The Experts below are selected from a list of 1545 Experts worldwide ranked by ideXlab platform
Ai-jun Wang - One of the best experts on this subject based on the ideXlab platform.
-
flower like platinum cobalt ruthenium alloy nanoassemblies as robust and highly efficient electrocatalyst for hydrogen evolution reaction
Journal of Colloid and Interface Science, 2020Co-Authors: Hongyan Chen, Jiu-ju Feng, Huajie Niu, Xuexiang Weng, Hong Huang, Ai-jun WangAbstract:Abstract Exploring hydrogen evolution reaction (HER) catalyst with highly catalytic features in alkaline conditions is considered as significance for water splitting. In this study, a general and simple method was developed to prepare flower-like platinum-cobalt-ruthenium alloy nanoassemblies (PtCoRu NAs) by using murexide and Cetyltrimethylammonium Chloride (CTAC) as the co-structure-directing agents. Benefiting from the structural advantages and multimetallic compositions, the as-prepared PtCoRu NAs displayed remarkably enhanced electrocatalytic performance for the HER in 1.0 M KOH, with a low overpotential (η, 22 mV) to drive 10 mA cm−2, small Tafel slope (46 mV dec−1), and high exchange current density (j0, 3.30 mA cm−2) during the long-term electrolysis. The as-developed strategy sheds some valuable guidelines for preparing advanced multimetallic catalysts for production of hydrogen in fuel cells.
-
one pot solvothermal synthesis of three dimensional hollow ptcu alloyed dodecahedron nanoframes with excellent electrocatalytic performances for hydrogen evolution and oxygen reduction
Journal of Colloid and Interface Science, 2019Co-Authors: Hongyan Chen, Jiu-ju Feng, Qianli Zhang, Ai-jun WangAbstract:Abstract It is a great challenge to develop simple approach to construct three-dimensional (3D) bimetallic alloyed nanoframes (NFs) with tunable surface structures, albeit with the availability of noble metal NFs in catalysis. Herein, a one-pot solvothermal method was employed for scalable preparation of uniform hollow PtCu rhombic dodecahedron nanoframes (PtCu RDNFs) in the presence of Cetyltrimethylammonium Chloride (CTAC), where diglycolamine (DGA) served as the co-reductant and co-structure director. The above architectures had the larger electrochemically active surface area (ECSA, 36.85 m2 g−1Pt) than that of commercial Pt black (15.85 m2 g−1Pt), along with the improved catalytic characters for hydrogen evolution reaction (HER) and oxygen reduction reaction (ORR) in acid electrolytes alternative to those of Pt black. It demonstrates great potential applications of PtCu RDNFs in fuel cells and beyond.
-
a novel electrochemical immunosensor for highly sensitive detection of prostate specific antigen using 3d open structured ptcu nanoframes for signal amplification
Biosensors and Bioelectronics, 2019Co-Authors: Yao Chen, Ai-jun Wang, Lu Zhang, Peixin Yuan, Xiliang Luo, Yadong Xue, Jiu-ju FengAbstract:Abstract Herein, a novel electrochemical ultrasensitive immunosensor was designed for detecting prostate-specific antigen (PSA) with three-dimensional (3D) PtCu hollow nanoframes (PtCu HNFs) as signal amplification. The highly opened PtCu HNFs were synthesized by a one-pot solvothermal method with Cetyltrimethylammonium Chloride (CTAC) and trishydroxymethyl aminomethane (Tris) as co-structuring directors. The architectures enlarged the loading of prostate specific antibodies (Ab) and efficiently catalyzed hydrogen peroxide (H2O2) reaction, ultimately amplifying the signals. And polylysine was used to disperse PtCu HNFs, improve the biocompatibility and bind the Ab on the electrode surface. The fabricated immunosensor exhibited lower detection limit (0.003 ng mL–1, S/N = 3), and wider linear range (0.01–100.0 ng mL–1), along with the improved reproducibility, selectivity and stability for the assay of PSA. Thus, it is a desirable platform for PSA detection in clinical diagnosis and practical applications.
-
One-Step Synthesis of PtCu Alloyed Nanocages with Highly Open Structures as Bifunctional Electrocatalysts for Oxygen Reduction and Polyhydric Alcohol Oxidation
2018Co-Authors: Xian-yan Huang, Ai-jun Wang, Xiao-fang Zhang, Lu Zhang, Jiu-ju FengAbstract:Three-dimensional (3D) bimetallic PtCu alloyed nanocages (NCs) with highly open structures and large external- and internal-surfaces accessible for reactants were facilely synthesized by a one-pot solvothermal method. Arginine and Cetyltrimethylammonium Chloride (CTAC) acted as the costructure-directors and stabilizing agents. The resultant PtCu NCs showed significantly enhanced catalytic activity and improved stability when compared to commercial Pt/C (50 wt %) and Pt black catalysts toward oxygen reduction reaction (ORR), ethylene glycol oxidation reaction (EGOR), and glycerol oxidation reaction (GOR) in alkaline electrolyte. This work provides guidelines for rational synthesis of highly open cagelike architectures
-
Solvothermal Synthesis of Monodisperse PtCu Dodecahedral Nanoframes with Enhanced Catalytic Activity and Durability for Hydrogen Evolution Reaction
2018Co-Authors: Xiao-fang Zhang, Ai-jun Wang, Lu Zhang, Junhua Yuan, Jiu-ju FengAbstract:Nanoframes (NFs) with highly open structures have attracted substantial attention because of their large surface area, three-dimensional structure and good stability, which are of significance to enhance the catalytic characters. However, it is still challenging to develop facile and efficient method to construct Pt-based NFs with tailored structures. Herein, a simple solvothermal method was developed to prepare monodisperse PtCu dodecahedral nanoframes (PtCu DNFs), where Cetyltrimethylammonium Chloride (CTAC) served as the structure-director and dispersing agent, oleylamine as reductant, allantoin as the co-structure-director and coreductant. The PtCu DNFs displayed remarkably improved catalytic performances for hydrogen evolution reaction (HER) in both acid and alkaline electrolytes relative to homemade PtCu nanopolyhedrons (NPHs), commercial Pt/C (20 wt%) and Pt black catalysts. The work offers some instructive guidelines for synthesis of novel metallic NFs as efficient HER catalysts
Shin-ichi Wakida - One of the best experts on this subject based on the ideXlab platform.
-
simultaneous determination of iodide and iodate in seawater by transient isotachophoresis capillary zone electrophoresis with artificial seawater as the background electrolyte
Journal of Chromatography A, 2004Co-Authors: Kuriko Yokota, Sahori Takeda, Keiichi Fukushi, Shin-ichi WakidaAbstract:We developed capillary zone electrophoresis with transient isotachophoresis (ITP) as an on-line concentration procedure for simultaneous determination of iodide and iodate in seawater. The effective mobility of iodide was decreased by addition of 20 mM Cetyltrimethylammonium Chloride to an artificial seawater background electrolyte so that transient ITP functioned for both iodide and iodate. Limits of detection for iodide and iodate were 4.0 and 5.0 μg/l (as iodine) at a signal-to-noise ratio of 3. Values of the relative standard deviation of peak area, peak height, and migration times for iodide and iodate were 2.9, 1.3, 1.0 and 2.3, 2.1, 1.0%, respectively. The proposed method was applied to simultaneous determination of iodide and iodate in seawater collected at a pond at our university.
-
Development of a novel running buffer for the simultaneous determination of nitrate and nitrite in human serum by capillary zone electrophoresis.
Journal of chromatography. A, 2003Co-Authors: Takashi Miyado, Hidenori Nagai, Sahori Takeda, Keiitsu Saito, Keiichi Fukushi, Yasukazu Yoshida, Shin-ichi Wakida, Etsuo NikiAbstract:In order to improve NO2- peak height and obtain a convenient buffer system for the assay of nitrogen monooxide metabolites, we developed a novel running buffer for the simultaneous determination of nitrite and nitrate in human serum by capillary electrophoresis. The addition of Cetyltrimethylammonium Chloride to the running buffer resulted in high-speed separation using reverse electroosmotic flow. Highly sensitive determination was also achieved using stacking with 10-fold diluted sample solutions. The samples were injected hydrodynamically for 100 s into a 50 cm x 75 microm I.D. capillary. The separation voltage was 10 kV (negative polarity). UV detection was performed at 214 nm. We obtained complete separation of nitrite and nitrate in deproteinized human serum within 6 min with optimum analytical conditions. Linear calibration curves for nitrite and nitrate for both peak height and peak area were obtained with standard addition method. The limits of detection obtained at a signal-to-noise ratio of 3 for nitrite and nitrate were 4.1 and 2.0 microM, while the values of relative standard deviation of peak height were 2.4 and 2.6%, respectively.
-
capillary zone electrophoretic determination of iodide in seawater using transient isotachophoresis with artificial seawater as the background electrolyte
Electrophoresis, 2003Co-Authors: Kuriko Yokota, Sahori Takeda, Keiichi Fukushi, Nobuhiro Ishio, Nobukazu Sasayama, Yusuke Nakayama, Shin-ichi WakidaAbstract:We describe an application of capillary zone electrophoresis (CZE) with transient isotachophoresis (ITP) as the on-line concentration procedure for the determination of iodide in seawater. The effective mobility of iodide was decreased by the addition of 10 mM Cetyltrimethylammonium Chloride (CTAC) to an artificial seawater background electrolyte (BGE) so that transient ITP functioned and iodide was separated from other coexisting anions such as bromide, nitrite, and nitrate in seawater samples. After sample injection, 600 mM acetate was separately injected into the capillary as the terminating ion to generate transient ITP. The limit of detection (LOD) for iodide was 3.0 microg/L. The LOD was obtained at a signal-to-noise ratio (S/N) of 3. The values of the relative standard deviation (RSD) of peak area, peak height, and migration time for iodide were 2.9, 2.1, and 0.6%. The proposed method was applied to the determination of iodide in seawater collected around the Osaka Bay. The results obtained by use of the calibration graph were agreed with those obtained by the addition of the standard solutions for iodide.
-
determination of nitrite and nitrate in a proposed certified reference material for nutrients in seawater by capillary zone electrophoresis with artificial seawater as the background electrolyte using transient isotachophoresis
Electrophoresis, 2002Co-Authors: Keiichi Fukushi, Takashi Miyado, Sahori Takeda, Keiitsu Saito, Nobuhiro Ishio, Hideaki Nishio, Shin-ichi WakidaAbstract:We describe a combination of selected ions as a terminating ion which is useful for transient isotachophoresis (ITP) in capillary zone electrophoresis (CZE) for the determination of nitrite and nitrate in seawater. In addition to 150 mM sulfate as the principal terminating ion, 10 mM bromate was added to a sample solution as the additional terminating ion. Artificial seawater containing 3 mM Cetyltrimethylammonium Chloride (CTAC) was adopted as a background electrolyte (BGE). The limits of detection (LODs) for nitrite and nitrate were 2.2 and 1.0 microg/L (as nitrogen), respectively. The LODs were obtained at a signal to noise ratio (S/N) of 3. The values of the relative standard deviation (RSD) of peak area for these ions were 1.9 and 1.4%. The RSDs of peak height were 1.7 and 1.9%, the RSDs of migration time 0.11%. The proposed method was applied to the determination of nitrite and nitrate in a proposed certified reference material for nutrients in seawater, MOOS-1, distributed by the National Research Council of Canada (NRC). The results almost agreed with the assigned tolerance interval.
Mamoru Senna - One of the best experts on this subject based on the ideXlab platform.
-
an electron spin resonance study on the phase transition of the molecular assembly comprising Cetyltrimethylammonium Chloride cetyl alcohol water
Langmuir, 2000Co-Authors: And Yoshifumi Yamagata, Mamoru SennaAbstract:The phase transition process of a molecular assembly comprising Cetyltrimethylammonium Chloride (C16CA), cetyl alcohol (C16OH), and water was elucidated on the basis of electron spin resonance (ESR) spin probe method. ESR spectra for the ternary assembly incorporated with 5- and 16-doxylstearic acids (5-NS, 16-NS) showed definite anisotropic patterns, indicating restricted molecular motions in the bilayers. The order parameter, S33, and the hyperfine splitting constant AN‘ were higher in the 5-NS system than in the 16-NS. These findings suggest more marked restriction of molecular motions near the hydrophilic group in the bilayers and relatively free molecular motions toward the alkyl terminal. S33 and AN‘ for the 16-NS system were constant on aging, indicating invariance of the molecular motion and the degree of polarity near the terminal of alkyl group. A slight change of S33 for the 5-NS system was observed after aging for a few days. An empirical P parameter, a ratio of a fluid-like bilayer component ...
-
effects of temperature on the development of the internal structure of the Cetyltrimethylammonium Chloride cetyl alcohol water system
Langmuir, 1999Co-Authors: Yoshifumi Yamagata, Mamoru SennaAbstract:Cetyltrimethylammonium Chloride (C16CA) is added to a saturated solution containing an excess of aggregated spherical white solid globules of cetyl alcohol (C16OH) to give a semitranslucent gel (STG) spontaneously without stirring. Its internal structure was compared by morphology and thermal properties with a ternary mixture system (TMS) of the same composition but prepared by mixing and stirring at 75 °C. While dispersed particles in the TMS are multilamellar vesicles, the STG consists of anisotropic lamellae. The melting point is lower for lamellae than for vesicles because of the higher water content between lamellae. The interlamellar water content plays a critical role in the structural difference between the two assemblies.
-
change in viscoelastic behaviors due to phase transition of the assembly comprising Cetyltrimethylammonium Chloride cetyl alcohol water
Langmuir, 1999Co-Authors: Yoshifumi Yamagata, Mamoru SennaAbstract:The phase transition process of molecular assembly comprising Cetyltrimethylammonium Chloride (C16CA), cetyl alcohol (C16OH), and water was analyzed on the basis of dynamic viscoelasticity, mainly by using Cole−Cole plots. The assembly prepared at 75 °C showed onionlike multilamellar vesicles (0.2−5 μm in diameter) immediately after preparation but transformed on aging into a rosary network of vesicles and finally fused into lamellae via polyhedra. The dynamic modulus (G‘) of the assembly monotonically increased with frequency, while the loss modulus (G‘ ‘) showed 2 peaks. The change in the angle parameters (αL, αS) calculated from Cole−Cole plots indicate the long and short time relaxation mechanisms, corresponding to the network of coagulated vesicles and lamellae, respectively.
Jiu-ju Feng - One of the best experts on this subject based on the ideXlab platform.
-
flower like platinum cobalt ruthenium alloy nanoassemblies as robust and highly efficient electrocatalyst for hydrogen evolution reaction
Journal of Colloid and Interface Science, 2020Co-Authors: Hongyan Chen, Jiu-ju Feng, Huajie Niu, Xuexiang Weng, Hong Huang, Ai-jun WangAbstract:Abstract Exploring hydrogen evolution reaction (HER) catalyst with highly catalytic features in alkaline conditions is considered as significance for water splitting. In this study, a general and simple method was developed to prepare flower-like platinum-cobalt-ruthenium alloy nanoassemblies (PtCoRu NAs) by using murexide and Cetyltrimethylammonium Chloride (CTAC) as the co-structure-directing agents. Benefiting from the structural advantages and multimetallic compositions, the as-prepared PtCoRu NAs displayed remarkably enhanced electrocatalytic performance for the HER in 1.0 M KOH, with a low overpotential (η, 22 mV) to drive 10 mA cm−2, small Tafel slope (46 mV dec−1), and high exchange current density (j0, 3.30 mA cm−2) during the long-term electrolysis. The as-developed strategy sheds some valuable guidelines for preparing advanced multimetallic catalysts for production of hydrogen in fuel cells.
-
one pot solvothermal synthesis of three dimensional hollow ptcu alloyed dodecahedron nanoframes with excellent electrocatalytic performances for hydrogen evolution and oxygen reduction
Journal of Colloid and Interface Science, 2019Co-Authors: Hongyan Chen, Jiu-ju Feng, Qianli Zhang, Ai-jun WangAbstract:Abstract It is a great challenge to develop simple approach to construct three-dimensional (3D) bimetallic alloyed nanoframes (NFs) with tunable surface structures, albeit with the availability of noble metal NFs in catalysis. Herein, a one-pot solvothermal method was employed for scalable preparation of uniform hollow PtCu rhombic dodecahedron nanoframes (PtCu RDNFs) in the presence of Cetyltrimethylammonium Chloride (CTAC), where diglycolamine (DGA) served as the co-reductant and co-structure director. The above architectures had the larger electrochemically active surface area (ECSA, 36.85 m2 g−1Pt) than that of commercial Pt black (15.85 m2 g−1Pt), along with the improved catalytic characters for hydrogen evolution reaction (HER) and oxygen reduction reaction (ORR) in acid electrolytes alternative to those of Pt black. It demonstrates great potential applications of PtCu RDNFs in fuel cells and beyond.
-
a novel electrochemical immunosensor for highly sensitive detection of prostate specific antigen using 3d open structured ptcu nanoframes for signal amplification
Biosensors and Bioelectronics, 2019Co-Authors: Yao Chen, Ai-jun Wang, Lu Zhang, Peixin Yuan, Xiliang Luo, Yadong Xue, Jiu-ju FengAbstract:Abstract Herein, a novel electrochemical ultrasensitive immunosensor was designed for detecting prostate-specific antigen (PSA) with three-dimensional (3D) PtCu hollow nanoframes (PtCu HNFs) as signal amplification. The highly opened PtCu HNFs were synthesized by a one-pot solvothermal method with Cetyltrimethylammonium Chloride (CTAC) and trishydroxymethyl aminomethane (Tris) as co-structuring directors. The architectures enlarged the loading of prostate specific antibodies (Ab) and efficiently catalyzed hydrogen peroxide (H2O2) reaction, ultimately amplifying the signals. And polylysine was used to disperse PtCu HNFs, improve the biocompatibility and bind the Ab on the electrode surface. The fabricated immunosensor exhibited lower detection limit (0.003 ng mL–1, S/N = 3), and wider linear range (0.01–100.0 ng mL–1), along with the improved reproducibility, selectivity and stability for the assay of PSA. Thus, it is a desirable platform for PSA detection in clinical diagnosis and practical applications.
-
One-Step Synthesis of PtCu Alloyed Nanocages with Highly Open Structures as Bifunctional Electrocatalysts for Oxygen Reduction and Polyhydric Alcohol Oxidation
2018Co-Authors: Xian-yan Huang, Ai-jun Wang, Xiao-fang Zhang, Lu Zhang, Jiu-ju FengAbstract:Three-dimensional (3D) bimetallic PtCu alloyed nanocages (NCs) with highly open structures and large external- and internal-surfaces accessible for reactants were facilely synthesized by a one-pot solvothermal method. Arginine and Cetyltrimethylammonium Chloride (CTAC) acted as the costructure-directors and stabilizing agents. The resultant PtCu NCs showed significantly enhanced catalytic activity and improved stability when compared to commercial Pt/C (50 wt %) and Pt black catalysts toward oxygen reduction reaction (ORR), ethylene glycol oxidation reaction (EGOR), and glycerol oxidation reaction (GOR) in alkaline electrolyte. This work provides guidelines for rational synthesis of highly open cagelike architectures
-
Solvothermal Synthesis of Monodisperse PtCu Dodecahedral Nanoframes with Enhanced Catalytic Activity and Durability for Hydrogen Evolution Reaction
2018Co-Authors: Xiao-fang Zhang, Ai-jun Wang, Lu Zhang, Junhua Yuan, Jiu-ju FengAbstract:Nanoframes (NFs) with highly open structures have attracted substantial attention because of their large surface area, three-dimensional structure and good stability, which are of significance to enhance the catalytic characters. However, it is still challenging to develop facile and efficient method to construct Pt-based NFs with tailored structures. Herein, a simple solvothermal method was developed to prepare monodisperse PtCu dodecahedral nanoframes (PtCu DNFs), where Cetyltrimethylammonium Chloride (CTAC) served as the structure-director and dispersing agent, oleylamine as reductant, allantoin as the co-structure-director and coreductant. The PtCu DNFs displayed remarkably improved catalytic performances for hydrogen evolution reaction (HER) in both acid and alkaline electrolytes relative to homemade PtCu nanopolyhedrons (NPHs), commercial Pt/C (20 wt%) and Pt black catalysts. The work offers some instructive guidelines for synthesis of novel metallic NFs as efficient HER catalysts
Hongyan Chen - One of the best experts on this subject based on the ideXlab platform.
-
flower like platinum cobalt ruthenium alloy nanoassemblies as robust and highly efficient electrocatalyst for hydrogen evolution reaction
Journal of Colloid and Interface Science, 2020Co-Authors: Hongyan Chen, Jiu-ju Feng, Huajie Niu, Xuexiang Weng, Hong Huang, Ai-jun WangAbstract:Abstract Exploring hydrogen evolution reaction (HER) catalyst with highly catalytic features in alkaline conditions is considered as significance for water splitting. In this study, a general and simple method was developed to prepare flower-like platinum-cobalt-ruthenium alloy nanoassemblies (PtCoRu NAs) by using murexide and Cetyltrimethylammonium Chloride (CTAC) as the co-structure-directing agents. Benefiting from the structural advantages and multimetallic compositions, the as-prepared PtCoRu NAs displayed remarkably enhanced electrocatalytic performance for the HER in 1.0 M KOH, with a low overpotential (η, 22 mV) to drive 10 mA cm−2, small Tafel slope (46 mV dec−1), and high exchange current density (j0, 3.30 mA cm−2) during the long-term electrolysis. The as-developed strategy sheds some valuable guidelines for preparing advanced multimetallic catalysts for production of hydrogen in fuel cells.
-
one pot solvothermal synthesis of three dimensional hollow ptcu alloyed dodecahedron nanoframes with excellent electrocatalytic performances for hydrogen evolution and oxygen reduction
Journal of Colloid and Interface Science, 2019Co-Authors: Hongyan Chen, Jiu-ju Feng, Qianli Zhang, Ai-jun WangAbstract:Abstract It is a great challenge to develop simple approach to construct three-dimensional (3D) bimetallic alloyed nanoframes (NFs) with tunable surface structures, albeit with the availability of noble metal NFs in catalysis. Herein, a one-pot solvothermal method was employed for scalable preparation of uniform hollow PtCu rhombic dodecahedron nanoframes (PtCu RDNFs) in the presence of Cetyltrimethylammonium Chloride (CTAC), where diglycolamine (DGA) served as the co-reductant and co-structure director. The above architectures had the larger electrochemically active surface area (ECSA, 36.85 m2 g−1Pt) than that of commercial Pt black (15.85 m2 g−1Pt), along with the improved catalytic characters for hydrogen evolution reaction (HER) and oxygen reduction reaction (ORR) in acid electrolytes alternative to those of Pt black. It demonstrates great potential applications of PtCu RDNFs in fuel cells and beyond.