Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 16 de 16
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Angew Chem Int Ed Engl ; 63(21): e202402301, 2024 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-38482741

RESUMO

Li+ de-solvation at solid-electrolyte interphase (SEI)-electrolyte interface stands as a pivotal step that imposes limitations on the fast-charging capability and low-temperature performance of lithium-ion batteries (LIBs). Unraveling the contributions of key constituents in the SEI that facilitate Li+ de-solvation and deciphering their mechanisms, as a design principle for the interfacial structure of anode materials, is still a challenge. Herein, we conducted a systematic exploration of the influence exerted by various inorganic components (Li2CO3, LiF, Li3PO4) found in the SEI on their role in promoting the Li+ de-solvation. The findings highlight that Li3PO4-enriched SEI effectively reduces the de-solvation energy due to its ability to attenuate the Li+-solvent interaction, thereby expediting the de-solvation process. Building on this, we engineer Li3PO4 interphase on graphite (LPO-Gr) anode via a simple solid-phase coating, facilitating the Li+ de-solvation and building an inorganic-rich SEI, resulting in accelerated Li+ transport crossing the electrode interfaces and interphases. Full cells using the LPO-Gr anode can replenish its 80 % capacity in 6.5 minutes, while still retaining 70 % of the room temperature capacity even at -20 °C. Our strategy establishes connection between the de-solvation characteristics of the SEI components and the interfacial structure design of anode materials for high performance LIBs.

2.
J Am Chem Soc ; 146(7): 4752-4761, 2024 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-38334447

RESUMO

Alloy anode materials have garnered unprecedented attention for potassium storage due to their high theoretical capacity. However, the substantial structural strain associated with deep potassiation results in serious electrode fragmentation and inadequate K-alloying reactions. Effectively reconciling the trade-off between low-strain and deep-potassiation in alloy anodes poses a considerable challenge due to the larger size of K-ions compared to Li/Na-ions. In this study, we propose a chemical bonding modulation strategy through single-atom modification to address the volume expansion of alloy anodes during potassiation. Using black phosphorus (BP) as a representative and generalizing to other alloy anodes, we established a robust P-S covalent bonding network via sulfur doping. This network exhibits sustained stability across discharge-charge cycles, elevating the modulus of K-P compounds by 74%, effectively withstanding the high strain induced by the potassiation process. Additionally, the bonding modulation reduces the formation energies of potassium phosphides, facilitating a deeper potassiation of the BP anode. As a result, the modified BP anode exhibits a high reversible capacity and extended operational lifespan, coupled with a high areal capacity. This work introduces a new perspective on overcoming the trade-off between low-strain and deep-potassiation in alloy anodes for the development of high-energy and stable potassium-ion batteries.

3.
Adv Mater ; 36(13): e2308675, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38100819

RESUMO

The most successful lithium-ion batteries (LIBs) based on ethylene carbonate electrolytes and graphite anodes still suffer from severe energy and power loss at temperatures below -20 °C, which is because of high viscosity or even solidification of electrolytes, sluggish de-solvation of Li+ at the electrode surface, and slow Li+ transportation in solid electrolyte interphase (SEI). Here, a coherent lithium phosphide (Li3P) coating firmly bonding to the graphite surface to effectively address these challenges is engineered. The dense, continuous, and robust Li3P interphase with high ionic conductivity enhances Li+ transportation across the SEI. Plus, it promotes Li+ de-solvation through an electron transfer mechanism, which simultaneously accelerates the charge transport kinetics and stands against the co-intercalation of low-melting-point solvent molecules, such as propylene carbonate (PC), 1,3-dioxolane, and 1,2-dimethoxyethane. Consequently, an unprecedented combination of high-capacity retention and fast-charging ability for LIBs at low temperatures is achieved. In full-cells encompassing the Li3P-coated graphite anode and PC electrolytes, an impressive 70% of their room-temperature capacity is attained at -20 °C with a 4 C charging rate and a 65% capacity retention is achieved at -40 °C with a 0.05 C charging rate. This research pioneers a transformative trajectory in fortifying LIB performance in cryogenic environments.

4.
J Am Chem Soc ; 2023 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-37909780

RESUMO

Electrochemical Li-alloying reactions with Li-rich alloy phases render a much higher theoretical capacity that is critical for high-energy batteries, and the accompanying phase transition determines the alloying/dealloying reversibility and cycling stability. However, the influence of phase-transition characteristics upon the thermodynamic properties and diffusion kinetic mechanisms among the two categories of alloys, solid-solutions and intermetallic compounds, remains incomplete. Here we investigated three representative Li-alloys: Li-Ag alloy of extended solid-solution regions; Li-Zn alloy of an intermetallic compound with a solid-solution phase of a very narrow window in Li atom concentration; and Li-Al alloy of an intermetallic compound. Solid-solution phases undertake a much lower phase-transition energy barrier than the intermetallic compounds, leading to a considerably higher Li-alloying/dealloying reversibility and cycling stability, which is due to the subtle structural change and chemical potential gradient built up inside of the solid-solution phases. These two effects enable the Li atoms to enter the bulk of the Li-Ag alloy to form a homogeneous alloy phase. The pouch cell of the Li-rich Li20Ag alloy pairs with a LiNi0.8Co0.1Mn0.1O2 cathode under an areal capacity of 3.5 mAh cm-2 can retain 87% of its initial capacity after 250 cycles with an enhanced Coulombic efficiency of 99.8 ± 0.1%. While Li-alloying reactions and the alloy phase transitions have always been tightly linked in past studies, our findings provide important guidelines for the intelligent design of components for secondary metal batteries.

5.
Molecules ; 28(13)2023 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-37446723

RESUMO

The usage of flame retardants in flammable polymers has been an effective way to protect both lives and material goods from accidental fires. Phosphorus flame retardants have the potential to be follow-on flame retardants after halogenated variants, because of their low toxicity, high efficiency and compatibility. Recently, the emerging allotrope of phosphorus, two-dimensional black phosphorus, as a flame retardant has been developed. To further understand its performance in flame-retardant efficiency among phosphorus flame retardants, in this work, we built model materials to compare the flame-retardant performances of few-layer black phosphorus, red phosphorus nanoparticles, and triphenyl phosphate as flame-retardant additives in cellulose and polyacrylonitrile. Aside from the superior flame retardancy in polyacrylonitrile, few-layer black phosphorus in cellulose showed the superior flame-retardant efficiency in self-extinguishing, ~1.8 and ~4.4 times that of red phosphorus nanoparticles and triphenyl phosphate with similar lateral size and mass load (2.5~4.8 wt%), respectively. The char layer in cellulose coated with the few-layer black phosphorus after combustion was more continuous and smoother than that with red phosphorus nanoparticles, triphenyl phosphate and blank, and the amount of residues of cellulose coated with the few-layer black phosphorus in thermogravimetric analysis were 10 wt%, 14 wt% and 14 wt% more than that with red phosphorus nanoparticles, triphenyl phosphate and blank, respectively. In addition, although exothermic reactions, the combustion enthalpy changes in the few-layer black phosphorus (-127.1 kJ mol-1) are one third of that of red phosphorus nanoparticles (-381.3 kJ mol-1). Based on a joint thermodynamic, spectroscopic, and microscopic analysis, the superior flame retardancy of the few-layer black phosphorus was attributed to superior combustion reaction suppression from the two-dimensional structure and thermal nature of the few-layer black phosphorus.


Assuntos
Retardadores de Chama , Fósforo/química , Celulose/química , Polímeros/química
6.
Cancer Biomark ; 37(4): 261-277, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37302025

RESUMO

BACKGROUND: Cervical cancer (CC) is a malignant tumor threatening women's health. Replication factor C (RFC) 5 is significantly highly expressed in CC tissues, and the immune microenvironment plays a crucial role in tumor initiation, progression, and metastasis. OBJECTIVE: To determine the prognostic role of RFC5 in CC, analyze the immune genes significantly associated with RFC5, and establish a nomogram to evaluate the prognosis of patients with CC. METHODS: High RFC5 expression in patients with CC was analyzed and verified through TCGA GEO, TIMER2.0, and HPA databases. A risk score model was constructed using RFC5-related immune genes identified using R packages. Combining the risk score model and clinical information of patients with CC, a nomogram was constructed to evaluate the prognosis of patients with CC. RESULTS: Comprehensive analysis showed that the risk score was a prognostic factor for CC. The nomogram could predict the 3-year overall survival of patients with CC. CONCLUSIONS: RFC5 was validated as a biomarker for CC. The RFC5 related immune genes were used to establish a new prognostic model of CC.


Assuntos
Neoplasias do Colo do Útero , Humanos , Feminino , Neoplasias do Colo do Útero/genética , Prognóstico , Nomogramas , Transformação Celular Neoplásica , Bases de Dados Factuais , Microambiente Tumoral/genética , Proteína de Replicação C
7.
J Pers Med ; 13(3)2023 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-36983659

RESUMO

PURPOSE: To evaluate the degree of graft healing after "tension suspension" reconstruction of "Sherman II" anterior cruciate ligament injuries versus non-remnant preserving anatomical reconstruction and to compare the clinical outcomes of the two procedures. METHOD: The clinical data of 64 patients were retrospectively included. There were 31 cases in the "tension suspension" remnant-preserving reconstruction group and 33 cases in the non-remnant-preserving anatomical reconstruction group. The International Knee Documentation Committee (IKDC) score, the Tegner score, and the Lysholm activity score were assessed preoperatively and at 6 months, 1 year, and 2 years postoperatively, respectively. The signal/noise quotient (SNQ) of the grafts was measured at 6 months, 1 year, and 2 years after surgery to quantitatively evaluate the maturity of the grafts after ACL reconstruction; the fractional anisotropy (FA) and apparent diffusion coefficient (ADC) of the reconstructed ACL region of interest (ROI) were measured using DTI. RESULT: A total of 64 patients were included in the study. The mean SNQ values of the grafts in the 6 months, 1 year, and 2 years postoperative remnant-preserving reconstruction (RP) groups were lower than those in the non-remnant-preserving (NRP) reconstruction group, with a statistically significant difference (p < 0.05). At each postoperative follow-up, the SNQ values of the tibial and femoral sides of the RP group were lower than those of the NRP group; the SNQ values of the femoral side of the grafts in both groups were higher than those of the tibial side, and the differences were statistically significant (p < 0.05). At 6 months, 1 year, and 2 years postoperatively, the FA and ADC values of the grafts were lower in the RP group than in the NRP group, and the differences were statistically significant (p < 0.05); the IKDC score and Lysholm score of the RP group were higher than the NRP group, which was statistically significant (p < 0.05). CONCLUSION: For Sherman II ACL injury, the graft healing including ligamentization and revascularization at 2 years after the "tension suspension" remnant-preserving reconstruction was better than that of non-remnant-preserving anatomic reconstruction.

8.
ChemSusChem ; 16(14): e202300312, 2023 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-36942356

RESUMO

Due to the designable structure and capacity, organic materials are promising candidates for lithium-ion batteries. Herein, we report a novel type of porous organic frameworks (POFs) based on the coupling reaction of diazonium salt as the anodes for lithium ion storage. The active center containing an azo group and the adjacent lithium-philic adsorption site is constructed to investigate the electrochemical behaviors and reaction mechanism. As synthesized POF material (named as POF-AN) exhibits high reversible lithium storage capacities of 523 mAh g-1 at 0.5 A g-1 and 445 mAh g-1 at 2.0 A g-1 after 1500 cycles, showing excellent cycle stability and rate performance. The detailed characterizations reveal that the azo group can act as an electrochemical active site that reversibly bonds with Li-ions, and the adjacent oxygen atoms can electrostatically adsorb with Li-ions to promote the lithium storage reaction. This adsorption-assisted three-atom redox center is beneficial to synergistically enhance the adsorption and intercalation of lithium ions, which can further improve the capacity and cycle stability. By replacing the precursor, it is also facile to synthesize more similar structure types. The reversible redox chemistry of the adsorption-assisted three-atom active center provides new opportunities for the development of long lifespan and high-rate organic anodes.

9.
Front Surg ; 9: 952930, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36117844

RESUMO

Background: Compared with standard anterior cruciate ligament (ACL) reconstruction, it is controversial whether anterior cruciate ligament reconstruction (ACLR) with remnant preservation can lead to better clinical outcomes. We conducted a systematic study and meta-analysis to assess the differences in clinical efficacy between the two. Method: We searched for clinical randomized controlled studies and cohort studies included in the Cochrane library, PubMed, and Embase from March 2012 to March 2022 in English. The included studies were ACLR with or without remant preservation, and the data were extracted and the quality of the included studies was assessed by two authors, respectively. Revman 5.4 was used for statistical analysis and conclusions were presented. Result: Ten articles containing a total of 777 patients were finally included. There was no significant difference in postoperative Lachman test [OR = 1.66, 95%CI (0.79, 3.49), P = 0.18 > 0.05], Tegner score [SMD = -0.13, 95%CI (-0.47, 0.22), P = 0.46 > 0.05], synovial coverage rate by second-look arthroscopy [OR = 1.55, 95%CI (0.66, 3.65), P = 0.32 > 0.05], the rate of cyclops lesion [OR = 3.92, 95%CI (0.53, 29.29), P = 0.18 > 0.05], joint range of motion [SMD = 0.27, 95%CI (-0.13, 0.68), P = 0.19 > 0.05] and re-injury rate [OR = 0.57, 95%CI (0.18, 1.74), P = 0.32 > 0.05] between the two groups. There were statistically significant differences in postoperative Lysholm score [SMD = 0.98, 95% CI (0.32, 1.64), P = 0.004 < 0.05], International Knee Documantation Committee grade (IKDC grade) [OR = 2.19, 95%CI (1.03, 4.65), P = 0.04 < 0.05], Pivot shift test [OR = 1.71, 95%CI (1.06, 2.77), P = 0.03 < 0.05], KT1000/2000 arthrometer side-to-side difference [SMD = -0.22, 95%CI (-0.42, -0.03), P = 0.02 < 0.05], operation time [SMD = 11.69, 95%CI (8.85, 14.54), P = 0.00001 < 0.05] and degree of tibial tunnel enlargement [SMD = -0.66, 95%CI (-1.08, -0.23), P = 0.002 < 0.05]. Conclusion: This meta-analysis concluded that remnant preservation significantly had better results in terms of patient functional score (Lysholm, IKDC), knee stability (Pivot shift test, postoperative side-to-side anterior laxity) and tibial tunnel enlargement. In terms of complications (incidence of Cyclops lesions, range of motion, re-injury rate), no significant differences were seen between the two groups. Although many studies concluded that remnant preservation could bring better synovial coverage, this meta-analysis indicated that there is insufficient evidence to support it, possibly due to different remnant preservation procedures.The potential risks associated with longer operation times are also worth considering.

10.
Cancer Inform ; 21: 11769351221090921, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35464777

RESUMO

Mounting evidence suggests that the tumor microenvironment plays an important role in the occurrence and development of cancer, with immune system dysfunction being closely related to malignant cancers. We aimed to screen immune-related genes (IRGs) to generate an IRG pair (IRGP)-based prognostic signature for cervical cancer (CC). Datasets were obtained from The Cancer Genome Atlas and Gene Expression Omnibus databases and used as training and validation cohorts, respectively. Using the ImmPort database, IRGs in control and CC samples were compared, and differentially expressed genes were identified to construct an IRGP prognostic signature. Based on this analysis, 25 IRGPs were identified as important factors for the prognosis of CC. Univariate and multivariate Cox regression analyses further showed that the IRGP signature was an independent prognostic factor of overall survival. In summary, we successfully constructed an IRGP prognostic signature of CC, providing insights into immunotherapy for CC.

11.
RSC Adv ; 12(13): 8160-8171, 2022 Mar 08.
Artigo em Inglês | MEDLINE | ID: mdl-35424738

RESUMO

Tetracycline (TC) is a broad-spectrum antibiotic. When humans consume too much food containing tetracycline residues, it can be a serious health hazard. Therefore, it is essential to develop a strategy to detect TC. In this study, we prepared light blue-green luminescent nitrogen-doped graphene quantum dots (N-GQDs) by a hydrothermal method using the natural products potato straight-chain starch and urea as precursors; the fluorescence quantum yield of the prepared N-GQDs was 5.2%. We investigated the detection of tetracycline (TC) by this N-GQD fluorescent sensor based on the internal filtration effect (IFE) of TC on N-GQDs. The reaction is green, simple and no other contaminating products are present. A good linear relationship was established between the relative fluorescence intensity ratio of the system and the logarithm of the TC concentration of 2.5 × 10-10 to 5 × 10-6 M (R 2 = 0.9930), with a detection limit of 9.735 × 10-13 M. The method has been used to analyze TC in three real food samples (whole milk, skim milk, honey) with low detection limits (3.750 × 10-11 to 2.075 × 10-9 M), wide linear range, and satisfactory recoveries of 93.80-109.20% were obtained. In conclusion, the proposed method is a green, rapid, highly sensitive and selective method for the detection of tetracycline in real food samples, demonstrating the potential application of N-GQDs in food detection.

12.
Nanomaterials (Basel) ; 12(4)2022 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-35215019

RESUMO

The use of clenbuterol (CLB) in large quantities in feedstuffs worldwide is illegal and potentially dangerous for human health. In this study, we directly prepared nitrogen-doped graphene quantum dots (N-GQDs) by a one-step method using cationic-etherified starch as raw material without pollution, which has the advantages of simple, green, and rapid synthesis of N-GQDs and high doping efficiency of nitrogen elements, compared with the traditional nitrogen doping method of reacting nitrogen source raw material with quantum dots. The N-GQDs synthesized by cationic etherification starch with different substitution degrees (DSs) exhibit good blue-green photoluminescence, good fluorescence stability, and water solubility. By comparing the fluorescence emission intensity of the two methods, the N-GQDs prepared by this method have higher fluorescence emission intensity and good fluorescence stability. Based on the static quenching mechanism between CLB and N-GQDs, a fluorescent probe was designed to detect CLB, which exhibited a wide linear range in the concentration range of 5 × 10-10~5 × 10-7 M (R2 = 0.9879) with a limit of detection (LOD) of 2.083 × 10-13 M. More excitingly, the N-GQDs fluorescent probe exhibited a satisfactory high selectivity. Meanwhile, it can be used for the detection of CLB in chicken and beef, and good recoveries were obtained. In summary, the strategic approach in this paper has potential applications in the detection of risky substances in the field of food safety.

13.
Mol Med Rep ; 25(3)2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-35088882

RESUMO

Osteoarthritis (OA), one of the most common joint diseases, is characterized by fibrosis, rhagadia, ulcers and attrition of articular cartilage due to a number of factors. The etiology of OA remains unclear, but its occurrence has been associated with age, obesity, inflammation, trauma and genetic factors. Inflammatory cytokines are crucial for the occurrence and progression of OA. The intra­articular proinflammatory and anti­inflammatory cytokines jointly maintain a dynamic balance, in accordance with the physiological metabolism of articular cartilage. However, dynamic imbalance between proinflammatory and anti­inflammatory cytokines can cause abnormal metabolism in knee articular cartilage, which leads to deformation, loss and abnormal regeneration, and ultimately destroys the normal structure of the knee joint. The ability of articular cartilage to self­repair once damaged is limited, due to its inability to obtain nutrients from blood vessels, nerves and lymphatic vessels, as well as limitations in the extracellular matrix. There are several disadvantages inherent to conventional repair methods, while cartilage tissue engineering (CTE), which combines proinflammatory and anti­-inflammatory cytokines, offers a new therapeutic approach for OA. The aim of the present review was to examine the proinflammatory factors implicated in OA, including IL­1ß, TNF­α, IL­6, IL­15, IL­17 and IL­18, as well as the key anti­inflammatory factors reducing OA­related articular damage, including IL­4, insulin­like growth factor and TGF­ß. The predominance of proinflammatory over anti­inflammatory cytokine effects ultimately leads to the development of OA. CTE, which employs mesenchymal stem cells and scaffolding technology, may prevent OA by maintaining the homeostasis of pro­ and anti­inflammatory factors.


Assuntos
Cartilagem Articular , Osteoartrite , Anti-Inflamatórios/uso terapêutico , Cartilagem Articular/metabolismo , Condrócitos/metabolismo , Citocinas/metabolismo , Humanos , Osteoartrite/tratamento farmacológico , Osteoartrite/terapia , Engenharia Tecidual
14.
Orthop Surg ; 13(6): 1828-1834, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34664415

RESUMO

OBJECTIVE: To investigate the clinical and radiographic short-term results of arthroscopic treatment for posterior labrum tears with an attached bony fragment after traumatic posterior hip dislocation. METHODS: Between July 2014 and May 2019, a consecutive series of nine patients diagnosed with a posterior labrum tear with an attached bony fragment after traumatic posterior hip dislocation were treated by hip arthroscopic techniques. The patients had been injured in traffic accidents (n = 6) or high falls (n = 3). All patients were provided primary treatment at the emergency department of our institution, and then were transferred to our department for arthroscopy. Demographic data (e.g. gender, age, etc), intraoperative findings, the preoperative and postoperative multiple clinical scores and radiological results were subsequently assessed. Visual analogue scale for pain (VAS) and modified Harris hip scores (mHHSs) were measured and compared before surgery, and at the last follow-up. RESULTS: A total of nine patients were enrolled, all of them were male, with a mean age at surgery of 32.2 ± 5.6 years (range, 22-65 years). The patients were followed-up for an average of 26.5 ± 4.1 (range, 24 to 50 years). During the arthroscopic surgery, all patients had labral tears with posterior acetabular rim fracture. All patients had loose osteochondral fragments. Five had partial or complete tears of ligamentum teres. Two patients had osteochondral damage. Two had capsular rupture. Postoperative X-ray films and three dimension computed tomography (3D-CT) showed satisfactory reduction of posterior acetabular wall fractures. The mHHS before surgery and at 1 year and 2 years after surgery were 51.8 ± 4.3, 81.8 ± 2.0 and 87.5 ± 1.9 respectively; VAS scores were 5.6 ± 0.5, 1.3 ± 0.3 and 0.7 ± 0.3 respectively. As compared with the condition before surgery, there was a significant improvement in the mHHS and VAS scores at 1 year and 2 years after surgery (P < 0.01). There was no significant improvement in the mHHS and VAS scores between 1 year and 2 years after surgery (P < 0.05). At the final follow-up, all patients had regained full range of motion (ROM) and were satisfied with the results. None of the patients showed signs of heterotopic ossification, avascular necrosis or progression of osteoarthritis of the hip joint. CONCLUSION: Traumatic dislocation is accompanied by a variety of intra-articular hip joint pathologies. Managing posterior acetabular rim fracture after traumatic posterior hip dislocation using arthroscopic reduction and fixation with anchors is a safe and minimally invasive option and delays the progression of traumatic osteoarthritis.


Assuntos
Acetábulo/lesões , Acetábulo/cirurgia , Artroscopia/métodos , Fixação Interna de Fraturas/métodos , Fraturas Ósseas/cirurgia , Luxação do Quadril/cirurgia , Adulto , Idoso , Humanos , Masculino , Pessoa de Meia-Idade , Medição da Dor , Medidas de Resultados Relatados pelo Paciente , Adulto Jovem
15.
Science ; 370(6513): 192-197, 2020 10 09.
Artigo em Inglês | MEDLINE | ID: mdl-33033214

RESUMO

High-rate lithium (Li) ion batteries that can be charged in minutes and store enough energy for a 350-mile driving range are highly desired for all-electric vehicles. A high charging rate usually leads to sacrifices in capacity and cycling stability. We report use of black phosphorus (BP) as the active anode for high-rate, high-capacity Li storage. The formation of covalent bonds with graphitic carbon restrains edge reconstruction in layered BP particles to ensure open edges for fast Li+ entry; the coating of the covalently bonded BP-graphite particles with electrolyte-swollen polyaniline yields a stable solid-electrolyte interphase and inhibits the continuous growth of poorly conducting Li fluorides and carbonates to ensure efficient Li+ transport. The resultant composite anode demonstrates an excellent combination of capacity, rate, and cycling endurance.

16.
J Am Chem Soc ; 140(24): 7561-7567, 2018 06 20.
Artigo em Inglês | MEDLINE | ID: mdl-29575904

RESUMO

Exfoliated black phosphorus (BP), as a monolayer or few-layer material, has attracted tremendous attention owing to its unique physical properties for applications ranging from optoelectronics to photocatalytic hydrogen production. Approaching intrinsic properties has been, however, challenged by chemical reactions and structure degradation of BP under ambient conditions. Surface passivation by capping agents has been proposed to extend the processing time window, yet contamination or structure damage rise challenges for BP applications. Here, we report experiments combined with first-principle calculations that address the degradation chemistry of BP. Our results show that BP reacts with oxygen in water even without light illumination. The reaction follows a pseudo-first-order parallel reaction kinetics, produces PO23-, PO33-, and PO43- with reaction rate constants of 0.019, 0.034, and 0.023 per day, respectively, and occurs preferentially from the P atoms locating at BP edges, which yields structural decay from the nanoflake edges in water. In addition, a negligible decay ratio (0.9 ± 0.3 mol %) and preserved photocatalytic activity of BP are observed after storage in deoxygenated water for 15 days without surface passivation under ambient light. Our results reveal the chemistry of BP degradation and provide a practical approach for exfoliation, delivery, and application of BP.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...