Yang Li

Jiangsu University, Chenkiang, Jiangsu Sheng, China

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Publications (10)27.89 Total impact

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    ABSTRACT: In this work, bifunctional TiO2/Ag3PO4/graphene (GR) composites have been prepared via the combination of ion-exchange method and hydrothermal approach, and the fabrication of “pizza-like” three-phase TiO2/Ag3PO4/GR composites has been achieved through the electrostatic-driven assembly of positively-charged Ag+ on negatively-charged graphene oxide (GO) sheets, followed by the nucleation & controlled growth of Ag3PO4 and the deposition of Degussa P25 on the GO surface. Consequently, the hydrothermal treatment leads to the generation of TiO2/Ag3PO4/GR composites with well-defined structures. The as-prepared composites exhibited highly efficient visible light photocatalytic activity toward organic dye molecule degradation and showed excellent bactericidal performance. This is the first report on the production of bifunctional three-phase metal oxide-Ag3PO4-GR composite materials with improved photocatalytic and antibacterial properties. The improved photocatalytic activity is attributed to the effective separation of photoexcited electron-hole pairs and fast charge transfer between components in the composite, while its excellent bactericidal performance is believed to come from intrinsic bacterial inactivation of Ag3PO4 and photo-induced antibacterial activity of active oxygen-containing radicals generated in the irradiated system. The proper molar ratio of Ag3PO4/TiO2 and the added amount of GO in the precursor have been considered to play crucial roles in the formation of bifunctional composites with promising properties. The TiO2/Ag3PO4/GR composite significantly decreases the percentage of expensive Ag-containing material while it reveals better photocatalytic and antibacterial performance than Ag3PO4, providing new insights into the low-cost, large-scale production of Ag3PO4-based function materials for practical applications.
    RSC Advances 01/2014; 4(36):18627. DOI:10.1039/c4ra01559b · 3.71 Impact Factor
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    ABSTRACT: Graphene (GR)-TiO2 mesocrystal composites were prepared by a facile template-free process based on the combination of sol-gel and solvothermal methods, and were characterized using field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), Raman spectroscopy, UV-vis diffuse reflectance spectroscopy (UV-vis DRS), nitrogen absorption and electron spin resonance (ESR). Visible light photocatalytic performance of GR-TiO2 composites was evaluated for photocatalytic degradation of organic dye Rhodamine B. It was found that the amount of graphene oxide (GO) added obviously affects morphologies of TiO2 mesocrystals and photocatalytic activities of as-prepared nanocomposites. Composites prepared in the presence of different amounts of GO all exhibit higher photocatalytic activity than pure TiO2 mesocrystals and P25, the composite obtained by using 20mg GO presents the most uniform TiO2 mesocrystals in the composite and shows the highest photocatalytic efficiency. The mechanism for the generation of TiO2 mesocrystals in the GR-TiO2 composite is proposed and possible reasons for the enhancement in visible light photocatalytic efficiency are also discussed.
    Journal of hazardous materials 07/2013; 261C:342-350. DOI:10.1016/j.jhazmat.2013.07.044 · 4.33 Impact Factor
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    ABSTRACT: Alopecia areata (AA) is a non-scarring inflammatory hair loss disease. We investigated the early pathological changes of AA to identify possible factors participating in its pathogenesis. Clinical, laboratory and pathological features of 87 AA patients were investigated. Anti-nuclear antibody was found in 11 of 85 patients tested (13%), with a higher percentage in women (21%) than men (5%) (P = 0.026). In early AA lesions, inflammatory infiltration in the upper dermis and epithelial cell damage of the hair follicle infundibulum, just above the sebaceous gland, was observed. Liquefaction and disarrangement of peripheral infundibular epithelial cells coexisted with T-lymphocytic invasion and regression of the lower follicle. The latter findings positively correlated with the presence of eosinophils and perivascular mononuclear cell infiltration in the upper dermis. Eosinophilic infiltration was found in 35 patients (40%) and was positively correlated to elevated serum IgE levels (r = 0.21, P = 0.044), a more severe perivascular lymphocytic inflammation in the upper dermis (r = 0.24, P = 0.026), as well as a prominent swarm of bees-like peri-follicular infiltration (r = 0.41, P < 0.001). Mast cells were abundant in the upper dermis, especially around blood vessels, and positively correlated with eosinophil presence (r = 0.30, P = 0.027). Damage to the hair follicle infundibulum in the upper dermis might be an important component of early changes in AA lesions, possibly caused by lymphocyte cell infiltration in the same area. AA may involve damage of the upper hair follicle as well as the bulb, possibly involving hypersensitivity and autoimmunity.
    Australasian Journal of Dermatology 06/2013; 54(3). DOI:10.1111/ajd.12065 · 0.98 Impact Factor
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    ABSTRACT: A facile and effective hydrothermal method for the fabrication of the Ag3PO4-graphene (Ag3PO4-GR) visible light photocatalyst has been developed to improve the photocatalytic performance and stability of Ag3PO4, and also to reduce the high cost of Ag3PO4 for practical uses. The size and morphology of Ag3PO4 particles could be tailored by the electrostatically driven assembly of Ag+ on graphene oxide (GO) sheets and by the controlled growth of Ag3PO4 particles on the GO surface. The generation of Ag3PO4 and the transformation of GO to GR can be achieved simultaneously in the hydrothermal process. The improved photocatalytic activity of Ag3PO4-GR composites under visible light irradiation is attributed to high-surface-area GR sheets, enhanced absorption of organic dyes, and more efficient separation of photogenerated electron–hole pairs. The transfer of photogenerated electrons from the surface of Ag3PO4 to GR sheets also reduces the possibility of decomposing Ag+ to metallic Ag, suggesting an improved stability of recyclable Ag3PO4-GR composite photocatalyst. Moreover, with the advances in the large-scale production of high-quality GO, the use of GO as the starting material can also reduce the cost for the synthesis of Ag3PO4-based photocatalysts without weakening their photocatalytic activities.
    ACS Catalysis 02/2013; 3(3):363–369. DOI:10.1021/cs3008126 · 7.57 Impact Factor
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    ABSTRACT: Graphene oxide (GO)-enwrapped Ag3PO4 composites were successfully fabricated by the electrostatically-driven assembly of positively charged silver ions on the negatively charged GO sheets, followed by the controlled growth of sphere-like Ag3PO4 particles on GO sheets via an in-situ ion-exchange method. Moreover, GO–Ag3PO4 composites were fully characterized and the visible light photocatalytic performance of the GO–Ag3PO4 sample was investigated. The results indicated that the presence of GO sheets could effectively tailor the size of Ag3PO4 particles, GO–Ag3PO4 composites exhibited excellent visible-light absorption, and the photocatalytic degradation efficiency of Rhodamine B (RhB) over GO–Ag3PO4 composites is apparently higher than with pure Ag3PO4 mainly due to the photo-induced holes and the generation of irradiated active superoxide radicals.
    Materials Letters 02/2013; 93:28–31. DOI:10.1016/j.matlet.2012.10.116 · 2.27 Impact Factor
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    ABSTRACT: Rod-like nanosized silver tungstate (Ag2WO4) was synthesised via a facile hydrothermal method and characterised by field emission scanning electron microscopy, X-ray diffraction, Raman spectroscopy and electron spin resonance spectroscopy. Under ultraviolet (UV) light, nearly complete degradation of rhodamine B (RhB) was observed in Ag2WO4 suspension after irradiation for 60 min, around 15 RhB was absorbed in the dark. However, more than 60 of methyl blue was absorbed in the dark and the rest was observed to be completely degraded upon UV light irradiation for 10 min. The formed superoxide (O2-.) and hydroxyl (·OH) radicals, as well as photoinduced holes were considered to be the dominant active species in the photocatalytic process.
    Micro & Nano Letters 12/2012; 7(12):1285-1288. DOI:10.1049/mnl.2012.0765 · 0.80 Impact Factor
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    ABSTRACT: In this study, an amino acid, glutamine, has been employed as the modifier in the hydrothermal synthesis of rod-like hydroxyapatite (HAp) nanoparticles. X-ray diffractometer results confirm the formation of a typical HAp phase without impurities and microscopic results indicate that the morphology and size of the as-prepared products could be controlled by adjusting the pH value of the hydrothermal system. Owing to a variety of amino acids and characteristics of as-synthesised nano-sized HAp, the findings may have implications in the large-scale controllable synthesis of well-defined HAp nanomaterials; it may also provide a general facile and low-cost method for the preparation of uniform nanostructured HAp by utilising biomolecules as modifiers.
    Micro & Nano Letters 12/2012; 7(12):1292-1295. DOI:10.1049/mnl.2012.0674 · 0.80 Impact Factor
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    ABSTRACT: The tribological behavior of graphene oxide (GO) films deposited on a mica substrate has been investigated by atomic force microscopy, in which different voltages were applied to a tip. It was found that the frictional forces on the GO films remain unchanged in the presence of negative tip voltages, while the frictional forces increase remarkably with an increase of the voltage when positive voltages are given to the tip, and at a certain positive tip voltage the frictional forces reach a stable value with increasing number of repeated cycles. To study the influence of the tip voltage on the frictional forces of the GO films, the adhesive and electrostatic force gradients between the tip and GO films were measured. The results showed that the adhesive and electrostatic forces increased with increase of the positive tip voltages. This phenomenon is due to the polarization of charges in the GO films induced by the applied tip voltages, which causes intensive electrostatic interactions between the tip and GO films and a corresponding rise in the adhesive forces and the frictional forces.
    Nanotechnology 11/2012; 23(49):495703. DOI:10.1088/0957-4484/23/49/495703 · 3.67 Impact Factor
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    ABSTRACT: Background: Mechanism leading to an abrupt hair loss in diffuse alopecia areata (AA) remains unclear. Aims: To explore the characteristics of diffuse AA and possible factors involved in its pathogenesis. Methods: Clinical and laboratory data of 17 diffuse AA patients and 37 patchy AA patients were analyzed retrospectively. Serum IgE level was evaluated in all diffuse and patchy AA patients, as well as 27 healthy subjects without hair loss to serve as normal control. Univariate analysis was performed using Fisher's exact test and Wilcoxon rank-sum test. Associations between inflammatory cell infiltration and laboratory values were analyzed using Spearman rank correlation test. Results: The mean age of patients with diffuse AA was 27 years with a mean disease duration of 1.77 months. All of them presented in spring or summer with an acute onset of diffuse hair loss preceded by higher incidence of scalp pruritus. Although no statistically significant difference on the incidence of atopic disease among three groups has been found, serum IgE level in diffuse AA was higher than that in healthy controls, but was comparable to that in patchy AA group. Histopathology of lesional scalp biopsies showed more intense infiltration comprising of mononuclear cells, eosinophils, CD3 + , and CD8 + T cells around hair bulbs in diffuse AA group than in patchy AA group. Moreover, IgE level in diffuse AA patients positively correlated with intensity of infiltration by mononuclear cells, eosinophils, and CD8 + T cells. Conclusions: Hypersensitivity may be involved in pathogenesis of diffuse AA. The acute onset of diffuse AA may be related to intense local inflammatory infiltration of hair loss region and an increase in serum IgE level.
    Indian journal of dermatology, venereology and leprology 11/2012; 78(6):709-14. DOI:10.4103/0378-6323.102361 · 1.33 Impact Factor
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    ABSTRACT: Henoch-Schönlein purpura (HSP) is a small-vessel vasculitis mediated by IgA-immune complex deposition. It is characterized by the clinical tetrad of non-thrombocytopenic palpable purpura, abdominal pain, arthritis and renal involvement. The diagnosis of HSP is difficult, especially when abdominal symptoms precede cutaneous lesions. We report a rare case of paroxysmal drastic abdominal pain with gastrointestinal bleeding presented in HSP. The diagnosis was verified by renal damage and the occurrence of purpura.
    World Journal of Gastroenterology 04/2012; 18(16):1991-5. DOI:10.3748/wjg.v18.i16.1991 · 2.43 Impact Factor