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1.
J Colloid Interface Sci ; 565: 218-226, 2020 Apr 01.
Article in English | MEDLINE | ID: mdl-31972335

ABSTRACT

Highly conductive cathode material with enhanced Na+ diffusion kinetics is of great importance in the exploration of sodium ion batteries. In this work, Na0.91MnO2 porous microcube which is coated with highly conductive polypyrrole (PPy) is obtained. The high Na content in the layered sodium manganate oxide brings about wider interlayer distance resulting in high capacity and electrochemical kinetics. The higher sodium content of Na0.91MO2 makes capacity increase up to 50 mAh g-1 compared with Na0.7MnO2.05. Furthermore, the well-designed combination between porous structure and conductive PPy coating exhibits fast ion/electron transfer inside the electrode and high cycling stability. The PPy coated Na0.91MnO2 delivers a high initial capacity of 208 mAh g-1, encouraging capacity retention and rate capability. Based on the porous Na0.91MnO2@PPy cathode, the sodium ion full cells with puffed millet porous carbon anode show remarkably stable cycling and high-rate performances.

2.
J Colloid Interface Sci ; 560: 169-176, 2020 Feb 15.
Article in English | MEDLINE | ID: mdl-31670014

ABSTRACT

Tin oxide (SnO2) has been widely used as an anode material for sodium-ion storage because of its high theoretical capacity. However, it suffers from large volume expansion and poor conductivity. To overcome these limitations, in this study, we have designed and prepared Mo-doped SnO2 nanoflake arrays anchored on carbon foam (Mo-SnO2@C-foam with 38.41 wt% SnO2 and 3.7 wt% Mo content) by a facile hydrothermal method. The carbon foam serves as a three-dimensional conductive network and a buffer skeleton, contributing to improved rate performance and cycling stability. In addition, Mo doping enhances the kinetics of sodium-ion transfer, and the interlaced SnO2 nanoflake arrays is beneficial to promote the conversion reactions during the charge/discharge process. The as-prepared composite with a unique structure demonstrate a high initial capacity of 1017.1 mAh g-1 at 0.1 A g-1, with a capacity retention over three times higher than that of the control sample (SnO2@C-foam) at 1 A g-1, indicating a remarkable rate performance.

3.
J Colloid Interface Sci ; 551: 219-226, 2019 Sep 01.
Article in English | MEDLINE | ID: mdl-31078977

ABSTRACT

Improving the insulating nature of sulfur and retaining the soluble polysulfides in sulfur cathodes are crucial for realizing the practical application of lithium-sulfur batteries (LSBs). Biomass-based carbon is becoming increasingly popular for fabricating economical and efficient cathodes for LSBs owing to its unique structure. Herein, we report a facile strategy to transform bovine bone with an organic-inorganic structure into cellular hierarchical porous carbon via carbonization and KOH activation, followed by CoS2 modification through hydrothermal treatment. The synthesized composite can load abundant sulfur and produce a dual effect of "physical confinement and chemical entrapment" on polysulfides. The conductive carbon frame with the developed porous structure provides adequate space to accommodate sulfur and physically suppress the shuttle effect of polysulfides. The embedded half-metallic CoS2 sites can chemically anchor the polysulfides and enhance the electrochemical reaction activity as well. Owing to the multifunctional structure and dual restraint effect, the designed electrode exhibits enhanced electrochemical properties including high initial capacity (1230.9 mAh g-1 at 0.2 C), improved cycling stability and enhanced rate capability.


Subject(s)
Bone and Bones/chemistry , Carbon/chemistry , Cobalt/chemistry , Electric Power Supplies , Lithium , Animals , Biological Products/chemistry , Cattle , Electric Conductivity , Electrochemical Techniques/methods , Electrodes , Lithium/chemistry , Minerals/chemistry , Molecular Structure , Porosity , Sulfides/chemistry
4.
J Colloid Interface Sci ; 535: 300-307, 2019 Feb 01.
Article in English | MEDLINE | ID: mdl-30316116

ABSTRACT

Exploring high performance cathode materials is of great means for the development of bi-functional electrochromic energy storage devices. Herein, Nb-doped WO3 mesoporous films as integrated high-quality cathode are successfully constructed via a facile sol-gel method. Chemical state and crystallinity of the WO3 based films are significantly influenced by doping concentration. Compared with the pure WO3, the optimal Nb-doped film shows improved optical-electrochemical properties with high specific capacity (74.4 mAh g-1 at 2 A g-1), excellent high-rate capability, large optical contrast (61.7% at 633 nm), and ultra-fast switching speed (3.6 s and 2.1 s for coloring and bleaching process, respectively). These positive features suggest the potential application of Nb-doped WO3 mesoporous cathode. Our research paves the way for the development of multifunctional photoelectrochemical energy devices.

5.
ACS Appl Mater Interfaces ; 10(28): 24209-24216, 2018 Jul 18.
Article in English | MEDLINE | ID: mdl-29939715

ABSTRACT

Deep eutectic solvents (DESs) are, at room temperature, about dozens to hundreds of times more viscous than water, which brings pretty thick residues on solid surfaces, for example, causing drag-out and weight loss in the transfer process. Unfortunately, until now little work had been done for solving this knotty problem. In this study, the super antiwetting surface, i.e., super-DES-phobic surface (defined as DES contact angle > 150°) is proposed and fabricated successfully by a facile coating technique. Hierarchical silver dendrites on copper foam substrate provide effective dual-roughness surfaces showing stable superDESphobicity. The superDESphobic surface can repel the DESs and their derived solutions even under elevated temperature of about 120 °C and the impact attack of drops. It is also found that the superDESphobic surface can significantly delay the DESs freezing and reduce the adhesion strength of the frozen DESs. Interestingly, the superDESphobic surface can be applied as an effective tool for gauging the density of DES using an ∼2 µL droplet in virtue of its super antiwetting property. The super antiwetting surfaces show promise for potential applications in DES self-cleaning and antifreezing.

6.
J Colloid Interface Sci ; 465: 112-20, 2016 Mar 01.
Article in English | MEDLINE | ID: mdl-26669497

ABSTRACT

Metal-doping is considered to be an effective way for construction of advanced semiconducting metal oxides with tailored physicochemical properties. Herein, Mo-doped WO3 nanowire arrays are rationally fabricated by a sulfate-assisted hydrothermal method. Compared to the pure WO3, the optimized Mo-doped WO3 nanowire arrays exhibit improved electrochromic properties with fast switching speed (3.2s and 2.6s for coloration and bleaching, respectively), significant optical modulation (56.7% at 750nm, 83.0% at 1600nm and 48.5% at 10µm), high coloration efficiency (123.5cm(2)C(-1)) and excellent cycling stability. In addition, as a proof of concept, the Mo-doped WO3 nanowire arrays are demonstrated with electrochemical energy storage monitored by the electrochromism. This electrode design protocol can provide an alternative way for developing high-performance active materials for bi-functional electrochromic batteries.

7.
J Colloid Interface Sci ; 460: 200-8, 2015 Dec 15.
Article in English | MEDLINE | ID: mdl-26321573

ABSTRACT

High-performance electrochromic films with large color contrast and fast switching speed are of great importance for developing advanced smart windows. In this work, crystalline/amorphous WO3 core/shell (c-WO3@a-WO3) nanowire arrays rationally are synthesized by combining hydrothermal and electrodeposition methods. The 1D c-WO3@a-WO3 core/shell hierarchical structures show a synergistic effect for the enhancement of optical modulation, especially in the infrared (IR) region. By optimizing the electrodeposition time of 400s, the core/shell array exhibits a significant optical modulation (70.3% at 750nm, 42.0% at 2000nm and 51.4% at 10µm), fast switching speed (3.5s and 4.8s), high coloration efficiency (43.2cm(2)C(-1) at 750nm) and excellent cycling performance (68.5% after 3000 cycles). The crystalline/amorphous nanostructured film can provide an alternative way for developing high-performance electrochromic materials.

8.
J Colloid Interface Sci ; 454: 134-43, 2015 Sep 15.
Article in English | MEDLINE | ID: mdl-26005799

ABSTRACT

Adsorption is often time consuming due to slow diffusion kinetic. Sizing he adsorbent down might help to accelerate adsorption. For CoFe spinel oxide, a magnetically separable adsorbent, the preparation of nanosheets faces many challenges including phase separation, grain growth and difficulty in preparing two-dimensional materials. In this work, we prepared porous CoFe oxide nanosheet with chemical formula of Co2.698Fe0.302O4 through topochemical transformation of a CoFe precursor, which has a layered double hydroxide (LDH) analogue structure and a large interlayer spacing. The LDH precursor was synthesized from a cheap deep eutectic solvent (DES) system. The calcined Co2.698Fe0.302O4 has small grain size (10-20nm), nanosheet morphology, and porous structure, which contribute to a large specific surface area of 79.5m(2)g(-1). The Co2.698Fe0.302O4 nanosheets show fast removal ability and good adsorption capacity for both organic waste (305mgg(-1) in 5min for Congo red) and toxic heavy metal ion (5.27mgg(-1) in 30min for Cr (VI)). Furthermore, the Co2.698Fe0.302O4 can be separated magnetically. Considering the precursor can be prepared through a fast, simple, surfactant-free and high-yield synthetic strategy, this work should have practical significance in fabricating adsorbents.

9.
J Colloid Interface Sci ; 438: 149-158, 2015 Jan 15.
Article in English | MEDLINE | ID: mdl-25454437

ABSTRACT

Manganese oxides with desired structure are controllably obtained through annealing MnCO3 precursors with required structures. The structures of MnCO3 precursors are determined by a "mesocrystal formation" process in an ionic liquid system of a choline chloride/urea (CU) mixture. Without addition of surfactants, only CU solvent and manganese chloride are needed in the reaction system, in which the CU acts as reaction medium as well as control agent for particle growth. A shape transformation of MnCO3 particles from well-defined rhombohedral mesocrystals to ellipsoidal polycrystal ensembles, and to nanoparticulate aggregates is observed when heating the reaction system for 4 h at 120, 150, and 180 °C, respectively. With a longer aging time at 120 °C, etching and disassembly of MnCO3 mesocrystals happened. The correlation between the microstructure and the underlying formation mechanism is highlighted. Porous and nanowire-like MnO(x) nanostructures are obtained through a facile thermal conversion process from the diverse MnCO3 precursors, which are demonstrated as effective and efficient adsorbents to remove organic waste (e.g. Congo red) from water. Significantly, the nanowire-like MnO(x) nanostructures obtained by annealing the MnCO3 mesocrystals at 300 °C for 4 h can remove about 95% Congo red in waste water at room temperature in only one minute, which is superior to the reported hierarchical hollow nanostructured MnO2.

10.
Chem Commun (Camb) ; 51(6): 1004-7, 2015 Jan 21.
Article in English | MEDLINE | ID: mdl-25358246

ABSTRACT

The traditional concept that nickel layered double hydroxide (Ni LDH, also known as α-Ni(OH)2) converts to NiO after annealing has been taken without doubt and utilized to fabricate NiO for years. This work reports that an anomalous self-reduction phenomenon can occur for Ni LDH synthesized from an ionic liquid system.

12.
Jpn J Thorac Cardiovasc Surg ; 49(9): 545-51, 2001 Sep.
Article in English | MEDLINE | ID: mdl-11577444

ABSTRACT

OBJECTIVES: Recent advances in molecular biology and genetics have created new diagnostic and treatment possibilities in clinical oncology. We evaluated the usefulness of molecular biological factors in primary tumor and micrometastasis in the bone marrow and pathological negative (pN0) lymph nodes as prognostic parameters in non-small-cell lung cancer (NSCLC) patients. METHODS: Pathological specimens were collected from 129 NSCLC patients to analyze molecular biological markers, including K-ras, p53, Rb, p16, loss of heterozygosity (LOH) at 3p, vascular endothelial growth factor (VEGF), and telomerase activity. Bone marrow samples from 250 NSCLC patients and pN0 lymph nodes from 85 of these patients were collected for micrometastasis detection by immunohistochemistry against cytokeratin. RESULTS: p53 abnormalities and 3p LOH were significantly associated with reduced patient survival in adenocarcinoma, whereas VEGF expression was significantly associated with reduced survival in a squamous cell carcinoma histological subtype by univariate or multivariate analysis. We identified micrometastatic tumor cells in bone marrow of 78 (31.2%) of 250 patients and in pN0 lymph nodes of 26 (30.6%) of 85 patients. Both bone marrow and lymph nodal micrometastases were associated with decreased survival among patients with stage I, however, only lymph nodal micrometastasis had a significant impact on survival. CONCLUSIONS: Molecular biological features of primary tumor and micrometastatic status appear useful in defining groups of patients with a poor prognosis who could benefit from adjuvant systemic treatment.


Subject(s)
Biomarkers/analysis , Carcinoma, Non-Small-Cell Lung/mortality , Lung Neoplasms/mortality , Neoplasm Metastasis , Adult , Aged , Aged, 80 and over , Bone Marrow/pathology , Female , Humans , Loss of Heterozygosity , Lymph Nodes/pathology , Male , Middle Aged
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