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Metal-support interaction engineering is considered an efficient strategy for optimizing the catalytic activity. Nevertheless, the fine regulation of metal-support interactions as well as understanding the corresponding catalytic mechanisms (particularly those of non-carbon support-based counterparts) remains challenging. Herein, a controllable adsorption-impregnation strategy was proposed for the preparation of a porous nonlayered 2D NiO nanoflake support anchored with different forms of Pt nanoarchitectures, i.e. single atoms, clusters and nanoparticles. Benefiting from the unique porous architecture of NiO nanosheets, abundant active defect sites facilitated the immobilization of Pt single atoms onto the NiO crystal, resulting in NiO lattice distortion and thus changing the valence state of Pt, chemical bonding, and the coordination environment of the metal center. The synergy of the porous NiO support and the unexpected Pt single atom-NiO interactions effectively accelerated mass transfer and reduced the reaction kinetic barriers, contributing to a significantly enhanced mass activity of 5.59 A mgPt -1 at an overpotential of 0.274 V toward the electrocatalytic oxygen evolution reaction (OER) while 0.42 A mgPt -1 at a potential of 0.7 V vs. RHE for the methanol oxidation reaction (MOR) in an alkaline system, respectively. This work may offer fundamental guidance for developing metal-loaded/dispersed support nanomaterials toward electrocatalysis through the fine regulation of metal-support interactions.
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While nanostructural engineering holds promise for improving the stability of high-capacity silicon (Si) anodes in lithium-ion batteries (LIBs), challenges like complex synthesis and the high cost of nano-Si impede its commercial application. In this study, we present a local reduction technique to synthesize micron-scale monolithic layered Si (10-20 µm) with a high tap density of 0.9-1.0 g cm-3 from cost-effective montmorillonite, a natural layered silicate mineral. The created mesoporous structure within each layer, combined with the void spaces between interlayers, effectively mitigates both lateral and vertical expansion throughout repeated lithiation/delithiation cycles. Furthermore, the remaining SiO2 network fortifies the layered structure, preventing it from collapsing during cycling. Half-cell tests reveal a capacity retention of 92% with a reversible capacity of 1130 mAh g-1 over 500 cycles. Moreover, the pouch cell integrated with this Si anode (with a mass loading of 3.0 mg cm-2) and a commercial NCM811 cathode delivers a high energy density of 655 Wh kg-1 (based on the total mass of the cathode and anode) and maintains 82% capacity after 200 cycles. This work demonstrates a cost-efficient and scalable strategy to manufacture high-performance micron Si anodes for the ever-growing demand for high-energy LIBs.
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INTRODUCTION: Hematology is an essential field for investigating the prognostic outcomes of cardiovascular diseases (CVDs). Recent research has suggested that mean corpuscular hemoglobin concentration (MCHC) is associated with a poor prognosis in several CVDs. There is no evidence of a correlation between MCHC and hypertension. Therefore, our study aimed to analyze the association of MCHC with all-cause and cardiovascular mortality in hypertensive patients. METHODS: We used cohort data from U.S. adults who participated in the National Health and Nutrition Examination Survey from 1999-2014. COX regression was applied to analyze the relationship between MCHC and all-cause and cardiovascular mortality. In addition, three models were adjusted to reduce confounding factors. We reanalyzed the data after propensity score matching (PSM) to inspect the stability of the results. Stratified analysis was additionally adopted to investigate the results of each subgroup. RESULTS: Our research included 15,154 individuals. During a mean follow-up period of 129 months, 30.6% of the hypertensive population succumbed to mortality. Based on previous studies, we categorized patients with MCHC ≤33mg/dl as the hypochromia group and those with >33mg/dl as the non-hypochromia group. After PSM, the hypochromia group had higher all-cause mortality (adjusted hazard ratio [HR]:1.26, 95% confidence interval [95%CI]:1.11-1.43) and cardiovascular mortality (adjusted HR:1.42, 95%CI:1.12-1.80) than the non-hypochromia group. The results of the COX regression remain stable after matching. Stratified analyses before PSM revealed an interaction of anemia in the relationship between MCHC and mortality, whereas there was no significant interaction after matching. CONCLUSION: In hypertensive individuals, low MCHC was correlated with a poor prognosis. Further studies on MCHC are necessary to analyze the potential mechanisms of its poor prognosis in hypertensive populations.
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Índices de Eritrócitos , Hemoglobinas , Hipertensão , Humanos , Hipertensão/sangue , Hipertensão/mortalidade , Masculino , Feminino , Pessoa de Meia-Idade , Estudos de Coortes , Adulto , Hemoglobinas/análise , Hemoglobinas/metabolismo , Idoso , Doenças Cardiovasculares/mortalidade , Doenças Cardiovasculares/sangue , Prognóstico , Inquéritos Nutricionais , Modelos de Riscos ProporcionaisRESUMO
Most nonoxide catalysts based on transition metal elements will inevitably change their primitive phases under anodic oxidation conditions in alkaline media. Establishing a relationship between the bulk phase and surface evolution is imperative to reveal the intrinsic catalytic active sites. In this work, it is demonstrated that the introduction of Fe facilitates the phase transition of orthorhombic CoSe2 into its cubic counterpart and then accelerates the Co-Fe hydroxide layer generation on the surface during electrocatalytic oxygen evolution reaction (OER). As a result, the Fe-doped cubic CoSe2 catalyst exhibits a significantly enhanced activity with a considerable overpotential decrease of 79.9 and 66.9 mV to deliver 10 mA·cm-2 accompanied by a Tafel slope of 48.0 mV·dec-1 toward OER when compared to orthorhombic CoSe2 and Fe-doped orthorhombic CoSe2, respectively. Density functional theory (DFT) calculations reveal that the introduction of Fe on the surface hydroxide layers will tune electron density around Co atoms and raise the d-band center. These findings will provide deep insights into the surface reconstitution of the OER electrocatalysts based on transition metal elements.
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Moth insects rely on sex pheromones for long distance attraction and searching for sex partners. The biosynthesis of moth sex pheromones involves the catalytic action of multiple enzymes, with desaturases playing a crucial role in the process of carbon chain desaturation. However, the specific desaturases involved in sex pheromone biosynthesis in fall armyworm (FAW), Spodoptera frugiperda, have not been clarified. In this study, a Δ11 desaturase (SfruDES1) gene in FAW was knocked out using the CRISPR/Cas9 genome editing system. A homozygous mutant of SfruDES1 was obtained through genetic crosses. The gas chromatography-mass spectrometry (GC-MS) analysis results showed that the three main sex pheromone components (Z7-12:Ac, Z9-14:Ac, and Z11-16:Ac) and the three minor components (Z9-14:Ald, E11-14:Ac and Z11-14:Ac) of FAW were not detected in homozygous mutant females compared to the wild type. Furthermore, behavioral assay demonstrated that the loss of SfruDES1 resulted in a significant reduction in the attractiveness of females to males, along with disruptions in mating behavior and oviposition. Additionally, in a heterologous expression system, recombinant SfruDES1 could introduce a cis double bond at the Δ11 position in palmitic acid, which resulted in the changes in components of the synthesized products. These findings suggest desaturase plays a key role in the biosynthesis of sex pheromones, and knockout of the SfruDES1 disrupts sex pheromone biosynthesis and mating behavior in FAW. The SfruDES1 could serve as tool to develop a control method for S. frugiperda.
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Mariposas , Atrativos Sexuais , Animais , Feminino , Masculino , Spodoptera/genética , Spodoptera/metabolismo , Atrativos Sexuais/metabolismo , Oviposição , Mariposas/genética , Ácidos Graxos Dessaturases/genética , Ácidos Graxos Dessaturases/química , Ácidos Graxos Dessaturases/metabolismoRESUMO
Background: It is recognized that patients' blood glucose fluctuates over time during acute disease episodes, especially during the outbreak of cardiovascular events, regardless of the presence of an abnormal blood glucose profile prior to admission to the hospital. Glucose fluctuations in patients with acute myocardial infarction (AMI) in the intensive care unit (ICU) are currently not adequately monitored and studied. We focused on blood glucose fluctuation values within 24â h of admission to assess their association with 30-day and 1-year mortality. Methods: Data of patients with AMI aged 18 years or older from the Critical Care Medical Information Marketplace database III V1.4 were available for analysis in this research. Glucose data were obtained by measurement. A total of 390 of them were treated with PCI. The principal consequence was 30-day and 1-year mortality in patients with AMI. The effect of different glucose fluctuations within 24â h of admission on mortality was predicted by constructing a multivariate Cox regression model with four model adjustments and Kaplan-Meier survival curves. Additionally, we performed curve-fitting analyses to show the correlation between blood glucose fluctuations and risk of death. Results: We selected 1,699 AMI patients into our study through screening. The included population was categorized into three groups based on the tertiles of blood glucose fluctuation values within 24â h of admission to the ICU. The three groups were <25â mg/dl, 25-88â mg/dl and >88â mg/dl. By cox regression analysis, the group with the highest blood glucose fluctuation values (>88â mg/dl) had the most significant increase in 30-day and 1-year mortality after excluding confounding factors (30-day mortality adjusted HR = 2.11; 95% CI = 1.49-2.98 p < 0.001; 1-year mortality adjusted HR = 1.83; 95% CI = 1.40-2.39 p < 0.001). As demonstrated by the Kaplan-Meier survival curves, the group with the greatest fluctuations in blood glucose has the worst 30-day and 1-year prognosis. Conclusions: The extent of glucose fluctuations in patients with AMI in the first 24â h after ICU admission is an essential predictor as to 30-day as well as 1-year mortality. When blood glucose fluctuates more than 88â mg/dl within 24â h, mortality increases significantly with the range of blood glucose fluctuations.
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Rational carbonate electrolyte chemistry is critical for the development of high-voltage lithium metal batteries (LMBs). However, the implementation of traditional carbonate electrolyte is greatly hindered by the generation of an unstable electrode interphase and corrosive by-product (HF). Herein, we propose a triple-function eutectic solvent additive of N-methylacetamide (NmAc) with LiNO3 to enhance the stability and compatibility of carbonate electrolyte. Firstly, the addition of NmAc significantly improves the solubility of LiNO3 in carbonate electrolyte by forming an eutectic pair, which regulates the Li+ solvation structure and leads to dense and homogenous Li plating. Secondly, the hydrolysis of acidic PF5 is effectively alleviated due to the strong complexation of NmAc with PF5, thus reducing the generation of corrosive HF. In addition, the optimized cathode electrolyte interphase layer decreases the structural degradation and transition metal dissolution. Consequently, Li||LiNi0.6Co0.2Mn0.2O2 (NCM622) cells with the designed electrolyte deliver superior long-term cycle reversibility and excellent rate capability. This study unveils the rationale for incorporating eutectic solvent additives within carbonate electrolytes, which significantly contribute to the advancement of their practical application for high-voltage LMBs.
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The widespread presence of formaldehyde (HCHO) pollutant has aroused significant environmental and health concerns. The catalytic oxidation of HCHO into CO2 and H2O at ambient temperature is regarded as one of the most efficacious and environmentally friendly approaches; to achieve this, however, accelerating the intermediate formate species formation and decomposition remains an ongoing obstacle. Herein, a unique tandem catalytic system with outstanding performance in low-temperature HCHO oxidation is proposed on well-structured Pd/Mn3O4-MnO catalysts possessing bifunctional catalytic centers. Notably, the optimized tandem catalyst achieves complete oxidation of 100 ppm of HCHO at just 18 °C, much better than the Pd/Mn3O4 (30%) and Pd/MnO (27%) counterparts as well as other physical tandem catalysts. The operando analyses and physical tandem investigations reveal that HCHO is primarily activated to gaseous HCOOH on the surface of Pd/Mn3O4 and subsequently converted to H2CO3 on the Pd/MnO component for deep decomposition. Theoretical studies disclose that Pd/Mn3O4 exhibits a favorable reaction energy barrier for the HCHO â HCOOH step compared to Pd/MnO; while conversely, the HCOOH â H2CO3 step is more facilely accomplished over Pd/MnO. Furthermore, the nanoscale intimacy between two components enhances the mobility of lattice oxygen, thereby facilitating interfacial reconstruction and promoting interaction between active sites of Pd/Mn3O4 and Pd/MnO in local vicinity, which further benefits sustained HCHO tandem catalytic oxidation. The tandem catalysis demonstrated in this work provides a generalizable platform for the future design of well-defined functional catalysts for oxidation reactions.
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Formaldeído , Paládio , Temperatura , Domínio Catalítico , Oxirredução , Catálise , Paládio/químicaRESUMO
Electrochemical NO3- reduction reaction (NO3RR) is a promising technique for green NH3 synthesis. Tungsten oxide (WO3) has been regarded as an effective electrocatalyst for electrochemical NH3 synthesis. However, the weak adsorption and the sluggish hydrogenation of oxynitride intermediates (NOx, e.g., *NO3 and *NO2) over WO3 materials hinder the efficiency of converting NO3- to NH3. Herein, we design a heterostructure of tungsten nitride (WN) and WO3 (WN/WO3) nanosheets to optimize *NO3 and *NO2 adsorptions and facilitate *NO2 hydrogenations to achieve a highly efficient electrochemical NO3RR to produce NH3. Theoretical calculations predict that locally introducing WN into WO3 will shorten the distance between adjacent W atoms, resulting in *NO3 and *NO2 being strongly adsorbed on W active sites in the form of bidentate ligands instead of the relatively weak monodentate ligands. Furthermore, WN facilitates H2O dissociation to supply the requisite protons, which is beneficial for *NO2 hydrogenations. Inspired by theoretical prediction, WN/WO3 nanosheets are successfully fabricated through a high-temperature nitridation process. The transmission electron microscopy, X-ray photoelectron spectroscopy, and X-ray absorption near-edge spectroscopy investigations confirm that the amorphous WN has been locally introduced in situ into WO3 nanosheets to form a composite heterostructure. The as-prepared WN/WO3 nanosheets exhibit a high Faraday efficiency of 88.9 ± 7.2% and an appreciable yield rate of 8.4 mg h-1 cm-2 toward NH3 production, which is much higher than that of individual WO3 and WN. The enhanced adsorption and hydrogenation behaviors of *NOx over WN/WO3 are characterized by in situ Fourier-transform infrared spectroscopy, consistent with the theoretical predictions. This work develops facile and effective heterostructure nanomaterials to tune the adsorption and hydrogenation of NOx for boosting the efficiency from NO3- to NH3.
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Layered gadolinium hydroxide (LGdH) and Ti3C2 monolayers were assembled into a LGdH/Ti3C2 (GTC) hybrid. The hybrid demonstrated enhanced near-infrared (NIR) light absorption properties and superior photothermal performance. Moreover, the GTC hybrid achieved an excellent T1-weighted magnetic resonance imaging (MRI) effect.
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Cerebrospinal fluid contacting neurons (CSF-cNs) are a specific type of neurons located around the ventricles in the brain and the central canal in the spinal cord and have been demonstrated to be intrinsic sensory neurons in the central nervous system. One of the important channels responsible for the sensory function is the polycystic kidney disease 2-like 1 (PKD2L1) channel. Most of the studies concerning the distribution and function of the PKD2L1-expressing CSF-cNs in the spinal cord have previously been performed in non-mammalian vertebrates. In the present study immunohistochemistry was performed to determine the distribution of PKD2L1-immunoreactive (IR) CSF-cNs in the spinal cords of four mammalian species: mouse, rat, cat, and macaque monkey. Here, we found that PKD2L1-expressing CSF-cNs were present at all levels of the spinal cord in these animal species. Although the distribution pattern was similar across these species, differences existed. Mice and rats presented a clear PKD2L1-IR cell body labeling, whereas in cats and macaques the PKD2L1-IR cell bodies were more weakly labeled. Ectopic PKD2L1-IR neurons away from the ependymal layer were observed in all the animal species although the abundance and the detailed locations varied. The apical dendritic protrusions with ciliated fibers were clearly seen in the lumen of the central canal in all the animal species, but the sizes of protrusion bulbs were different among the species. PKD2L1-IR cell bodies/dendrites were co-expressed with doublecortin, MAP2 (microtubule-associated protein 2), and aromatic L-amino acid decarboxylase, but not with NeuN (neuronal nuclear protein), indicating their immature properties and ability to synthesize monoamine transmitters. In addition, in situ hybridization performed in rats revealed PKD2L1 mRNA expression in the cells around the central canal. Our results indicate that the intrinsic sensory neurons are conserved across non-mammalian and mammalian vertebrates. The similar morphology of the dendritic bulbs with ciliated fibers (probably representing stereocilia and kinocilia) protruding into the central canal across different animal species supports the notion that PKD2L1 is a chemo- and mechanical sensory channel that responds to mechanical stimulations and maintains homeostasis of the spinal cord. However, the differences of PKD2L1 distribution and expression between the species suggest that PKD2L1-expressing neurons may receive and process sensory signals differently in different animal species.
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Roedores , Medula Espinal , Animais , Gatos , Camundongos , Ratos , Sistema Nervoso Central , Neurônios , PrimatasRESUMO
Jasmonic acid (JA) and methyl jasmonate (MeJA), the crucial plant hormones, can induce the emission of plant volatiles and regulate the behavioral responses of insect pests or their natural enemies. In this study, two jasmonic acid carboxyl methyltransferases (JMTs), GhJMT1 and GhJMT2, involved in MeJA biosynthesis in Gossypium. hirsutum were identified and further functionally confirmed. In vitro, recombinant GhJMT1 and GhJMT2 were both responsible for the conversion of JA to MeJA. Quantitative real-time PCR (qPCR) measurement indicated that GhJMT1 and GhJMT2 were obviously up-regulated in leaves and stems of G. hirsutum after being treated with MeJA. In gas chromatography-mass spectrometry (GC-MS) analysis, MeJA treatment significantly induced plant volatiles emission such as (E)-ß-ocimene, (Z)-3-hexenyl acetate, linalool and (3E)-4,8-dimethyl-1,3,7-nonatriene (DMNT), which play vital roles in direct and indirect plant defenses. Moreover, antennae of parasitoid wasps Microplitis mediator showed electrophysiological responses to MeJA, ß-ocimene, (Z)-3-hexenyl acetate and linalool at a dose dependent manner, while our previous research revealed that DMNT excites electrophysiological responses and behavioral tendencies. These findings provide a better understanding of MeJA biosynthesis and defense regulation in upland cotton, which lay a foundation to JA and MeJA employment in agricultural pest control.
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Herein, we report the study of atomically precise AuxAg25-x nanoclusters (NCs) toward photocatalytic hydrogen evolution. The incorporation of Au atoms into Ag25 NCs not only narrowed the HOMO-LUMO gaps but also created an interstitial Au-Ag microenvironment, which promoted the photogenerated charge carrier utilization and optimized the reaction dynamics.
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Olfaction plays a crucial role in locating food sources, mates, and spawning sites in the fall armyworm (FAW), Spodoptera frugiperda (Lepidoptera: Noctuidae). In the current study, SfruOR14, a highly conserved odorant receptor (OR) in lepidopteran species, was newly uncovered in S. frugiperda. In two-electrode voltage clamp recordings, the SfruOR14/Orco complex was narrowly tuned to six volatile compounds including phenylacetaldehyde (PAA), benzaldehyde, heptaldehyde, (E)-2-hexen-1-al, cinnamaldehyde, and 2-phenylethanol, among which PAA showed the strongest binding affinity. Subsequent homology modeling and molecular docking revealed that Phe79, His83, Tyr149, Pro176, Gln177, Leu202, and Thr348 in SfruOR14 were the key binding residues against the six ligands. Finally, as a result of site-directed mutagenesis, the SfruOR14His83Ala mutant completely lost its binding capabilities toward all ligands. Taken together, our findings provide valuable insights into understanding the interaction between SfruOR14 and the chemical ligands including PAA, which can help to design novel olfactory modulators for pest control.
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Mutação Puntual , Receptores Odorantes , Animais , Spodoptera , Ligantes , Simulação de Acoplamento MolecularRESUMO
Recently, atomically precise metal nanoclusters (NCs) become a new class of photosensitizer for light energy conversion in metal-cluster-sensitized semiconductor (MCSS) system. However, fundamental understanding for the suitable combination of NCs and semiconductor is still unclear. Aside from aspects of light harvesting, energy level alignment and catalytic activity, interfacial interaction behavior at NCs/semiconductor interface is also crucial due to its important influence in charge transportation. In this work, the interface interaction between Au NCs and TiO2 is examined by precise transformation of Au NCs from Au22(SG)18 to Au18(SG)14, as well as its effect on photocatalytic hydrogen production activity. From the optical, charge transport and solid-states spectroscopy analyses, it is able to display that precisely tuning the number of core atoms from Au22(SG)18 to Au18(SG)14 results in the strong interface interaction between Au NCs and TiO2, reflecting in high difference of work function and modified surface band bending of TiO2, therefore promoting the injection of electrons from NCs to TiO2 and reducing interfacial charges recombination. As a result, Au18(SG)14/TiO2 shows higher hydrogen generation rate than Au22(SG)18/TiO2 under light irradiation. This work would provide new insights into rational combination of metal NCs with semiconductor and highlights the overlooked effect of interfacial interaction behavior on light energy conversion.
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The high specific capacity and relatively low volume expansion of silicon suboxide (SiOx) highlight its potential as one of the most promising anode materials for lithium-ion batteries. Nevertheless, the traditional binder of polyacrylic acid (PAA) still cannot adapt to enormous stress during the repeated volume expansion/contraction owing to its intrinsic rigid backbone. Inspired by the "soft and hard composite body armor", we herein design a double-wrapped binder consisting of PAA with a high internal Young's modulus (hard part) and polyurethane (DOU) with a low external Young's modulus (soft part). When the SiOx particle expands during lithiation, the rigid PAA firstly accommodates the volume change to dissipate most of the inner stress, and the elastic DOU with triple dynamic bonds serves as a buffer layer to absorb the residual stress via the breakage/formation of dynamic bonds. By optimizing the PAA/DOU ratio, the SiOx anode can maintain the integrity during long-term cycling and deliver a relatively high reversible capacity of 1064.1 mAh g-1 with a preeminent capacity retention of 83.7% at 0.5C after 300 cycles. Such a double-wrapped binder can provide a novel design strategy for multicomponent functional polymer binders toward high-performance SiOx anodes.
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Chemotherapy is a common strategy to treat cancer. However, acquired resistance and metastasis are the major obstacles to successful treatment. Anastasis is a process by which cells survive executioner caspase activation when facing apoptotic stress. Here we demonstrate that colorectal cancer cells can undergo anastasis after transient exposure to chemotherapeutic drugs. Using a lineage tracing system to label and isolate cells that have experienced executioner caspase activation in response to drug treatment, we show that anastasis grants colorectal cancer cells enhanced migration, metastasis, and chemoresistance. Mechanistically, treatment with chemotherapeutic drugs induces upregulated expression of cIAP2 and activation of NFκB, which are required for cells to survive executioner caspase activation. The elevated cIAP2/NFκB signaling persists in anastatic cancer cells to promote migration and chemoresistance. Our study unveils that cIAP2/NFκB-dependent anastasis promotes acquired resistance and metastasis after chemotherapy.
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Reversão da Morte Celular , Neoplasias Colorretais , Humanos , Resistencia a Medicamentos Antineoplásicos , NF-kappa B , Neoplasias Colorretais/tratamento farmacológico , Neoplasias Colorretais/genética , CaspasesRESUMO
Cancer relapse and metastasis are major obstacles for effective treatment. One important mechanism to eliminate cancer cells is to induce apoptosis. Activation of executioner caspases is the key step in apoptosis and was considered "a point of no return". However, in recent years, accumulating evidence has demonstrated that cells can survive executioner caspase activation in response to apoptotic stimuli through a process named anastasis. Here we show that breast cancer cells that have survived through anastasis (anastatic cells) after exposure to chemotherapeutic drugs acquire enhanced proliferation and migration. Mechanistically, cadherin 12 (CDH12) is persistently upregulated in anastatic cells and promotes breast cancer malignancy via activation of ERK and CREB. Moreover, we demonstrate that executioner caspase activation induced by chemotherapeutic drugs results in loss of DNA methylation and repressive histone modifications in the CDH12 promoter region, leading to increased CDH12 expression. Our work unveils the mechanism underlying anastasis-induced enhancement in breast cancer malignancy, offering new therapeutic targets for preventing post-chemotherapy cancer relapse and metastasis.
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With ever-increasing pursuit for high-value output in recycling spent lithium-ion batteries (LIBs), traditional recycling methods of cathodes tend to be obsolete because of the complicated procedures. Herein, we first upcycle spent polycrystal LiNi0.88 Co0.095 Al0.025 O2 (S-NCA) to high value-added single-crystalline and Li-rich cathode materials through a simple but feasible LiOH-Na2 SO4 eutectic molten salt strategy. The in situ X-ray diffraction technique and a series of paratactic experiments record the evolution process of upcycling and prove that excessive Li occupies the transition metal (TM) layers. Beneficial from the single-crystalline and Li-rich nature, the regenerated NCA (R-NCA) exhibits remarkably enhanced electrochemical performances in terms of long-term cyclability, high-rate performance and low polarization. This approach can also be successfully extended to other cathode materials e.g., LiNix Coy Mnz O2 (NCM) and mixed spent NCAs with varied degree of Li loss.
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Lítio , Cloreto de Sódio , Fontes de Energia Elétrica , Eletrodos , ÍonsRESUMO
ZnS materials exhibit very negative potential of the conduction band, which is promising in photocatalytic reduction reactions. Unfortunately, previously reported ZnS materials for photocatalysis are mainly in the cubic phase, which produce high activity for H2 evolutions and low activity toward CO2 reductions. Herein, a hexagonal phase ZnS photocatalyst is fabricated for highly efficient CO2 reduction reactions. The hexagonal ZnS nanoplates with the pure phase and well crystallization are synthesized via three-step solvothermal methods. In photocatalytic CO2 reduction reactions under an aqueous solution environment, the hexagonal ZnS produces a CO selectivity of 21%, which is distinctly higher than that of 0.2% for commonly used cubic ZnS. The energy band study suggests that hexagonal ZnS possesses a slightly more negative conduction band and wider bandgap than cubic ZnS. Theoretical calculations reveal that the hexagonal ZnS possesses increased electron density around Zn atoms as that of cubic ZnS. Furthermore, hexagonal ZnS exhibits relatively reduced absorption energy of CO2 reduction intermediates and increased absorption energy of H* as cubic ZnS, which result in better selectivity toward CO2 reduction reactions. This study offers deep insights into the synthesis and electronic structure of hexagonal ZnS for CO2 reduction reactions, which inspire the design of highly active photocatalysts for artificial photosynthesis.