Feminino , Fibromatose Agressiva/diagnóstico por imagem , Fibromatose Agressiva/tratamento farmacológico , Fibromatose Agressiva/radioterapia , Seguimentos , Neoplasias de Cabeça e Pescoço/diagnóstico por imagem , Neoplasias de Cabeça e Pescoço/tratamento farmacológico , Neoplasias de Cabeça e Pescoço/radioterapia , Humanos , Lactente , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Neoplasia Residual/tratamento farmacológico , Neoplasia Residual/radioterapia , Cintilografia , Radioterapia Adjuvante , Estudos Retrospectivos
12.
Nanomaterials (Basel) ; 14(5)2024 Mar 03.
Artigo em Inglês | MEDLINE | ID: mdl-38470793

RESUMO

Molten slag has different properties depending on its composition. The relationship between its composition, structure, and properties has been the focus of attention in industrial manufacturing processes. This review describes the atomistic scale mechanisms by which oxides of different compositions affect the properties and structure of slag, and depicts the current state of research in the atomic simulation of molten slag. At present, the research on the macroscopic properties of molten slag mainly focuses on viscosity, free-running temperature, melting point, and desulphurization capacity. Regulating the composition has become the most direct and effective way to control slag properties. Analysis of the microevolution mechanism is the fundamental way to grasp the macroscopic properties. The microstructural evolution mechanism, especially at the atomic and nanoscale of molten slag, is reviewed from three aspects: basic oxides, acidic oxides, and amphoteric oxides. The evolution of macroscopic properties is analyzed in depth through the evolution of the atomic structure. Resolution of the macroscopic properties of molten slag by the atomic structure plays a crucial role in the development of fundamental theories of physicochemistry.

13.
ACS Nano ; 18(4): 3791-3800, 2024 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-38226921

RESUMO

The design and synthesis of efficient, inexpensive, and long-term stable heterostructured electrocatalysts with high-density dislocations for hydrogen evolution reaction in alkaline media and seawater are still a great challenge. An amorphous/crystalline/amorphous sandwiched structure with abundant dislocations were synthesized through thermal phosphidation strategies. The dislocations play an important role in the hydrogen evolution reactions. Copious dislocation defects, combined with cracks, and the synergistic interfacial effect between crystalline phase and amorphous phase regulate the electronic structure of electrocatalyst, provide more active sites, and thus endow the electrocatalysts with excellent catalytic activity under alkaline water and seawater. The overpotentials of P-NiMoO4 at 10 mA/cm2 in 1 M KOH aqueous solution and seawater are 45 and 75 mV, respectively. Additionally, the P-NiMoO4 electrocatalyst exhibits long-term stability over 100 h. This study provides a simple approach for synthesizing amorphous/crystalline/amorphous sandwiched non-noble-metal electrocatalysts with abundant dislocations for hydrogen evolution reaction.

14.
J Mater Chem B ; 12(13): 3249-3261, 2024 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-38466580

RESUMO

Over the past few decades, the critical role played by cellular contractility associated mechanotransduction in the regulation of cell functions has been revealed. In this case, numerous biomaterials have been chemically or structurally designed to manipulate cell behaviors through the regulation of cellular contractility. In particular, adhesive proteins including fibronectin, poly-L-lysine and collagen type I have been widely applied in various biomaterials to improve cell adhesion. Therefore, clarifying the effects of adhesive proteins on cellular contractility has been valuable for the development of biomaterial design. In this study, reference-free traction force microscopy with a well-organized microdot array was designed and prepared to investigate the relationship between adhesive proteins, cellular contractility, and mechanotransduction. The results showed that fibronectin and collagen type I were able to promote the assembly of focal adhesions and further enhance cellular contraction and YAP activity. In contrast, although poly-L-lysine supported cell spreading and elongation, it was inefficient at inducing cell contractility and activating YAP. Additionally, compared with cellular morphogenesis, cellular contraction was essential for YAP activation.


Assuntos
Fibronectinas , Mecanotransdução Celular , Fibronectinas/metabolismo , Mecanotransdução Celular/fisiologia , Microscopia de Força Atômica , Colágeno Tipo I , Polilisina , Tração , Adesão Celular , Materiais Biocompatíveis
15.
Clin Neuropathol ; 32(4): 324-7, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23320998

RESUMO

Epithelioid hemangioendothelioma (EHE) is a rare, locally aggressive well-differentiated endothelial tumor, which frequently develops from the peripheral veins. Meningeal EHE has only been reported in four previous cases. Here we report the case of a 38-year-old female with EHE of the meninges and secondary involvement of the skull. The patient presented with occasional headaches and slightly blurred vision. Computed tomography and magnetic resonance imaging showed a mass under the occipital bone and parietal bone, with involvement of the skull. Total resection of the tumor and involved occipital bone was performed. Histopathologically, the tumor cells had abundant eosinophilic cytoplasm and round nuclei arranged in sheets or in a nested pattern. Multiple vascular spaces containing red blood cells were observed. Intracytoplasmic vacuolization and occasional intraluminal erythrocytes were common. Immunohistochemically, the tumor cells were diffuse, intense staining for vascular markers and patchy immunoreactions for epithelial markers. Local recurrence was observed 1 month after surgery, but no regional or distant metastasis was found until 25 months. To our knowledge, this is the first case of EHE of meninges with skull involvement occurring in a female.


Assuntos
Carcinoma/diagnóstico , Diagnóstico Diferencial , Hemangioendotelioma Epitelioide/diagnóstico , Neoplasias Meníngeas/diagnóstico , Crânio/patologia , Adulto , Feminino , Humanos
16.
Materials (Basel) ; 16(17)2023 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-37687761

RESUMO

Quantum-well intermixing (QWI) technology is commonly considered as an effective methodology to tune the post-growth bandgap energy of semiconductor composites for electronic applications in diode lasers and photonic integrated devices. However, the specific influencing mechanism of the interfacial strain introduced by the dielectric-layer-modulated multiple quantum well (MQW) structures on the photoluminescence (PL) property and interfacial quality still remains unclear. Therefore, in the present study, different thicknesses of SiO2-layer samples were coated and then annealed under high temperature to introduce interfacial strain and enhance atomic interdiffusion at the barrier-well interfaces. Based on the optical and microstructural experimental test results, it was found that the SiO2 capping thickness played a positive role in driving the blueshift of the PL peak, leading to a widely tunable PL emission for post-growth MQWs. After annealing, the blueshift in the InGaAs/AlGaAs MQW structures was found to increase with increased thickness of the SiO2 layer, and the largest blueshift of 30 eV was obtained in the sample covered with a 600 nm thick SiO2 layer that was annealed at 850 °C for 180 s. Additionally, significant well-width fluctuations were observed at the MQW interface after intermixing, due to the interfacial strain introduced by the thermal mismatch between SiO2 and GaAs, which enhanced the inhomogeneous diffusion rate of interfacial atoms. Thus, it can be demonstrated that the introduction of appropriate interfacial strain in the QWI process is of great significance for the regulation of MQW band structure as well as the control of interfacial quality.

17.
J Colloid Interface Sci ; 643: 282-291, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37068362

RESUMO

To understand the underlying mechanism of the interfacial charge transfer and local chemical state variation in the nonprecious-based hydrogen evolution reaction (HER) electrocatalysts, a model system of the NiO/CeO2 heterostructure was chosen for investigation using a combination of the advanced electron microscopic characterization and first-principles calculations. The results directly proved that interfacial charge transfer occurs from Ni to Ce, leading to reduction in the valence state of Ce and increased formation of VO. This would optimize ΔGH* and facilitate the hydrogen evolution process, resulting in outstanding HER performance in 1 M KOH with a low overpotential of 99 mV at the current density of 10 mA•cm-2 and a modest Tafel slope of 78.4 mV•dec-1 for the NiO/CeO2 heterostructure sample. Therefore, the improved HER performance could be attributed to the synergistic coupling interactions and electron redistribution at the interface of NiO and CeO2. These results concretely demonstrate the direct determination of the interfacial structure of the heterostructure and provide atomistic insights to unravel the underlying mechanism of interfacial charge transfer induced HER performance improvement.

18.
Front Bioeng Biotechnol ; 10: 922159, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35711638

RESUMO

High transmembrane delivery efficiency of nanoparticles has attracted substantial interest for biomedical applications. It has been proved that the desired physicochemical properties of nanoparticles were efficient for obtaining a high cellular uptake capacity. On the other hand, biophysical stimuli from in situ microenvironment were also indicated as another essential factor in the regulation of cellular uptake capacity. Unfortunately, the influence of colony morphology on cellular uptake capacity was rarely analyzed. In this study, micropatterned PDMS stencils containing circular holes of 800/1,200 µm in diameter were applied to control colonies' size. The amino-modified nanoparticles were cocultured with micropatterned colonies to analyze the influence of colonies' morphology on the cellular uptake capacity of nanoparticles. Consequently, more endocytosed nanoparticles in larger colonies were related with a bigger dose of nanoparticles within a larger area. Additionally, the high cell density decreased the membrane-nanoparticles' contacting probability but enhanced clathrin-mediated endocytosis. With these contrary effects, the cells with medium cell density or located in the peripheral region of the micropatterned colonies showed a higher cellular uptake capacity of nanoparticles.

19.
Materials (Basel) ; 15(13)2022 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-35806700

RESUMO

As a new two-dimensional material, black arsenic phosphorus (B-AsP) has emerged as a promising electrode for lithium-ion batteries (LIBs) due to its large theoretical capacity and ability to absorb large amounts of Li atoms. However, the poor electronic conductivity and large volume expansion during the lithiation/delithiation process have largely impeded the development of B-AsP electrodes. In this study, graphene oxide (GO)/B-AsP/carbon nanotubes (CNTs) with remarkable lithium-storage property were fabricated via CVD and ultrasound-assisted method. The electrochemical behavior of the GO/B-AsP/CNTs was investigated as an anode in lithium-ion batteries. From the results, as a new-type anode for LIBs, GO/B-AsP/CNTs composite demonstrated a stable capacity of 1286 and 339 mA h g-1 at the current density of 0.1 and 1 A g-1, respectively. The capacity of GO/B-AsP/CNTs was 693 mA h g-1 after 50 cycles, resulting in capacity retention of almost 86%. In addition, the stable P-C and As-C bonds were formed between B-AsP, GO, and CNTs. Thus, volume expansion of B-AsP was alleviated and the capacity was increased due to the confining effect of GO and CNTs.

20.
J Colloid Interface Sci ; 608(Pt 3): 2192-2202, 2022 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-34785047

RESUMO

The 3D (three-dimensional) oriented nanosheet array FeNi2P electrocatalyst grown on carbon cloth (FeNi2P/CC) is explored in this work. This unique 3D oriented nanosheet array structure can expose more catalytic active sites, promote the penetration of electrolyte solution on the catalyst surface, and facilitate the transfer of ions, thus speeding up the kinetic process of Hydrogen evolution reaction (HER) and Oxygen evolution reaction (OER). At the current densities of 10 mA/cm2 in 1 M KOH solution, the HER overpotential (71 mV) of the FeNi2P/CC self-supporting electrode is very close to that of noble metal HER catalyst of 20% Pt/C (54 mV), and its OER overpotential (210 mV) is 34% lower than that of the precious metal OER catalyst of RuO2 (318 mV), demonstrating the excellent electrocatalytic performance of the FeNi2P/CC catalyst. Moreover, the cell voltage for full water splitting (at 10 mA/cm2 current densities) of the FeNi2P/CC bifunctional electrode cell is 1.52 V, which is 3.8% lower than that of the full noble-metal electrode reference cell (RuO2 || Pt/C, 1.58 V), suggesting that this FeNi2P/CC bifunctional catalyst is likely to replace precious metals to reduce the costs in full water splitting application. According to density functional theory (DFT) calculation results, the introduction of iron atom can change the electronic structure of the Ni2P, so it can reduce the adsorption energy of hydrogen and oxygen, and facilitate the adsorption and desorption of hydrogen and oxygen on the surface of the catalyst, improving its performance of HER and OER.

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