Pyoderma gangrenosum complicated with hematological malignancies: Two case reports.

INTRODUCTION: Pyoderma gangrenosum (PG) is a rare noninfectious neutrophilic skin disease. The diagnosis of PG is mainly based on clinical manifestations. Therefore, the clinical features of PG are important for confirming the diagnosis of this disease. Herein, the clinical data of 2 young males with PG complicated with hematological malignancies were reported, and the literature were reviewed. CASE PRESENTATION: The first case was a 22-year-old male who was admitted due to a systemic rash, headache, and fever. Physical examination showed black scabs on the skins of the extremities, trunk, scalp, and face. Biopsy of the skin lesion showed epidermal edema, spongy formation, neutrophil infiltration, acute and chronic inflammatory cell infiltration in the dermis, showing purulent inflammation with epidermal erosion. The bone marrow biopsy showed obviously active proliferation of nucleated cells, granulocytes at various stages, abnormal morphological neutrophils, and occasionally observed young red blood cells. The diagnosis of PG and chronic myelomonocytic leukemia (CMML-0) was made. The second case was a 28-year-old male who presented a swollen, painful right calf following injury and then developed ulcers on skin and soft tissues. Bone marrow biopsy showed obviously active nucleated cell proliferation, suggesting a myeloid tumor. He was also diagnosed with PG and hematological malignancies. They both received hormone and antiinfection therapy. After treatment, their body temperature, infection, and skin lesions were improved. However, both of them were readmitted and had a poor prognosis. CONCLUSIONS: PG may be associated with hematological malignancies. For patients with typical skin lesions and obvious abnormal blood routines, it is necessary to investigate the possibility of PG with hematological malignancies.

Correlating the Microstructure and Current Density of the Li/Garnet Interface.

Solid-state lithium batteries hold great promise for next-generation energy storage systems. However, the formation of lithium filaments within the solid electrolyte remains a critical challenge. In this study, we investigate the crucial role of morphology in determining the resistance of garnet-type electrolytes to lithium filaments. By proposing a new test method, namely, cyclic linear sweep voltammetry, we can effectively evaluate the electrolyte resistance against lithium filaments. Our findings reveal a strong correlation between the microscopic morphology of the solid electrolyte and its resistance to lithium filaments. Samples with reduced pores and multiple grain boundaries demonstrate remarkable performance, achieving a critical current density of up to 3.2 mA cm-2 and excellent long-term cycling stability. Kelvin probe force microscopy and finite element method simulation results shed light on the impact of grain boundaries and electrolyte pores on lithium-ion transport and filament propagation. To inhibit lithium penetration, minimizing pores and achieving a uniform morphology with small grains and plenty of grain boundaries are essential.

[Comparison of pulse oxygen saturation/fraction of inhaled oxygen and arterial partial pressure of oxygen/fraction of inhaled oxygen in the assessment of oxygenation in acute respiratory distress syndrome patients at different high altitudes in Yunnan Province].

OBJECTIVE: To investigate and evaluate if pulse oxygen saturation/fraction of inhaled oxygen (SpO2/FiO2) can be used, as replacement of arterial partial pressure of oxygen/fraction of inhaled oxygen (PaO2/FiO2), to assess oxygenation in acute respiratory distress syndrome (ARDS) patients at different high altitudes in Yunnan Province, and to find a rapid and non-invasive method for the diagnosis of ARDS at different altitudes. METHODS: Patients with ARDS at different high altitudes in Yunnan Province from January 2019 to December 2020 were enrolled. The patients were divided into three groups according to different altitudes, and received different oxygen therapies according to their respective medical conditions. Group 1 consisted of patients with moderate to severe ARDS from the department of critical care medicine of the First Affiliated Hospital of Kunming Medical University (average altitude approximately 1 800 m), and received mechanical ventilation to maintain SpO2 of 0.90-0.96 with a low FiO2 for more than 30 minutes, and SpO2, FiO2, PaO2 were recorded. Group 2 consisted of patients with moderate to severe ARDS at the department of critical care medicine of People's Hospital of Diqing Tibetan Autonomous Prefecture (mean altitude about 3 200 m), and received oxygen with an attached reservoir mask to maintain SpO2 of 0.90-0.96 for 10 minutes, and then SpO2, FiO2, and PaO2 were recorded. Group 3 consisted of patients with mild to moderate-severe ARDS who admitted to the emergency department of the People's Hospital of Lijiang (average altitude approximately 2 200 m); when SpO2 < 0.90, patients received oxygen with the oxygen storage mask, and the FiO2 required to maintain SpO2 ≥ 0.90 was recorded, and SpO2, FiO2, PaO2 were recorded after oxygen inhalation for 10 minutes. Spearman coefficient was used to analyze the correlation between SpO2/FiO2 and PaO2/FiO2 in each group. Linear analysis was used to derive the linear equation between SpO2/FiO2 and PaO2/FiO2, and to evaluate arterial pH, arterial partial pressure of carbon dioxide (PaCO2), FiO2, tidal volume (VT), positive end-expiratory pressure (PEEP) and other related factors which would change the correlation between SpO2/FiO2 and PaO2/FiO2. The receiver operator characteristic curve (ROC curve) was plotted to calculate the sensitivity and specificity of using SpO2/FiO2 instead of PaO2/FiO2 to assess oxygenation of ARDS patients. RESULTS: Group 1 consisted of 24 ARDS patients from whom 271 blood gas analysis results were collected; group 2 consisted of 14 ARDS patients from whom a total of 47 blood gas analysis results were collected; group 3 consisted of 76 ARDS patients, and a total of 76 blood gas analysis results were collected. The PaO2/FiO2 (mmHg, 1 mmHg = 0.133 kPa) in groups 1, 2 and 3 were 103 (79, 130), 168 (98, 195) and 232 (146, 271) respectively, while SpO2/FiO2 were 157 (128, 190), 419 (190, 445) and 319 (228, 446) respectively. Among the three groups, patients in group 1 had the lowest PaO2/FiO2 and SpO2/FiO2, while patients in group 3 had the highest. Spearman correlation analysis showed that PaO2/FiO2 was highly correlated with SpO2/FiO2 in groups 1, 2 and 3 (r values were 0.830, 0.951, 0.828, all P < 0.05). Regression equation was fitted according to linear analysis: in group 1 SpO2/FiO2 = 58+0.97×PaO2/FiO2 (R2 = 0.548, P < 0.001); in group 2 SpO2/FiO2 = 6+2.13×PaO2/FiO2 (R2 = 0.938, P < 0.001); in group 3 SpO2/FiO2 = 53+1.33×PaO2/FiO2 (R2 = 0.828, P < 0.001). Further analysis revealed that PEEP, FiO2, and arterial blood pH could affect the correlation between SpO2/FiO2 and PaO2/FiO2. ROC curve analysis showed that the area under ROC curve (AUC) was 0.848 and 0.916 in group 1 with moderate to severe ARDS; based on the regression equation, the corresponding SpO2/FiO2 cut-off values at a PaO2/FiO2 of 100 mmHg and 200 mmHg were 155, 252 with a sensitivity of 84.9% and 100%, specificity of 87.2% and 70.6%, respectively. Patients with moderate to severe ARDS in group 2 (AUC was 0.945 and 0.977), the corresponding SpO2/FiO2 cut-off values at PaO2/FiO2 of 100 mmHg and 200 mmHg were 219 and 432 with the sensitivity of 100% and 85.2%, specificity of 82.5% and 100%, respectively. Patients with mild to moderate-severe ARDS in group 3 (AUC was 0.903 and 0.936), the corresponding SpO2/FiO2 cut-off values at a PaO2/FiO2 of 200 mmHg and 300 mmHg were 319 and 452 with the sensitivity of 100% and 100%, specificity of 80.9% and 86.2%, respectively. CONCLUSIONS: SpO2/FiO2 and PaO2/FiO2 in ARDS patients at different high altitudes in Yunnan Province have a good correlation, and non-invasive SpO2/FiO2 can be used to replace PaO2/FiO2 to assess the oxygenation in ARDS patients.

Li/Garnet Interface Optimization: An Overview.

Solid-state lithium batteries can improve the safety and energy density of the present liquid-electrolyte-based lithium-ion batteries. To achieve this goal, both solid electrolyte and lithium anode technology are the keys. Lithium garnet is a promising electrolyte to enable the next generation solid-state lithium batteries due to its high ionic conductivity, good chemical, and electrochemical stability, and easiness to scale up. It is relatively stable against Li metal but the poor contact area and the presence of resistive impurity or decomposition layers at the interface interfere with fast charge transfer, thereby, spiking the interfacial resistance, overpotential, local current density, and the propensity for dendrite growth. In this Review, we first summarize the recent understanding of the interfacial problems at the Li/garnet interface from both computational and experimental viewpoints while seizing the opportunity to shed light on the chemical/electrochemical stability of garnet against Li metal anode. Also, we highlight various interface optimization strategies that have been demonstrated to be effective in improving the interface performance. We conclude this Review with a few suggestions as guides for future work.

The stability of P2-layered sodium transition metal oxides in ambient atmospheres.

Air-stability is one of the most important considerations for the practical application of electrode materials in energy-harvesting/storage devices, ranging from solar cells to rechargeable batteries. The promising P2-layered sodium transition metal oxides (P2-NaxTmO2) often suffer from structural/chemical transformations when contacted with moist air. However, these elaborate transitions and the evaluation rules towards air-stable P2-NaxTmO2 have not yet been clearly elucidated. Herein, taking P2-Na0.67MnO2 and P2-Na0.67Ni0.33Mn0.67O2 as key examples, we unveil the comprehensive structural/chemical degradation mechanisms of P2-NaxTmO2 in different ambient atmospheres by using various microscopic/spectroscopic characterizations and first-principle calculations. The extent of bulk structural/chemical transformation of P2-NaxTmO2 is determined by the amount of extracted Na+, which is mainly compensated by Na+/H+ exchange. By expanding our study to a series of Mn-based oxides, we reveal that the air-stability of P2-NaxTmO2 is highly related to their oxidation features in the first charge process and further propose a practical evaluating rule associated with redox couples for air-stable NaxTmO2 cathodes.

Difference in hematocrit and plasma albumin levels as an additional biomarker in the diagnosis of infectious disease.

INTRODUCTION: In clinical practice, it has been observed that patients with severe infections show changes to their hematocrit (HCT) and serum albumin (ALB) levels. This study aimed to evaluate whether the difference of HCT and ALB (HCT-ALB) levels can be used as an additional biomarker for fast diagnosis of severe infections. MATERIAL AND METHODS: This was a retrospective case-control study which included adult patients with severe infections, patients with non-infective conditions and healthy individuals. A total of 7,117 individuals were recruited in Yunnan Province, China, from January 2012 to January 2018, and were divided into three groups: 1,033 patients with severe infections (group 1); 1,081 patients with non-infective conditions (group 2); and 5,003 healthy individuals from the general population (group 3). The potential diagnostic threshold of HCT-ALB for severe infectious patients was determined by the receiver operating characteristic (ROC) curve analysis. Group 3 was used as the reference to draw the ROC curves of the HCT-ALB value in group 1 or group 2. RESULTS: HCT-ALB values in each group were significantly different. We found that the area under the ROC curve (AUC) of group 1 reached 0.87 (95% CI: 0.86-0.89), whereas the AUC of group 2 was 0.60 (95% CI: 0.58-0.62). To reach a higher specificity of 99.0% (95% CI: 98.8-99.3%, and with sensitivity of 37.5%, 95% CI: 34.5-40.5%), a HCT-ALB value of 10.25 was recommended as the standard for diagnosis of severe infection. CONCLUSIONS: The HCT-ALB value was increased in patients with infectious disease. The measurement of the HCT-ALB value (> 10.25) might be useful in the fast diagnosis of infectious disease.

[Feasibility study of the difference between hematocrit and albumin for identifying hemorrhagic shock and septic shock].

OBJECTIVE: To observe the difference between hematocrit (Hct) and albumin (Alb) levels (Hct-Alb) in hemorrhagic shock and septic shock, and to provide a quick and simple method for differentiating hemorrhagic shock from septic shock. METHODS: 270 shock patients admitted to intensive care unit (ICU) of the First Affiliated Hospital of Kunming Medical University from August 2012 to August 2018, including 124 patients with hemorrhagic shock and 148 patients with septic shock, were enrolled. 148 patients underwent routine physical examination served as a control healthy group. General information such as gender, age, and body mass index (BMI) of the patient were collected. Hct and serum Alb levels on the day of physical examination or onset before blood products transfusion were recorded, and the Hct-Alb difference was calculated. The Hct-Alb differences among the three groups were compared. The receiver operating characteristic (ROC) curve was plotted to analyze the differential diagnosis value of Hct-Alb difference for shock type. RESULTS: All patients were enrolled in the final analysis. Compared with the healthy control group, the patients with hemorrhagic and septic shock were older (years: 50.0±19.8, 59.9±16.9 vs. 42.5±13.6, both P < 0.01), and those patients with septic shock was significantly older than those with hemorrhagic shock (years: 59.9±16.9 vs. 50.0±19.8, P < 0.01). There were no significant differences in gender or BMI among the three groups. Compared with the healthy control group, Hct and Alb values in hemorrhagic shock group and septic shock group were significantly decreased [Hct: (27.9±8.4)%, (35.5±7.1)% vs. (47.0±4.4)%, Alb (g/L): 28.9±7.1, 23.3±5.8 vs. 45.4±4.3, all P < 0.01]. The Hct-Alb difference in the septic shock group was significantly higher than that in the healthy control group (12.1±7.5 vs. 1.6±5.9, P < 0.01), but no significant difference was found between hemorrhagic shock group and healthy control group (-0.9±5.3 vs. 1.6±5.9, P > 0.05). Compared with hemorrhagic shock group, the Alb level in septic shock group was significantly decreased (g/L: 23.3±5.8 vs. 28.9±7.1, P < 0.01), and Hct and Hct-Alb difference were significantly increased [Hct: (35.5±7.1)% vs. (27.9±8.4)%, Hct-Alb difference: 12.1±7.5 vs. -0.9±5.3, both P < 0.01]. It was shown by ROC curve analysis that the area under the ROC curve (AUC) for diagnosing hemorrhagic shock and septic shock was 0.366 and 0.867, indicating that Hct-Alb difference had diagnostic value only for septic shock. When the best cut-off value of Hct-Alb difference was 6.8, the sensitivity was 79.5% for diagnosing septic shock, and the specificity was 79.7%, the positive predict value was 0.80, the negative predict value was 0.80, the positive likelihood ratio was 3.916, the negative likelihood ratio was 0.257. CONCLUSIONS: The Hct-Alb difference in patients with septic shock is higher than that in patients with hemorrhagic shock. The Hct-Alb difference is highly accurate in diagnosing septic shock. When the Hct-Alb difference is greater than 6.8, it can be used for differential diagnosis of hemorrhagic shock and septic shock.

Low-Weight 3D Al2 O3 Network as an Artificial Layer to Stabilize Lithium Deposition.

Lithium metal has been regarded as an ideal anode for high-energy-density batteries. However, safety and efficiency concerns still linger due to dendrite formation, reactions between the liquid electrolyte and lithium, high resistance with lithium metal, and the weight of interface layer. A new nanometer-thick, hollow, Al2 O3 fiber network with an elastic and porous 3D structure has been prepared through an atomic-layer deposition process by using cotton sacrificial templates. Through a comparison study of the lithium deposition behavior by employing artificial layers with different structures, the low-weight 3D layer with lithiophilic properties overcomes the issues resulting from the 2D rigid Al2 O3 layer and provides a low overpotential and dendrite-free growth of lithium metal. Moreover, stable lithium deposition enables Li-Li symmetric cells with a 3D artificial layer to be stably cycled 300 times in carbonate-based electrolyte, with superior rate capability, and with a LiNi1/3 Co1/3 Mn1/3 O2 cathode.

High-Coulombic-Efficiency Carbon/Li Clusters Composite Anode without Precycling or Prelithiation.

Lithium metal has attracted much research interest as a possible anode material for high-energy-density lithium-ion batteries in recent years. However, its practical use is severely limited by uncontrollable deposition, volume expansion, and dendrite formation. Here, a metastable state of Li, Li cluster, that forms between LiC6 and Li dendrites when over-lithiating carbon cloth (CC) is discovered. The Li clusters with sizes in the micrometer and submicrometer scale own outstanding electrochemical reversibility between Li+ and Li, allowing the CC/Li clusters composite anode to demonstrate a high first-cycle coulombic efficiency (CE) of 94.5% ± 1.0% and a stable CE of 99.9% for 160 cycles, which is exceptional for a carbon/lithium composite anode. The CC/Li clusters composite anode shows a high capacity of 3 mAh cm-2 contributed by both Li+ intercalation and Li-cluster formation, and excellent cycling stability with a signature sloping voltage profile. Furthermore, the CC/Li clusters composite anode can be assembled into full cells without precycling or prelithiation. The full cells containing bare CC as the anode and excessive LiCoO2 as the cathode exhibit high specific capacity and good cyclic stability in 200 cycles, stressing the advantage of controlled formation of Li clusters.

Porous Co-C Core-Shell Nanocomposites Derived from Co-MOF-74 with Enhanced Electromagnetic Wave Absorption Performance.

The combination of carbon materials and ferrite materials has recently attracted increased interest in microwave absorption applications. Herein, a novel composite with cobalt cores encapsulated in a porous carbon shell was synthesized via a facile sintering process with a cobaltic metal-organic framework (Co-MOF-74) as the precursor. Because of the magnetic loss caused by the Co cores and dielectric loss caused by the carbon shell with a unique porous structure, together with the interfacial polarization between two components, the ferromagnetic composite exhibited enhanced electromagnetic wave absorption performance compared to traditional ferrite materials. With the thermal decomposition temperature of 800 °C, the optimal reflection loss value achieved -62.12 dB at 11.85 GHz with thin thickness (2.4 mm), and the bandwidth ranged from 4.1 to 18 GHz with more than 90% of the microwave that could be absorbed. The achieved performance illustrates that the as-prepared porous Co-C core-shell composite shows considerable potential as an effective microwave absorber.

Fabricating fast triggered electro-active shape memory graphite/silver nanowires/epoxy resin composite from polymer template.

In recent years shape-memory polymers have been under intense investigation due to their unique mechanical, thermal, and electrical properties that could potentially make them extremely valuable in numerous engineering applications. In this manuscript, we report a polymer-template-assisted assembly manufacturing strategy used to fabricate graphite/silver nanowires/epoxy resin (PGSE) composite. In the proposed method, the porous polymer foams work as the skeleton by forming three-dimensional graphite structure, whereas the silver nanowires act as the continuous conductive network. Preliminary testing on hybrid foams after vacuum infusion showed high electrical conductivity and excellent thermal stability. Furthermore, the composites were found to recover their original shape within 60 seconds from the application of a 0.8 V mm-1 electric field. Notably, the reported shape-memory polymer composites are manufactured with readily-available raw materials, they are fast to manufacture, and are shape-controlled.

Stabilization of Garnet/Liquid Electrolyte Interface Using Superbase Additives for Hybrid Li Batteries.

To improve the solid-electrolyte/electrode interface compatibility, we have proposed the concept of hybrid electrolyte by including a small amount of liquid electrolyte in between. In this work, n-BuLi, a superbase, has been found to significantly improve the cycling performance of LiFePO4/Li hybrid cells containing Li7La3Zr1.5Ta0.5O12 (LLZT) and conventional carbonate-based liquid electrolyte. The modified cells have been cycled for 400 cycles at 100 and 200 µA cm-2 at room temperature, indicating excellent solid/liquid electrolyte interface stability. The role of n-BuLi may be 3-fold: to retard the decomposition reaction of LE, to suppress the Li+/H+ exchange, and to lithiate the garnet/LE interface, inhibiting side reactions and enhancing interfacial lithium-ion transport.

Synthesis of Orthorhombic Perovskite-Type ZnSnO3 Single-Crystal Nanoplates and Their Application in Energy Harvesting.

In recent years, lead-free piezoelectric nanogenerators have attracted much attention because of their great potential for harvesting energy from the environment. Here, we report the first synthesis of two-dimensional (2D) single-crystal ZnSnO3 hexagon nanoplates and the fabrication of ZnSnO3 nanoplate-based nanogenerators. The orthorhombic perovskite-structured ZnSnO3 nanoplates with (111) facets of the exposed plate surface are successfully synthesized via a one-step hydrothermal reaction. Piezoelectric nanogenerators are then fabricated using the as-synthesized single-crystal ZnSnO3 nanoplates and poly(dimethylsiloxane) (PDMS). A d33 value as high as 49 pC/N for the ZnSnO3@PDMS composite was obtained without any electrical poling process, which demonstrates that the single-crystal ZnSnO3 nanoplates have a single-domain structure. To the best of our knowledge, this d33 value is also the highest among lead-free piezoelectric composites. A bending strain can induce the piezoelectric nanogenerator (PENG) to generate a large, stable, and sustainable output open circuit voltage of 20 V and a short circuit current of 0.6 µA, which are higher than many other PENGs. The output signals are sufficient to light a single light-emitting diode (LED), which shows the great potential of the material for scavenging mechanical energy from moving entities, such as road vehicles, railway vehicles, and humans.

Hybrid Polymer/Garnet Electrolyte with a Small Interfacial Resistance for Lithium-Ion Batteries.

Li7 La3 Zr2 O12 -based Li-rich garnets react with water and carbon dioxide in air to form a Li-ion insulating Li2 CO3 layer on the surface of the garnet particles, which results in a large interfacial resistance for Li-ion transfer. Here, we introduce LiF to garnet Li6.5 La3 Zr1.5 Ta0.5 O12 (LLZT) to increase the stability of the garnet electrolyte against moist air; the garnet LLZT-2 wt % LiF (LLZT-2LiF) has less Li2 CO3 on the surface and shows a small interfacial resistance with Li metal, a solid polymer electrolyte, and organic-liquid electrolytes. An all-solid-state Li/polymer/LLZT-2LiF/LiFePO4 battery has a high Coulombic efficiency and long cycle life; a Li-S cell with the LLZT-2LiF electrolyte as a separator, which blocks the polysulfide transport towards the Li-metal, also has high Coulombic efficiency and kept 93 % of its capacity after 100 cycles.

Three dimensional Graphene aerogels as binder-less, freestanding, elastic and high-performance electrodes for lithium-ion batteries.

In this work it is shown how porous graphene aerogels fabricated by an eco-friendly and simple technological process, could be used as electrodes in lithium- ion batteries. The proposed graphene framework exhibited excellent performance including high reversible capacities, superior cycling stability and rate capability. A significantly lower temperature (75 °C) than the one currently utilized in battery manufacturing was utilized for self-assembly hence providing potential significant savings to the industrial production. After annealing at 600 °C, the formation of Sn-C-O bonds between the SnO2 nanoparticles and the reduced graphene sheets will initiate synergistic effect and improve the electrochemical performance. The XPS patterns revealed the formation of Sn-C-O bonds. Both SEM and TEM imaging of the electrode material showed that the three dimensional network of graphene aerogels and the SnO2 particles were distributed homogeneously on graphene sheets. Finally, the electrochemical properties of the samples as active anode materials for lithium-ion batteries were tested and examined by constant current charge-discharge cycling and the finding fully described in this manuscript.

Ionic Conductivity and Air Stability of Al-Doped Li7La3Zr2O12 Sintered in Alumina and Pt Crucibles.

Li7La3Zr2O12 (LLZO) is a promising electrolyte material for all-solid-state battery due to its high ionic conductivity and good stability with metallic lithium. In this article, we studied the effect of crucibles on the ionic conductivity and air stability by synthesizing 0.25Al doped LLZO pellets in Pt crucibles and alumina crucibles, respectively. The results show that the composition and microstructure of the pellets play important roles influencing the ionic conductivity, relative density, and air stability. Specifically, the 0.25Al-LLZO pellets sintered in Pt crucibles exhibit a high relative density (∼96%) and high ionic conductivity (4.48 × 10(-4) S cm(-1)). The ionic conductivity maintains 3.6 × 10(-4) S cm(-1) after 3-month air exposure. In contrast, the ionic conductivity of the pellets from alumina crucibles is about 1.81 × 10(-4) S cm(-1) and drops to 2.39 × 10(-5) S cm(-1) 3 months later. The large grains and the reduced grain boundaries in the pellets sintered in Pt crucibles are favorable to obtain high ionic conductivity and good air stability. X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy results suggest that the formation of Li2CO3 on the pellet surface is probably another main reason, which is also closely related to the relative density and the amount of grain boundary within the pellets. This work stresses the importance of synthesis parameters, crucibles included, to obtain the LLZO electrolyte with high ionic conductivity and good air stability.

The effect of annealing on a 3D SnO2/graphene foam as an advanced lithium-ion battery anode.

3D annealed SnO2/graphene sheet foams (ASGFs) are synthesized by in situ self-assembly of graphene sheets prepared by mild chemical reduction. L-ascorbyl acid is used to effectively reduce the SnO2 nanoparticles/graphene oxide colloidal solution and form the 3D conductive graphene networks. The annealing treatment contributes to the formation of the Sn-O-C bonds between the SnO2 nanoparticles and the reduced graphene sheets, which improves the electrochemical performance of the foams. The ASGF has features of typical aerogels: low density (about 19 mg cm(-3)), smooth surface and porous structure. The ASGF anodes exhibit good specific capacity, excellent cycling stability and superior rate capability. The first reversible specific capacity is as high as 984.2 mAh g(-1) at a specific current of 200 mA g(-1). Even at the high specific current of 1000 mA g(-1) after 150 cycles, the reversible specific capacity of ASGF is still as high as 533.7 mAh g(-1), about twice as much as that of SGF (297.6 mAh g(-1)) after the same test. This synthesis method can be scaled up to prepare other metal oxides particles/ graphene sheet foams for high performance lithium-ion batteries, supercapacitors, and catalysts, etc.

Facile synthesis of V(4+) self-doped, [010] oriented BiVO4 nanorods with highly efficient visible light-induced photocatalytic activity.

Monodispersed monoclinic BiVO4 nanorods grown along the [010] direction were prepared using a one-step low temperature hydrothermal method in the presence of the low-cost, nontoxic sodium oleate serving as a chelating agent. The BiVO4 nanorods with diameters of 15-20 nm possess a huge specific surface area as large as 28.2 m(2) g(-1), which can endow them with high photocatalytic activity and strong adsorption of reactants. Meanwhile, the specific [010] growth direction is capable of facilitating efficient electron-hole separation by accumulating electrons on {010} facets. Thus, the highly efficient photocatalytic activity of the as-prepared BiVO4 nanorods under visible light, which far surpasses that of commercial P25, is demonstrated by the degradation of rhodamine B and phenol. Plentiful V(4+) species, which can create oxygen vacancies, is detected implying that the as-obtained nanorods are self-doped BiVO4. Significantly, 61% of rhodamine B is adsorbed by the BiVO4 nanorods before irradiation owing to the appearance of plentiful O(2-) and OH(-) species on the surface adsorbed by oxygen vacancies. More excitingly, the excellent visible-light-driven photocatalytic activity of the as-obtained BiVO4 nanorods can be further elevated to an unprecedented level, roughly doubled, after applying a low temperature heat treatment process at 230 °C for 2 h and this improvement could primarily be ascribed to their optimized charge-carrier transport characteristics resulting from elevated crystallinity and decreased V(4+) species.

Fabrication of free-standing Cu nanorod arrays on Cu disc by template-assisted electrodeposition.

Free-standing Cu nanorod arrays on Cu foil have been fabricated by a template-assisted method. Cu nanorods were potentiostatically deposited on mechanically polished Cu foil using anodized aluminum oxide templates as the deposition mask. Three electrolyte systems were compared, including two acid copper sulfate based solutions and one alkaline solution. The most uniform nanorods were achieved in the alkaline electrolyte. The weight gain per unit area after electrodeposition has been used as a direct measure of average length of deposited Cu nanorods. It was found that our control over the uniformity in nanorod length across the array is important in reaching the maximized aspect ratio without aggregation. Through controlling the weight change it was possible to control the aspect ratio of nanorods and to avoid aggregation of nanorods. Our capability to fabricate free-standing Cu nanorod arrays of uniform height with maximized aspect ratio on Cu foil is especially important in applying this nanostructured Cu as a current collector in Li ion batteries.