Fast Catalyst-Free Synthesis of Stereoselective Polypeptides via Hierarchical Chiral Assembly.

Understanding how life's essential homochiral biopolymers arose from racemic precursors is a challenging quest. Herein, we present a groundbreaking approach involving hierarchical chiral assembly-driven stereoselective ring-opening polymerization of ε-benzyloxycarbonyl-l/d-lysine N-carboxyanhydrides assisted by ultrasonication in an aqueous medium. This method enabled a narrow dispersity within a few minutes and the achievement of high molecular weight for polypeptides, employing a living polymerization mechanism. The polymerization of l and d enantiomers yielded predominantly right- and left-handed superhelical assemblies in a one-pot preparation, respectively. Notably, stereoselective polypeptide segments were efficiently prepared through hierarchical assembly-driven polymerization of racemic monomers in the absence of a catalyst. This research offers an innovative strategy for the convenient preparations of stereoenriched polypeptides and, more importantly, sheds light on the plausible emergence of homochiral peptides in the origin of life.

Dose-response associations of maternal prenatal noise exposure duration with antepartum depression status.

BACKGROUND: Antepartum depression has been reported to be associated with the intensity of maternal prenatal noise exposure; however, the association between noise exposure duration and the development of antepartum depression has not been established. This study aimed to determine the total and trimester-specific association of prenatal noise exposure duration with the development of antepartum depression. METHODS: From May 2018 to June 2021, we recruited 2,166 pregnant women from Shengjing Hospital, northeast China. We used a standardized questionnaire to assess women's prenatal noise exposure and used the Edinburgh Postnatal Depression Scale to assess pregnant women's antepartum depression during the 1st -, 2nd -, and 3rd - trimesters. We calculated a cumulative noise exposure score ranging from 0 to 3, with a higher score reflecting higher frequency and longer duration of noise exposure during pregnancy. RESULTS: Women who were exposed to noise for ≥ 15 min per day had an increased risk of antepartum depression compared with women who were not exposed to noise during pregnancy [odds ratio (OR) = 1.83, 95%CI:1.18, 2.83]. Noise exposure in a specific trimester was associated with higher risk of depression in the same trimester and subsequent trimesters. We observed increases in antepartum depression risk with increasing cumulative noise exposure scores (P for trend < 0.05 for all). Pregnant women with the highest scores had the highest risk of antepartum depression during the first (OR = 1.30, 95%CI:1.02, 1.65), second (OR = 1.75, 95%CI:1.23, 2.50) trimesters. Women with a cumulative noise exposure score of 2 had the highest risk of antepartum depression during the third trimester (OR = 1.79, 95%CI:1.14, 2.80), as well as during the whole pregnancy (OR = 1.94, 95%CI:1.14, 3.30). CONCLUSIONS: Maternal prenatal noise exposure duration was positively associated with antepartum depression risk in a dose-response manner. It is necessary to develop strategies by which pregnant women can avoid excessive exposure to noise to prevent antepartum depression.

Trimester-specific associations of maternal dietary patterns with preterm birth: China Medical University birth cohort study.

The trimester-specific associations of maternal dietary patterns with preterm birth (PTB) are unclear. In a prospective prebirth cohort study, we aimed to examine the critical time window of maternal prenatal dietary patterns and the risk of PTB. We assessed prenatal dietary intake among 1500 pregnant women with validated food frequency questionnaires during the 1st, 2nd and 3rd trimester, respectively. We used logistic regression models and generalized estimating equation models to examine the trimester-specific associations and longitudinal associations between maternal dietary patterns in relation to risk of PTB and PTB subtypes. The incidence rate of PTB was 11.9% (179 out of 1500 pregnant women) in the present study. We observed that maternal adherence to a fish-seafood pattern in the 1st trimester was associated with higher risk of PTB [tertile 3 (T3) vs. tertile 1 (T1): OR = 2.29, 95% CI: 1.32-3.96] and iatrogenic preterm birth (IPTB) (T3 vs. T1: OR = 2.26, 95% CI: 1.21-4.20), while a fish-seafood pattern in the 2nd trimester was associated with lower risk of PTB (T3 vs. T1: OR = 0.49, 95% CI: 0.25-0.93). Maternal adherence to a dairy-egg pattern in the 2nd or 3rd trimester was associated with higher risks of PTB and IPTB. No dietary patterns were associated with spontaneous preterm birth. Our findings provide new evidence that specific dietary patterns during different trimesters may have different and even inverse health effects on pregnant women. This supports the necessity of guiding the maternal diet according to different periods of pregnancy to prevent PTB.

Sweet foods dietary pattern enhances negative associations of perceived indoor air quality during pregnancy with postpartum depression.

Postpartum depression (PPD) is possibly caused by indoor air pollution and may be modified by maternal diet during pregnancy. Using the data from a prospective cohort study, we examined the interaction between indoor air quality and maternal dietary patterns on PPD development. A perceived indoor air quality (PIAQ) score was used to assess indoor air pollution. A higher PIAQ score indicated a worse indoor air quality. Women with higher PIAQ scores were at increased risk for PPD (tertile 3 vs. tertile 1, odds ratio [OR] = 2.12, 95% confidence interval [CI] = 1.37-3.29). Compared with a lower adherence to a "sweet foods pattern" (OR = 1.20, 95% CI = 0.66-2.18), a higher adherence to a "sweet foods pattern" enhanced the hazardous associations of the PIAQ on PPD (OR = 3.09, 95% CI = 1.81-5.27, adjusted p for interaction = 0.044). Higher adherence to a "whole grain-seafood pattern" and lower adherence to a "traditional pattern" also increased the risk for PPD, although the p values for the interaction were not significant. Our findings provide further evidence of the link between diet during pregnancy, air pollution, and PPD, and it can be used to develop PPD prevention strategies.

Trimester-specific association of perceived indoor air quality with antenatal depression: China Medical University Birth Cohort Study.

Antenatal depression is associated with adverse birth and long-term outcomes for mothers and children. Pregnant women spend 90% of time indoors; however, the association between indoor air quality and risk of antenatal depression has not been established. In this study, we aim to determine the total and trimester-specific association of perceived indoor air quality (PIAQ) with antenatal depression. A total of 2166 pregnant women were enrolled during the first trimester and evaluated during the second and third trimesters in the China Medical University Birth Cohort Study, a prospective pre-birth cohort study in northeastern China. PIAQ scores were obtained during each of three trimesters, which a higher score indicated a worse indoor air quality. Antenatal depression was screened using an Edinburgh Postnatal Depression Scale (EPDS) and defined as an EPDS score ≥ 9. Prevalence of antenatal depression was 26.7%, 20.6%, and 20.9% during the first, second, and third trimesters, respectively. A higher PIAQ score was positively associated with a depression score throughout pregnancy (ß = 0.27, 95% CI = 0.15-0.39). Trimester-specific adverse PIAQ exposure was associated with a higher depression score in the same trimester, but not with a higher score in a subsequent trimester. A dose-response pattern and incremental increases in risk of depression were observed with calculated adverse PIAQ exposures across all three trimesters, with the highest risk (OR = 3.24; 95% CI = 2.28-4.78) among women with adverse PIAQ across all three trimesters. The hazardous association between adverse PIAQ exposure and risk of depression were less pronounced among women with higher physical activity levels (P for interaction < 0.001). The results of present study provided important evidence that pregnant women's mental health was linked to indoor air quality during pregnancy. These findings could be helpful in the development of guidelines to prevent antenatal depression by improving indoor air quality.

A study on the catalytic activity of polypeptides toward the hydrolysis of glucoside compounds gastrodin, polydatin and esculin.

The self-assembly of a series of catalytically active polypeptides toward hydrolysis of glucoside compounds, namely, gastrodin, polydatin and esculin was investigated. These active peptides are composed of two functional fragments: one is the hydrophobic sequence LHLHLRL, which forms assembling segments in the presence of Zn ions (Zn2+); another functional sequence of active peptides are catalytic sites such as Glu (E), Asp (D) and His (H), where carboxylic acids (-COOH) or imidazole groups act like scissors to cleave glucoside bonds of the compounds (according to the acid-base coupling mechanism). The effects of the amino acid sequence of the peptide, Zn2+ concentration, pH and the size or steric hindrance of glucoside compounds on the hydrolytic activity were studied. It was found that the crystalline structure of assembled peptides was crucial to provide the peptide with catalytic hydrolytic activity. Noncovalent interaction index was used to analyse the noncovalent interaction of PEs with glucoside compounds, including hydrogen bonds, van der Waals, and steric effect in the complexes. The binding energy of complexes, the direction and site of nucleophilic attack during deglycosylation processes were also investigated by molecular docking and the electron density Laplace function. This revealed that the differences in the hydrolytic activity of peptides toward glucoside compounds with different sizes originated from different hydrogen bond interactions between the peptides and substrates. These active peptides may find application in the preparation of drugs by de-glycosylation of natural compounds.

Associations of Dietary Patterns during Pregnancy with Gestational Hypertension: The "Born in Shenyang" Cohort Study.

The literature on maternal dietary patterns and gestational hypertension (GH) risk is largely ambiguous. We investigated the associations of maternal dietary patterns with GH risk among 1092 pregnant women in a Chinese pre-birth cohort. We used both three-day food diaries (TFD) and food frequency questionnaires (FFQ) to assess the diets of pregnant women. Principal components analysis with varimax rotation was used to identify dietary patterns from the TFD and FFQ, respectively. In total, 14.5% of the participants were diagnosed with GH. Maternal adherence to a "Wheaten food−coarse cereals pattern (TFD)" was associated with a lower risk of GH (quartile 3 [Q3] vs. Q1, odds ratio [OR] = 0.53, 95%CI: 0.31, 0.90). Maternal adherence to a "Sweet food−seafood pattern (TFD)" was associated with lower systolic blood pressure (Q4 vs. Q1, ß = −2.57, 95%CI: −4.19, −0.96), and mean arterial pressure (Q4 vs. Q1, ß = −1.54, 95%CI: −2.70, −0.38). The protective associations of the "Sweet food-seafood (TFD)" and "Fish−seafood pattern (FFQ)" with the risk of GH were more pronounced among women who were overweight/obese before pregnancy (p for interaction < 0.05 for all). The findings may help to develop interventions and better identify target populations for hypertension prevention during pregnancy.

Nanoscale TiO2 Coatings Improve the Stability of an Earth-Abundant Cobalt Oxide Catalyst during Acidic Water Oxidation.

The large-scale deployment of proton-exchange membrane water electrolyzers for high-throughput sustainable hydrogen production requires transition from precious noble metal anode electrocatalysts to low-cost earth-abundant materials. However, such materials are commonly insufficiently stable and/or catalytically inactive at low pH, and positive potentials required to maintain high rates of the anodic oxygen evolution reaction (OER). To address this, we explore the effects of a dielectric nanoscale-thin layer, constituted of amorphous TiO2, on the stability and electrocatalytic activity of nanostructured OER anodes based on low-cost Co3O4. We demonstrate a direct correlation between the OER performance and the thickness of the atomic layer deposited TiO2 layers. An optimal TiO2 layer thickness of 4.4 nm enhances the anode lifetime by a factor of ca. 3, achieving 80 h of continuous electrolysis at pH near zero, while preserving high OER catalytic activity of the bare Co3O4 surface. Thinner and thicker TiO2 layers decrease the stability and activity, respectively. This is attributed to the pitting of the TiO2 layer at the optimal thickness, which allows for access to the catalytically active Co3O4 surface while stabilizing it against corrosion. These insights provide directions for the engineering of active and stable composite earth-abundant materials for acidic water splitting for high-throughput hydrogen production.

The Association between Dietary Patterns and Pre-Pregnancy BMI with Gestational Weight Gain: The "Born in Shenyang" Cohort.

The reported associations of maternal dietary patterns during pregnancy with gestational weight gain are inconsistent, especially among the less studied Asian Chinese populations. In a prospective pre-birth cohort study conducted in northern China, we determined the associations between maternal dietary patterns and the probability of excess gestational weight gain (EGWG) among 1026 pregnant women. We used 3-day food diaries to assess maternal diet and performed principal component analysis to identify dietary patterns. Maternal adherence to a traditional pattern, which was characterized by a higher intake of tubers, vegetables, fruits, red meat, and rice, was associated with a higher probability of EGWG (quartile 3 vs. quartile 1, odds ratio [OR] = 1.62, 95% confidence interval [CI] = 1.10−2.38). This risk association was more pronounced among women who were overweight/obese before pregnancy (quartile 4 vs. quartile 1, OR = 5.17, 95% CI = 1.45−18.46; p for interaction < 0.01). Maternal adherence to a high protein pattern, which was characterized by a higher intake of fried foods, beans and bean products, dairy products, and fruits, was associated with a lower risk of EGWG (quartile 3 vs. quartile 1, OR = 0.56, 95% CI, 0.39−0.81). The protective association was more pronounced among non-overweight/obese women (p for interaction < 0.01). These findings may help to develop interventions and better define target populations for EGWG prevention.

Covalent Coupling-Stabilized Transition-Metal Sulfide/Carbon Nanotube Composites for Lithium/Sodium-Ion Batteries.

Transition-metal sulfides (TMSs) powered by conversion and/or alloying reactions are considered to be promising anode materials for advanced lithium-ion batteries (LIBs) and sodium-ion batteries (SIBs). However, the limited electronic conductivity and large volume expansion severely hinder their practical application. Herein, we report a covalent coupling strategy for TMS-based anode materials using amide linkages to bind TMSs and carbon nanotubes (CNTs). In the synthesis, the thiourea acts as not only the capping agent for morphology control but also the linking agent for the covalent coupling. As a proof of concept, the covalently coupled ZnS/CNT composite (CC-ZnS/CNT) has been prepared, with ZnS nanoparticles (∼10 nm) tightly anchored on CNT bundles. The compact ZnS-CNT heterojunctions are greatly beneficial to facilitating the electron/ion transfer and ensuring structural stability. Due to the strong coupling interaction between ZnS and CNTs, the composite presents prominent pseudocapacitive behavior and highly reversible electrochemical processes, thus leading to superior long-term stability and excellent rate capability, delivering reversible capacities of 333 mAh g-1 at 2 A g-1 over 4000 cycles for LIBs and 314 mAh g-1 at 5 A g-1 after 500 cycles for SIBs. Consequently, CC-ZnS/CNT exhibits great competence for applications in LIBs and SIBs, and the covalent coupling strategy is proposed as a promising approach for designing high-performance anode materials.

Hierarchical Metal-Organic Framework Films with Controllable Meso/Macroporosity.

The structuring of the metal-organic framework material ZIF-8 as films and membranes through the vapor-phase conversion of ZnO fractal nanoparticle networks is reported. The extrinsic porosity of the resulting materials can be tuned from 4% to 66%, and the film thickness can be controlled from 80 nm to 0.23 mm, for areas >100 cm2. Freestanding and pure metal-organic frameworks (MOF) membranes prepared this way are showcased as separators that minimize capacity fading in model Li-S batteries.

Janus Conductive/Insulating Microporous Ion-Sieving Membranes for Stable Li-S Batteries.

Lithium-sulfur batteries are one of the most promising next-generation high-density energy storage systems. Despite progress, the poor electrical conductivity and cycling stability of sulfur cathodes still hinder their practical implementation. Here, we developed a facile approach for the engineering of Janus double-sided conductive/insulating microporous ion-sieving membranes that significantly enhance recharge efficiency and long-term stability of Li-S batteries. Our membrane consists of an insulating Li-anode side and an electrically conductive S-cathode side. The insulating side consists of a standard polypropylene separator, while the conductive side is made of closely packed multilayers of high-aspect-ratio MOF/graphene nanosheets having a thickness of few nanometers and a specific surface area of 996 m2 g-1 (MOF, metal-organic framework). Our models and experiments reveal that this electrically conductive microporous nanosheet architecture enables the reuse of polysulfide trapped in the membrane and decreases the polysulfide flux and concentration on the anode side by a factor of 250× over recent microporous membranes made of granular MOFs and standard battery separators. Notably, Li-S batteries using our Janus microporous membranes achieve an outstanding rate capability and long-term stability with 75.3% capacity retention over 1700 cycles. We demonstrate the broad applicability of our high-aspect-ratio MOF/graphene nanosheet preparation strategy by the synthesis of a diverse range of MOFs, including ZIF-67, ZIF-8, HKUST-1, NiFe-BTC, and Ni-NDC, providing a flexible approach for the design of Janus microporous membranes and electrically conductive microporous building blocks for energy storage and various other electrochemical applications.

Rice busk biochar treatment to cobalt-polluted fluvo-aquic soil: speciation and enzyme activities.

Rice busk biochar was mixed with cobalt (Co)-polluted soil to examine the efficacy of biochar for Co immobilization and detoxification in fluvo-aquic soil. The Co speciation (modified BCR sequential extraction), fluorescein diacetate (FDA) hydrolysis and soil enzyme activities were investigated. In soil, the Co ions (acid-soluble fraction) could be uptake by biochar due to the microporous structure on the surface, as well as the oxygen-containing functional groups and conjugated structure in the molecular structure. Therefore, when the biochar concentration was lower than the optimum concentration (~6 g·kg-1), there was transformation of Co from the acid-soluble fraction to the oxidizable fraction, resulting in lower environmental risk. However, if the biochar concentration continued increasing, the distribution coefficient of Co in the acid-soluble fraction increased (P < 0.05). The biochar could also reduce the toxicity of Co, resulting in the negative correlations between soil enzyme activities (FDA hydrolysis, urease and alkaline phosphatases) and Co in the acid-soluble fraction (r = -0.816, -0.928 and -0.908, respectively, P < 0.01). When the biochar concentration ranged from 5.83 to 6.76 g·kg-1, the efficacy for Co immobilization and detoxification reached the maxima. To conclude, in fluvo-aquic soil, rice busk biochar is an effective amendment for immobilizing Co ions and reducing the toxicity of Co. The biochar concentration in soil should range from 5.83 to 6.76 g·kg-1 to reach the optimum efficacy.

Maleic, glycolic and acetoacetic acids-leaching for recovery of valuable metals from spent lithium-ion batteries: leaching parameters, thermodynamics and kinetics.

Environmentally friendly acid-leaching processes with three organic acids (maleic, glycolic and acetoacetic) were developed to recover valuable metals from the cathodic material of spent lithium-ion batteries (LiCoO2). The leaching efficiencies of Li and Co by the maleic acid were 99.58% and 98.77%, respectively. The leaching efficiencies of Li and Co by the glycolic acid were 98.54% and 97.83%, while those by the acetoacetic acid were 98.62% and 97.99%, respectively. The optimal acid concentration for the maleic acid-, glycolic acid- and acetoacetic acid-leaching processes were 1, 2 and 1.5 mol l-1, respectively, while their optimal H2O2 concentrations were 1.5, 2 and 1.5 vol%, respectively. The optimal solid/liquid ratio, temperature and reaction time for the leaching process of the three organic acids was the same (10 g l-1, 70°C, 60 min). The thermodynamic formation energy of the leaching products and the Gibbs free energy of the leaching reactions were calculated, and the kinetic study showed that the leaching processes fit well with the shrinking-core model. Based on the comparison in the leaching parameters, the efficacy and availability of the three acids is as follows: maleic acid > acetoacetic acid > glycolic acid.

Metal-Organic Frameworks/Conducting Polymer Hydrogel Integrated Three-Dimensional Free-Standing Monoliths as Ultrahigh Loading Li-S Battery Electrodes.

The lithium-sulfur (Li-S) system is a promising material for the next-generation of high energy density batteries with application extending from electrical vehicles to portable devices and aeronautics. Despite progress, the energy density of current Li-S technologies is still below that of conventional intercalation-type cathode materials due to limited stability and utilization efficiency at high sulfur loading. Here, we present a conducting polymer hydrogel integrated highly performing free-standing three-dimensional (3D) monolithic electrode architecture for Li-S batteries with superior electrochemical stability and energy density. The electrode layout consists of a highly conductive three-dimensional network of N,P codoped carbon with well-dispersed metal-organic framework nanodomains of ZIF-67 and HKUST-1. The hierarchical monolithic 3D carbon networks provide an excellent environment for charge and electrolyte transport as well as mechanical and chemical stability. The electrically integrated MOF nanodomains significantly enhance the sulfur loading and retention capabilities by inhibiting the release of lithium polysulfide specificities as well as improving the charge transfer efficiency at the electrolyte interface. Our optimal 3D carbon-HKUST-1 electrode architecture achieves a very high areal capacity of >16 mAh cm-2 and volumetric capacity (CV) of 1230.8 mAh cm-3 with capacity retention of 82% at 0.2C for over 300 cycles, providing an attractive candidate material for future high-energy density Li-S batteries.

Cobalt speciation and phytoavailability in fluvo-aquic soil under treatments of spent mushroom substrate from Pleurotus ostreatus.

Cobalt (Co) is a nutrient for soil microorganisms and crops, as well as a worldwide industrial pollutant. When the level of Co exceeds the acceptable limit, this heavy metal can lead to devastating consequences for soil environments. There is considerable attention and concern about elevated levels of Co contaminating soil and crops. Spent mushroom substrate (SMS) is a potential amendment for the adsorption of pollutants, which has potential for resolving Co-polluted soil that spans the world. To investigate the environmental behavior and risks associated with Co in fluvo-aquic soil under specific treatments of SMS from Pleurotus ostreatus, a lab-scale pot experiment was conducted. SMS and exogenous Co were added to soil, which was retained for approximately 30 days. Pakchois (Brassica chinensis L.) were planted in the treated soil for 28 days until harvest. The Co speciation in soil (modified BCR sequential extraction) and Co accumulation in pakchoi tissue were studied. When the SMS concentration was within a range of 0 to 9 g kg-1 (total amount = 0 to 2.7 g), Co in the acid-soluble fraction was transformed to the oxidizable fraction in soil, resulting from the mesh structure on the surface of SMS, as well as the amide and carboxyl in the SMS molecular structure. In this situation, the Co accumulation levels in the pakchois decreased significantly (P < 0.05), indicating the efficacy of SMS for reducing Co phytoavailability. However, when the SMS concentration reached 12 g kg-1, the phytoavailability increased again (P < 0.05). When the SMS concentration ranged from 8.86 to 9.51 g kg-1, the Co phytoavailability in soil reached a minimum, while the biomass of pakchoi reached a maximum. Conclusively, SMS from Pleurotus ostreatus are effective for reducing the Co phytoavailability, as well as for reducing the chance of Co transferring into a human's body through crops (i.e., food consumption). In order to achieve the optimum efficacy, the SMS concentration in soil should be maintained at a range of 8.86 to 9.51 g kg-1.

The effect of U speciation in cultivation solution on the uptake of U by variant Sedum alfredii.

In the present study, five plant species were screened for uranium uptake using a hydroponic experimental set-up. The effect of the U concentration, pH, as well as the presence of carbonates, phosphates, and organic acids (lactic acid, malic acid, citric acid) on the uptake of U by variant S. alfredii (V S. alfredii) and wild S. alfredii (W S. alfredii) were investigated. Results showed that V S. alfredii exhibited higher U content in the roots than the other four plants and with the increase of U concentration in the solution, the U uptake by V S. alfredii and W S. alfredii increased. The results also showed that different U speciation in different cultivation solution took an important role on the uptake of U in variant Sedum alfredii: at pH 6.5, U hydrolysis species (UO2)3(OH)5 (+)is predominant and the U concentrations in V S. alfredii roots reached a maximum value (3.7 × 10(4) mg/kg). U complexation with carbonates, phosphates, and some organic acids in the solution resulted in a decrease in the U content in the roots except for lactic acid. Our researches highlight the correlations between U speciation and the uptake on V S. Alfredii, which will be helpful for improved removal of U from the groundwater using phytoremediation method.

Surface Coating Constraint Induced Self-Discharging of Silicon Nanoparticles as Anodes for Lithium Ion Batteries.

One of the key challenges of Si-based anodes for lithium ion batteries is the large volume change upon lithiation and delithiation, which commonly leads to electrochemi-mechanical degradation and subsequent fast capacity fading. Recent studies have shown that applying nanometer-thick coating layers on Si nanoparticle (SiNPs) enhances cyclability and capacity retention. However, it is far from clear how the coating layer function from the point of view of both surface chemistry and electrochemi-mechanical effect. Herein, we use in situ transmission electron microscopy to investigate the lithiation/delithiation kinetics of SiNPs coated with a conductive polymer, polypyrrole (PPy). We discovered that this coating layer can lead to "self-delithiation" or "self-discharging" at different stages of lithiation. We rationalized that the self-discharging is driven by the internal compressive stress generated inside the lithiated SiNPs due to the constraint effect of the coating layer. We also noticed that the critical size of lithiation-induced fracture of SiNPs is increased from ∼150 nm for bare SiNPs to ∼380 nm for the PPy-coated SiNPs, showing a mechanically protective role of the coating layer. These observations demonstrate both beneficial and detrimental roles of the surface coatings, shedding light on rational design of surface coatings for silicon to retain high-power and high capacity as anode for lithium ion batteries.

Coaxial CoMoO4 nanowire arrays with chemically integrated conductive coating for high-performance flexible all-solid-state asymmetric supercapacitors.

Flexible all-solid-state supercapacitors have offered promising applications as novel energy storage devices based on their merits, such as small size, low cost, light weight and high wearability for high-performance portable electronics. However, one major challenge to make flexible all-solid-state supercapacitors depends on the improvement of electrode materials with higher electrical conductivity properties and longer cycling stability. In this article, we put forward a simple strategy to in situ synthesize 1D CoMoO4 nanowires (NWs), using highly conductive CC and an electrically conductive PPy wrapping layer on CoMoO4 NW arrays for high performance electrode materials. The results show that the CoMoO4/PPy hybrid NW electrode exhibits a high areal specific capacitance of ca. 1.34 F cm(-2) at a current density of 2 mA cm(-2), which is remarkably better than the corresponding values for a pure CoMoO4 NW electrode of 0.7 F cm(-2). An excellent cycling performance of nanocomposites of up to 95.2% (ca. 1.12 F cm(-2)) is achieved after 2000 cycles compared to pristine CoMoO4 NWs. In addition, we fabricate flexible all-solid-state ASC which can be cycled reversibly in the voltage range of 0-1.7 V, and exhibits a maximum energy density of 104.7 W h kg(-1) (3.522 mW h cm(-3)), demonstrating great potential for practical applications in flexible energy storage electronics.

Morphology-tunable ultrafine metal oxide nanostructures uniformly grown on graphene and their applications in the photo-Fenton system.

Hybrid nanostructures of low-dimensional metal oxide (MO) semiconductors based on two-dimensional (2D) graphene nanosheets have been considered as one of the most promising nanomaterials for an extensive variety of applications. Unfortunately, it is still challenging to rationally design and fabricate MO/graphene hybrids with highly controllable nanostructures and desirable properties, which are of paramount importance for practical applications. Here, we report a novel, facile and "green" glycerol-mediated self-assembly method, using α-Fe2O3 semiconductor as an illustrative example, for the controlled growth of MO with a well-defined nanostructure on 2D graphene nanosheets. Based on this new method, we first demonstrate the ability to exquisitely tune the α-Fe2O3 nanostructure from zero-dimensional quantum dots (∼3.2 nm) to one-dimensional mesoporous nanorods, and eventually to 2D mesoporous nanosheets over the entire surface of graphene nanosheets. A possible formation mechanism has been proposed based on the systematic investigation of the morphological evolution and growth processes of α-Fe2O3 on graphene. The as-synthesized samples exhibit excellent performance for the photo-Fenton treatment of polluted water at neutral pH under visible light irradiation. Moreover, TiO2 and Fe3O4 quantum dots (∼5.2 and 3.3 nm, respectively) ultradispersed on graphene are also successfully synthesized by this method, demonstrating its versatility for the rational fabrication of novel MO/graphene hybrids with huge potential applications.