To obtain a deeper understand of the energy transfer mechanism between Ce and Tb ions in the aluminum garnet hosts, (Ce, Tb, Gd)GaAlO (GGAG:Ce, Tb) single crystals grown by the optical floating zone (OFZ) method were investigated systematically in a wide range of Tb doping concentration (1-66 at.%). Among those, crystal with 7 at.
View Article and Find Full Text PDFAs one of the most mature battery systems, the silver-zinc battery holds huge promise in the field of aqueous rechargeable batteries due to superior performance, high safety and environmental friendliness. It is urgent to improve the areal capacity of silver-zinc batteries so far. This study reports a novel Cu-supported Ag Nanowires (Cu@AgNAs abbreviation of Cu@AgNAs, Cu@AgNAs, Cu@AgNAs, Cu@AgNAs and Cu@AgNAs) as binder-free cathodes for high performance rechargeable aqueous silver-zinc batteries.
View Article and Find Full Text PDFThere is an urgent need to design practical aqueous rechargeable batteries (ARBs) with high energy density and long cycle life, using state-of-the-art cathode materials with low toxicity and environmental friendly nature. In virtue of the stable discharge potential and high energy density, silver (Ag) presents a huge perspective in the field of aqueous batteries. Herein, the paradigm of a novel core-shell Ag@Cu structure in situ Cu porous nanowire array skeleton (Ag@Cu NWA) is designed as the efficient cathode of an ARB.
View Article and Find Full Text PDFThe search for active catalysts that efficiently oxidize methane under ambient conditions remains a challenging task for both C1 utilization and atmospheric cleansing. Here, we show that when the particle size of zinc oxide is reduced down to the nanoscale, it exhibits high activity for methane oxidation under simulated sunlight illumination, and nano silver decoration further enhances the photo-activity via the surface plasmon resonance. The high quantum yield of 8% at wavelengths <400 nm and over 0.
View Article and Find Full Text PDFSensors (Basel)
February 2015
Response of highly sensitive SnO2 semiconductor carbon monoxide (CO) gas sensors based on target gas CO quasi-molecular-imprinting mechanism design is investigated with gas concentrations varied from 50 to 3000 ppm. SnO2 nanoparticles prepared via hydrothermal method and gas sensor film devices SC (exposed to the target gas CO for 12 h after the suspension coating of SnO2 film to be fully dried, design of quasi-molecular-imprinting mechanism, the experiment group) and SA (exposed to air after the suspension coating of SnO2 film to be fully dried, the comparison group) made from SnO2 nanoparticles are all characterized by XRD, SEM and BET surface area techniques, respectively. The gas response experimental results reveal that the sensor SC demonstrates quicker response and higher sensitivity than the sensor SA does.
View Article and Find Full Text PDFSensors (Basel)
December 2014
This work presents a new route to design a highly sensitive SnO2-based sensor for acetone gas enhanced by the molecular imprinting technique. Unassisted and acetone-assisted thermal synthesis methods are used to synthesis SnO2 nanomaterials. The prepared SnO2 nanomaterials have been characterized by X-ray powder diffraction, scanning electron microscopy and N2 adsorption-desorption.
View Article and Find Full Text PDFPhotocatalytic oxidation of ethylene continues to be a challenge at the frontier of chemistry. In a previous report, a simple Ag3 PO4 semiconductor material was shown to have strong photooxidative properties and efficiently oxidised water and decomposed organics in aqueous solution under visible-light illumination. Herein, its effects on the photo-oxidation of gaseous C2 H4 were investigated by fabricating graphitic C3 N4-Ag3 PO4 composite semiconductors with direct Z-scheme configuration.
View Article and Find Full Text PDFLi-ion batteries' (LIBs) performance proves to be highly correlated with ionic and electrical transport kinetics in electrodes. Although continual progress has been achieved in rational design of ideal electrode systems, their energy density, cyclic endurance and productivity are still far from perfect for practical use. Herein we propose an interesting, facile and versatile strategy to encapsulate various nanoscale metal oxides (covering both nanopowders and nanostructured arrays) into an ultrathin Ni matrix (metal oxide@Ni) for superior LIBs.
View Article and Find Full Text PDFThe electrochemical performance of supercapacitors relies not only on the exploitation of high-capacity active materials, but also on the rational design of superior electrode architectures. Herein, a novel supercapacitor electrode comprising 3D hierarchical mixed-oxide nanostructured arrays (NAs) of C/CoNi3 O4 is reported. The network-like C/CoNi3 O4 NAs exhibit a relatively high specific surface area; it is fabricated from ultra-robust Co-Ni hydroxide carbonate precursors through glucose-coating and calcination processes.
View Article and Find Full Text PDFControlled integration of multiple semiconducting oxides into each single unit of ordered nanotube arrays is highly desired in scientific research for the realization of more attractive applications. We herein report a diffusion-controlled solid-solid route to evolve simplex Co(CO3)0.5(OH)0.
View Article and Find Full Text PDFThe areal capacity of lithium-ion microbatteies (LIMBs) can be potentially increased by adopting a three-dimensional (3D) architectured electrode. Herein, we report the novel 3D Ni/SnOx/C hybrid nanostructured arrays that were built directly on current collectors via a facile hydrothermal method followed by a calcination-reduction process. Branched SnO2 nanorods grew uniformly on Ni2(OH)2CO3 nanowall arrays, resulting in the formation of precursors with a 3D interconnected architecture.
View Article and Find Full Text PDFMetal oxide nanostructures are promising electrode materials for lithium-ion batteries and supercapacitors because of their high specific capacity/capacitance, typically 2-3 times higher than that of the carbon/graphite-based materials. However, their cycling stability and rate performance still can not meet the requirements of practical applications. It is therefore urgent to improve their overall device performance, which depends on not only the development of advanced electrode materials but also in a large part "how to design superior electrode architectures".
View Article and Find Full Text PDFIn the title three-dimensional tetrazolate-based coordination polymer, poly[bis(μ(3)-cyanido-κ(3)N:C:C)[μ(5)-5-(pyridin-4-yl)tetrazolato-κ(5)N:N':N'':N''':N'''']tricopper(I)], [Cu(3)(C(6)H(4)N(5))(CN)(2)](n), there are two types of coordinated Cu(I) atoms. One type exhibits a tetrahedral environment and the other, residing on a twofold axis, adopts a trigonal coordination environment. The closest Cu···Cu distance is only 2.
View Article and Find Full Text PDFA novel evolution strategy has been put forward to build a 3D interconnected core-shell Ni/MnO(2) hybrid on a current collector, which demonstrated stable cyclic performance and good rate capabilities when applied as the anode for Li-ion batteries.
View Article and Find Full Text PDFWe report a novel hydrothermal method for the synthesis of a Cu@C nanotube array on a centimeter-scale substrate for the first time. In this hydrothermal reaction process, employing the carbon coated ZnO nanorod array as an inexpensive and partially sacrificial template, along with the ZnO dissolving in the alkaline atmosphere, the formed Cu particles deposit and grow on the carbon surface gradually. Importantly, the carbon shell of the template is not only essential to the preservation of the array configuration, but also makes a significant contribution to the final nanostructure.
View Article and Find Full Text PDFWe report here for the first time the synthesis of two novel hierarchical homogeneous nanoarchitectures of TiO2 nanorods branched TiO2 nanotube arrays (BTs) and P25-coated TiO2 nanotube arrays (PCTs) using two-step method including electrochemical anodization and hydrothermal modification process. Then the photocurrent densities versus applied potentials of BTs, PCTs, and pure TiO2 nanotube arrays (TNTAs) were investigated as well. Interestingly, at -0.
View Article and Find Full Text PDFACS Appl Mater Interfaces
January 2011
Large-scale uniform α-Co(OH)₂ nanowire arrays (NWAs) with an average length of ∼20 μm grown on pyrolytic graphite (PG) were successfully synthesized by a hydrothermal method at 120 °C. Ultrasonication test was carried out toward the as-made nanoarray products and the result demonstrated their robust adhesion to graphitic substrate. After 300 s of sonication testing, α-Co(OH)₂ NWAs could still possess both integrated one-dimensional (1D) nanoarray architecture and good electronic connections with current collector.
View Article and Find Full Text PDFLithium ion battery (LIB) is potentially one of the most attractive energy storage devices. To meet the demands of future high-power and high-energy density requirements in both thin-film microbatteries and conventional batteries, it is challenging to explore novel nanostructured anode materials instead of conventional graphite. Compared to traditional electrodes based on nanostructure powder paste, directly grown ordered nanostructure array electrodes not only simplify the electrode processing, but also offer remarkable advantages such as fast electron transport/collection and ion diffusion, sufficient electrochemical reaction of individual nanostructures, enhanced material-electrolyte contact area and facile accommodation of the strains caused by lithium intercalation and de-intercalation.
View Article and Find Full Text PDFIn this paper an urchinlike MnO(2) nanoparticle was synthesized by hydrothermal method and applied to the protein electrochemistry for the first time. By using a carbon ionic liquid electrode (CILE) as the basal electrode, hemoglobin (Hb) was immobilized on the surface of CILE with chitosan (CTS) and MnO(2) nanoparticle composite materials. Spectroscopic results indicated that Hb molecules retained its native structure in the composite film.
View Article and Find Full Text PDFZnO nanorod array grown directly on an inert alloy substrate has been modified with carbon by a simple immersion-calcination route and further used as the working electrode to construct a hydrazine sensor. The C@ZnO nanorod array-based sensor demonstrates a very high sensitivity of 9.4 muA muM(-1) cm(-2) and a low detection limit of 0.
View Article and Find Full Text PDFA new composite material consisted of hyaluronic acid (HA), ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIM]BF(4)) and cadmium sulfide (CdS) nanorod was fabricated and used for the immobilization of horseradish peroxidase (HRP) on the surface of a carbon ionic liquid electrode (CILE), which was prepared with 1-ethyl-3-methyl-imidazolium ethylsulphate ([EMIM]EtOSO(3)) as modifier. Spectroscopic results indicated that HRP remained its native structure in the composite film. Based on the synergistic effect of the materials used, an obvious promotion to the direct electron transfer efficient between HRP and CILE was achieved with a pair of well-defined redox peaks appeared in 0.
View Article and Find Full Text PDFNanoscale Res Lett
January 2010
Carbon-coated SnO(2) nanorod array directly grown on the substrate has been prepared by a two-step hydrothermal method for anode material of lithium-ion batteries (LIBs). The structural, morphological and electrochemical properties were investigated by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and electrochemical measurement. When used as anodes for LIBs with high current density, as-obtained array reveals excellent cycling stability and rate capability.
View Article and Find Full Text PDFNanoscale Res Lett
May 2010
SnO2 nanorod array grown directly on alloy substrate has been employed as the working electrode of H2O2 biosensor. Single-crystalline SnO2 nanorods provide not only low isoelectric point and enough void spaces for facile horseradish peroxidase (HRP) immobilization but also numerous conductive channels for electron transport to and from current collector; thus, leading to direct electrochemistry of HRP. The nanorod array-based biosensor demonstrates high H2O2 sensing performance in terms of excellent sensitivity (379 μA mM-1 cm-2), low detection limit (0.
View Article and Find Full Text PDFCarbon-modified Bi(2)WO(6) (C-Bi(2)WO(6)) nanostructures were synthesized via a hydrothermal process in the presence of glucose followed by the calcination in Ar gas at 500 degrees C. The morphologies and crystallinity of Bi(2)WO(6) and the nature of carbon in the composites obtained with different glucose amounts were characterized. Raman spectrum analysis, electron microscopy results and light absorption of C-Bi(2)WO(6) at wavelengths larger than 450 nm clearly confirmed the carbon modification.
View Article and Find Full Text PDFHigh surface area ZnO-carbon composite tubular arrays on a ceramic substrate were successfully synthesized by a hydrothermal process and a subsequent nanoscale diffusion-related reaction within the carbonaceous species-coated ZnO rod arrays during 900 degrees C annealing.
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