Liquid Phase Deposition Method Research Articles

Synthesis of two-dimensional nanowall of Cu-Doped TiO2 and its application as photoanode in DSSCs

Two-dimensional nanowall of Cu-doped TiO2 (CuTNW) has been prepared in this work to study the role of Cu doping on its photoactivity properties and its photovoltaic performance as photoanode in a dye-sensitized solar cell (DSSC). TiO2 nanowall with five Cu ion doping, i.e. 6.25, 12.5, 25.0, 50.0 and 100.0mM, were prepared via a liquid-phase deposition method using ammoniumhexafluorotitanate and hexamethylenetetramine as the reagents with a growth temperature of 90°C. The X-Ray Diffraction (XRD), X-ray energy dispersion (EDX) and diffuse optical reflectance spectroscopy analysis results confirmed the successfulness of the Cu doping process in the TiO2 nanowall and effective modification on the photoactivity of the TiO2 nanowall. We found that the power conversion efficiency of the DSSC utilizing TiO2 nanowall as photoanode can be enhanced up to 2 times, i.e. from 0.2% to 0.44%, when the TiO2 nanowall doped with Cu ion. The nanostructure preparation, device fabrication and the mechanism for the device performance enhancement will be discussed.

Activated porous carbon wrapped sulfur sub-microparticles as cathode materials for lithium sulfur batteries

The lithium-sulfur batteries holds a high theoretical capacity and specific energy, which is 4-5 times larger than that of today’s lithium-ion batteries, yet the low sulfur loading and large particles in the cathode greatly offset its advantage in high energy density. In the present paper, a liquid phase deposition method was introduced to synthesize sub-micro sulfur particles, which utilized as cathode materials after composed with activated porous carbon. Compared with common sublimed sulfur cathodes, as-obtained composite cathode shows an enhanced initial discharge capacity from 840.7 mAh/g to 1093 mAh/g at C/10. The reversible specific capacity after 50 cycles increased from 383 mAh/g to 504 mAh/g. The developed method has the advantages of simple process, convenient operation and low cost, and is suitable for the industrial preparation of lithium/sulfur batteries.

Comparative study of the properties of TiO2 nanoflower and TiO2-ZnO composite nanoflower and their application in dye-sensitized solar cells

We report the comparative study of TiO2 nanoflower (NF) and TiO2-ZnO composite NF in terms of properties and dye-sensitized solar cell performances. TiO2 NF has been constructed by using the simple liquid phase deposition (LPD) method while TiO2-ZnO composite NF was prepared by using dip-coating method in which the as-prepared TiO2 NF was immersed into ZnO growth solution. The power conversion efficiency of the DSSC utilizingTiO2-ZnO composite NF is higher (0.62 ± 0.02%) compared to TiO2 NF (0.17 ± 0.10%) due to higher photon absorption, dye loading, R cr, and longer electron life time than those of TiO2 NF.

Dependence of Interlayer Distance on the Charge Transfer Reaction of Ni-Al Layered Double Hydroxides

Ni-Al layered double hydroxide (LDH) is anode materials of the nickel metal hydride battery for high electrochemistry properties because of its structural stability of alkali electrolyte and smallness of volume change in the case of charge and discharge. LDH has interlayer anionic exchange property and changes at the interlayer distance by anionic exchange. In this study, Ni-Al LDH was synthesized by Liquid phase deposition (LPD) method and its interlayer distance was extended by anionic exchange. Then electrodes were made by the anion-exchanged LDH and checked relations between interlayer distance and internal resistance. Interlayer distances of Ni-Al LDH which calculated from d 003 values increase with the diameters of intercalated anions. The interlayer distance of LDH depends on the molecular shape and size of intercalated anions. The decrease of charge transfer resistance is obviously observed at about 300-400 pm of LDH interlayer distance, and the activation energy for charge transfer also decrease with the increasing of LDH interlayer distance.

1D core–shell magnetoelectric nanocomposites by template-assisted liquid phase deposition

We demonstrate here that the liquid phase deposition (LPD) method, a simple, low cost and highly reproducible synthetic approach generally used for the deposition of high quality metal oxide thin films, can be reliably extended to the rational design of 1D magnetoelectric core–shell nano-architectures. In the first step of the process, highly crystalline ferroelectric (BaTiO3) nanotubes with an average diameter of 200 nm and controllable wall thickness were synthesized by the controlled hydrolysis of metal oxyfluoride precursors upon immersing alumina templates into a treatment solution at temperatures as low as 40 °C. The resulting perovskite nanotubes immobilized within the channels of the anodic aluminum oxide (AAO) membranes have been subsequently filled with a spinel ferrite phase, with the chemical composition Zn1.5Fe1.5O4 yielding spinel-perovskite 1D core–shell magnetoelectric architectures. The resulting core–shell tubular nanocomposites have been characterized structurally, morphologically and compositionally and their ferroelectric, magnetic and magnetoelectric properties have been measured. A change from a superparamagnetic to a ferrimagnetic behavior was observed when the pristine spinel ferrite nanotubes were incorporated into the spinel-perovskite core–shell nanocomposites, indicating the existence of a magnetoelectric coupling between the two ferroic phases. Moreover, the measured magnetoelectric coupling coefficient was α = 1.08 V cm−1 Oe−1, a value which is superior to the values reported for similar thin film and tubular spinel ferrite magnetoelectric nanocomposites, thereby indicating a strong strain-mediated coupling between the ferroelectric and magnetostrictive phase in the 1D core–shell nanocomposites and making these materials suitable for implementation into various functional devices.

Anticorrosion and Scale Behaviors of Nanostructured ZrO2–TiO2Coatings in Simulated Geothermal Water

Corrosion and scaling phenomena often appear simultaneously and act synergistically in geothermal water system. We prepared the nano-ZrO2–TiO2 composite coatings on the AISI type 304 stainless steel with the chemical liquid phase deposition method. Surface morphology, crystal form, and chemical elements of the coatings were investigated with field emission scanning electron microscopy, energy-dispersive X-ray spectroscopy analyzer, X-ray diffraction, and thermal gravimetric/differential thermal analyses instruments, respectively. Corrosion behaviors and scale properties were tested by potentiodynamic polarization and electrochemical impedance spectroscopy measurements in the simulated geothermal water at 50 °C. The results reveal that the anticorrosion performance of the ZrO2–TiO2 composite coating is markedly improved compared to the austenitic stainless steels. A pitting corrosion and scale deposition mechanism was proposed for the ZrO2–TiO2 composite coating in the simulated geothermal water. These fin...

Facile synthesis of Ag/Ag3PO4/AMB composite with improved photocatalytic performance

Ag3PO4 exhibits extremely high photo-oxidative capabilities for organic pollutants decomposition under solar light. However, the relatively large crystallite size of Ag3PO4 lowers its light response, while the high conduction band potential intensifies the reduction to Ag0 by the light induced electron, limiting the practical application of Ag3PO4. To overcome these drawbacks, we herein adopted a facile liquid phase deposition method to load Ag3PO4 onto amino-modified biochar which is an abundant and cheap by-product of biomass pyrolysis to prepare renewable energy. The as-prepared composite (Ag/Ag3PO4/AMB) exhibited greatly enhanced photocatalytic performance to amoxicillin degradation compared with pure Ag3PO4. The results show that almost 80% amoxicillin was decomposed in 120min in the presence of Ag/Ag3PO4/AMB, whereas only 65% of the amoxicillin was degraded with pure Ag3PO4. Multiple characterizations including X-ray diffraction (XRD), scanning electron microscope (SEM), FTIR, Raman, and XPS revealed that Ag3PO4 particles were evenly distributed on the surface of biochar, and a few Ag NPs were also generated due to the reduction effect of AMB. UV–vis diffuse reflectance spectra (DRS) analysis revealed that the composite had good visible light response, while electrochemical impedance spectroscopy (EIS) measurements indicated AMB improved the efficiency of charge separation and electron transfer. In addition, EPR determination suggested that the oxidant formed in photocatalysis systems under visible light irradiation plays an important role in the degradation of amoxicillin.

EFEK KONSENTRASI Cu PADA STRUKTUR DAN SIFAT HANTARAN LISTRIK NANOPARTIKEL CuPt

The investigation of bimetallic CuPt Nanoparticles (CuPt NPs) with average diameters in the 196.7±98 nm range have been prepared by the Liquid phase deposition methods and synthesized directly on an indium tin oxide (ITO) substrate. CuPt NPs with high surface defect grown on (ITO) surface were prepared via a simple immersion of the substrate into a solution contains 1 mM Potassium Hexachloro Platinate (K 2 PtCl 6 ), 0.2 mM Anhydrous Copper (II) Sulfate (CuSO 4 ) anhydrous, 0.01 M Sodium dodecyl sulfate (SDS) and 10 mM Formic acid for 4 h at room temperature. The modification of Cu 2+ ion precursor play a role to determine the nanoparticles geometry obtained. The simultaneous reduction of metal ions leads to either a surface enriched with one component or an alloy type of structure depending on the bimetal composition. The bimetallic CuPt NPs dispersions are characterized by FESEM, EDX Mapping, XRD, HRTEM and XPS analysis. Key words: CuPt, Liquid phase deposition, Bimetallic CuPt NPs

Photoelectrochemical performances of the SnO2-TiO2 bilayer composite films prepared by a facile liquid phase deposition method

A facile liquid phase deposition (LPD) method was developed to prepare the SnO2-TiO2 bilayer composite films in this paper. The phase structure, surface morphology, and chemical composition of the as-prepared films were analyzed by X-ray diffraction (XRD), Scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS), respectively. It was observed that, the underlying TiO2 film consisted of nanorods and showed an acicular surface morphology, whereas the outer SnO2 layer consisted of tiny SnO2 nanosheets and exhibited a network-like surface morphology. The XPS results confirmed that the as-prepared LPD-derived SnO2-TiO2 composite films were co-doped with nitrogen and fluorine. Moreover, the photoelectrochemical measurements indicated that a typical n-type photoeffect were observed for the as-prepared LPD-derived films when illuminated by light. It was also found that, the photoelectrochemical performances of the SnO2-TiO2 bilayer composite films prepared with 0.1 M and 0.002 M (NH4)2TiF6 solutions could be relatively enhanced than that of the TiO2 monolayer films.

Synthesis and Characterization of Fibrous Bimetallic CuPt Nanoparticles

<p>This paper reports a facile methode for the synthesis of fibrous bimetallic CuPt Nanoparticles (CuPt NPs) using the liquid phase deposition methods deposited directly on an indium-tin oxide (ITO) substrate. The electron microscopy analysis result shows that CuPt NPs, constructed by networked-nanorod of diameter ca. 3.5 nm and length approximately 5.5 to 6.5 nm, exhibits a quasi spherical morphology and fibrous structure with diameter approximately 196±98 nm. The differences of individual element miscibility and the effect of lattice-mismatch between Pt and Cu is the key factor for the formation of fibrous structure. XPS analysis indicated that the fibrous bimetallic CuPt NPs feature metallic properties with highly reactive surface. This may increase the charge-transfer reactions in catalytic, electrochemistry and sensors application.</p><p> </p>

Synthesis and Characterization of Fibrous Bimetallic CuPt Nanoparticles

<p>This paper reports a facile methode for the synthesis of fibrous bimetallic CuPt Nanoparticles (CuPt NPs) using the liquid phase deposition methods deposited directly on an indium-tin oxide (ITO) substrate. The electron microscopy analysis result shows that CuPt NPs, constructed by networked-nanorod of diameter ca. 3.5 nm and length approximately 5.5 to 6.5 nm, exhibits a quasi spherical morphology and fibrous structure with diameter approximately 196±98 nm. The differences of individual element miscibility and the effect of lattice-mismatch between Pt and Cu is the key factor for the formation of fibrous structure. XPS analysis indicated that the fibrous bimetallic CuPt NPs feature metallic properties with highly reactive surface. This may increase the charge-transfer reactions in catalytic, electrochemistry and sensors application.</p><p> </p>

Dependence of Interlayer Distance on the Charge Transfer Reaction of Ni-Al Layered Double Hydroxides

Ni(OH)2 has been used as electrode material of nickel-metal hydride (Ni-MH) battery and hybrid capacitors. The application of Ni-Al LDH to the cathode material of Ni-MH were attracted owing to its structural stability and high electrochemical properties. The nickel positive active material for the alkali storage battery used widely at present is b-Ni(OH)2. Whereas, if Ni-Al LDH which is a higher-order oxide functions as an active material for a positive electrode, the oxidation reaction in the charging process becomes the multi-electron reaction because Ni-Al LDH has a type crystal structure. Therefore, the capacity per unit weight of the active material will increase, and a drastic improvement of the battery capacity will be achieved. Recently, the reaction products deposit by the interfacial reaction which the thin film continuously forms only on the surface of a solid phase by liquid phase deposition (LPD) method. The active material layers which are extremely adhered to the substrates can be constructed by the LPD method, accordingly, the charge transfer resistance between a current collector and an active material drastically decreased when a current collector is used as a substrate[1,2]. In this research, the Ni-Al LDH was synthesized by the LPD method, and the interlayer distance of the LDH has been changed by the intercalation of the anions which have various ionic radii into the interlayer of the LDH. Furthermore, the influence of the electrode on internal resistance by the interlayer distance of the Ni-Al LDH was discussed by using the layered double hydroxide sample as an active material. About 15% NH3 aq. was added into 0.4 mol L-1 Ni(NO3)2 aq. until pH 7.5 under stirring, and precipitated b-Ni(OH)2 was filtered off by suction filtration. 0.5 mol L–1 HF was added until the b-Ni(OH)2 dissolved as a nickel fluoride complex. The total F- ion concentration and pH of appropriate amount of the solution were adjusted by hydrofluoric acid and NH3 aq. to 200 mmol L-1 and 8.2, respectively. Then, the total Al3+ concentration was adjusted to 1.2 mmol L-1 by Al(NO3)3 aq. Carbon black powder (CB) or nickel foams (Ni foam) which apply the surface hydrophilization are added as a substrates into the solution, and reacted at 50 °C for 48 h. The prepared Ni-Al LDH(as-dep.LDH) as added the solutions of the various anions, and the anion exchange reaction in the interlayer of the LDH samples for 24 h were carried out. The electrode which made from the anion exchanged Ni-Al LDH as an active material was prepared as our previous report[2]. The Hg/HgO into 6 mol L-1 KOH aq. and the foam nickel plate were employed as the reference electrode and the counter electrode, respectively, while 6 mol L-1 KOH aq. served as an electrolyte solution. The electrochemical impedance spectroscopy (EIS) measurement was performed at 500 mV. The frequency range was 10 kHz - 50 mHz and the voltage amplitude was 5 mV. It was confirmed from the XRD measurement of the anion exchanged LDH that the interlayer distance (d003) of the Ni-Al LDH increased as the anionic radii increased. Neither complex ions (i.e., [Fe(CN)6]4-) nor surface active agent anions (i.e., dodecanesulfonic anion and dodecyl benzenesulfonic anion) did intercalate immediately into the interlayer of the as-dep.LDH because of their large ionic size. It was confirmed that the intercalation of the complex ions and surface active agent anions became possible after the increasing of the interlayer distance by the intercalation of SO4 2- as preliminary intercalation. Fig.1 shows the dependence of the interlayer distance of the Ni-Al LDH on the Ni foam as an active material on the charge transfer resistance (R ct) concerning the anion exchanged electrodes. It was obvious that the R ct values decrease as the interlayer distance increases. This is because the ion diffusion in the inter layer becomes easy because of the increase of the interlayer distance, and it can be considered that it is because the Rct value decreases by the improvement of the electrode reaction. Whereas, the interlayer distance dependence of the Ni-Al LDH on the CB substrate hardly appeared on the Rct value concerning the anion exchanged electrodes. It can be concluded that this is because the gross weight of the Ni-Al LDH on CB substrate is less than that on Ni foam, namely, in that case of the CB substrate, the influence on Rct by the increase of the interlayer distance of the active material is relatively slight. [1] H. Maki, et al., ACS. Appl. Mater. Interfaces, 7, 2015, 17188-17198. [2] M. Takigawa, et al., Electrochemistry, 83, 2015, 803-806. Figure 1

High-Performance Hybrid Supercapacitor with 3D Hierarchical Porous Flower-like Layered Double Hydroxide Grown on Nickel Foam As Binder-Free Electrode

The synthesis of layered double hydroxide (LDH) as electroactive material has been well reported; however, fabricating an LDH electrode with excellent electrochemical performance at high current density remains a challenge. In this paper, we report a 3D hierarchical porous flower-like NiAl-LDH grown on nickel foam (NF) through a liquid-phase deposition method as a high-performance binder-free electrode for energy storage. With large ion-accessible surface area as well as efficient electron and ion transport pathways, the prepared LDH-NF electrode achieves high specific capacity (1250 C g-1 at 2 A g-1 and 401 C g-1 at 50 A g-1) after 5000 cycles of activation at 20 A g-1 and high cycling stability (76.7% retention after another 5000 cycles at 50 A g-1), which is higher than those of most previously reported NiAl-LDH-based materials. Moreover, a hybrid supercapacitor with LDH-NF as the positive electrode and porous graphene nanosheet coated on NF (GNS-NF) as the negative electrode, delivers high energy density (30.2 Wh kg-1 at a power density of 800 W kg-1) and long cycle life, which outperforms the other devices reported in the literature. This study shows that the prepared LDH-NF electrode offers great potential in energy storage device applications. Figure 1

A facile route to synthesis of double-sided TiO2 nanotube arrays for photocatalytic activity

TiO2-based structure is fabricated on both sides of transparent quartz substrate via a liquid phase deposition method, with the assistance of ZnO nanorod template. The morphology, crystal structure, and photocatalytic property of the double-sided TiO2 nanotube arrays have been studied and the formation mechanism has been discussed. Importantly, compared to single-sided structure, the double-sided TiO2 nanotube arrays show remarkable enhancement of photocatalytic activity in degradation of Rhodamine B.

SnO2/polypyrrole hollow spheres with improved cycle stability as lithium-ion battery anodes

SnO2/polypyrrole (SnO2/PPy) hollow spheres were fabricated by a liquid-phase deposition method using colloidal carbon spheres as templates followed by an in-situ chemical-polymerization route. The obtained SnO2/PPy composite particles had a size of 610–730 nm. The thickness of inner shell (SnO2) and outer shell (PPy) for composites was about 35 and 90 nm, respectively. As an anode for lithium ion batteries, the SnO2/PPy composites electrode showed superior rate capability and excellent long-term cycling performance. After a long-term cycling of 600 cycles at different current densities, a capacity of 899 mAh g−1 was achieved at the current density of 100 mA g−1 for SnO2/PPy composites. The excellent electrochemical performance was attributed to the synergistic effect between the PPy coating layer and the hollow SnO2 spheres, which guaranteed vast lithium storage sites, good electronic conductivity, fast lithium ion diffusion, and sufficient void space to buffer the volume expansion.

Efficient mineralization of bisphenol A by photocatalytic ozonation with TiO2–graphene hybrid

In this paper, the catalytic ability of TiO2–reduced graphene oxide hybrid (TiO2–RGO) in photocatalysis and ozonation combined system was investigated. TiO2–RGO hybrid was prepared by liquid-phase deposition (LPD) method. TEM, XRD, FT-IR, UV–vis spectra were used to characterize the structure and optical property. Photoluminescence (PL) spectra demonstrate that the recombination of photogenerated charges is greatly inhibited by introduction of RGO. Bisphenol A (BPA) was used as model substances to evaluate the catalytic ability of TiO2–RGO. The effect of RGO content and stability of TiO2–RGO in photocatalytic ozonation was also studied. The results showed that photocatalytic ozonation of BPA with TiO2–RGO hybrid was a very effective method for BPA mineralization. The TOC removal efficiency reached 98.4% by TiO2–RGO/O3/UV in 45min, which is 1.17 times as great as that of TiO2/O3/UV process. Moreover, the catalytic ability of TiO2–RGO hybrid was very stable after recycling for five consecutive runs. This improvement is attributed to the improved separation efficiency of photo-generated charges, which facilitated the electrons trapping by ozone and enhanced the yield of hydroxyl radical.

Structural and optical characteristic of single crystal rutile-titania nanowire arrays prepared in alumina membranes

In this paper, the structural and optical characteristics of single crystal rutile-titania nanowires and the possible mechanism of photoluminescence are discussed. A template-assisted liquid phase deposition (LPD) method was employed to prepare the nanowire arrays. This approach produced a large quantity of nanowires at relatively high purity and good controllability. The samples were characterized by field emission scanning electron microscope (FESEM), transmission electron microscopy (TEM), energy-dispersive X-ray (EDX) spectroscopy, selected area electron diffraction (SAED), X-ray diffraction (XRD), Raman spectroscopy, UV–vis and photoluminescence spectroscopy. The results revealed that the obtained nanowire arrays were single crystal rutile-titania with the uniform diameter of 50–80 nm over their entire length. The UV–vis absorption spectroscopy displayed that rutile-titania nanowires possessed indirect optical allowed transition with the band gap of 3.06 eV. From the photoluminescence spectrum, it was found that rutile-titania had three strong luminescence bands at 410 (3.02 eV), 418 (2.97 eV), 422 nm (2.64 eV), which could be ascribed to the self-trapped excitons, defects and oxygen vacancies. The broad emission band centered at about 472 nm (2.63 eV) was associated to the charge transfer from Ti3+ to oxygen anion in a TiO68− complex associated with oxygen vacancies at the surface of nanowires. We believe that this photoluminescence behavior of the prepared titania nanowire arrays could be attributed to bound excitons emission, resulting in the trapping of free excitons by TiO6 octahedra near defects such as oxygen vacancies.

Development of optical biosensor based on photonic crystal made of TiO2 using liquid phase deposition

We fabricated a titanium dioxide (TiO2)-based photonic crystal (PhC) using liquid phase deposition (LPD) to develop highly sensitive optical biosensors. The optical characteristics of the PhCs in the visible region were sensitive to the change in the refractive index of the surrounding medium due to an antigen–antibody reaction; thus, applications using the optical biosensor are expected to be highly sensitive. However, a base material with a high refractive index is indispensable for the fabrication of the PhC. Here, TiO2, which has optical transparency in the visible region, was selected as the high refractive index base material. The present LPD method allowed fabrication using low-cost apparatus. Furthermore, the mild conditions of the LPD method led to formation of TiO2-based PhC with fewer crack structures. Finally, the anti-neuron-specific enolase antibody was immobilized onto the TiO2-based PhC surface, and 1–1000 ng/mL of the neuron-specific enolase antigen was successfully detected.

Liquid Phase Deposited TiO<sub>2</sub> Films on Stainless Steel Mesh for Corrosion Resistance Application

Liquid phase deposition (LPD) method was used to prepare corrosion protective titanium dioxide (TiO2) film coatings on the stainless steel mesh which is composed of steel wires at a relatively low temperature (80°C). The as-prepared TiO2 coated samples were characterized using X-ray diffractometry (XRD), scanning electron microscopy (SEM) and energy-dispersive X-ray spectra (EDX). It was observed that the TiO2 film coatings could conformally coat the stainless steel wires which play a significant role in the corrosion resistance. The corrosion resistance of the samples was evaluated using Tafel polarization curves in a three-electrode electrochemical examination system. The TiO2 deposited samples all showed a certain improvement of corrosion resistance. Compared with the sample prepared in the acid condition (PH=3.7), the low alkaline (PH=9.5) sample could provide better corrosion protection which could increase the corrosion potential (Ecorr) from-0.53 V to-0.17 V.

MOFs nanosheets derived porous metal oxide-coated three-dimensional substrates for lithium-ion battery applications

Porous nanosheet-structured materials have received great attention because of their promising applications in energy field. Construction of porous metal oxides nanosheets on three-dimensional (3D) electro-conductive substrates is an effective way to further enhance electrochemical performance of energy storage devices. Herein, porous transition metal oxides (i.e. ZnO, Co3O4) nanosheets derived from MOFs coated 3D substrates (i.e. 3D nickel foam, carbon fiber) are successfully synthesized by a facile liquid-phase deposition method with subsequent calcination. The growth mechanism of MOFs with nanosheet morphology coated 3D substrates is investigated. As a proof of concept application, the Co3O4/3DNF hybrid, possessing the advantages of porous nanosheet-structured and 3D electro-conductive substrates, is used as a binder-free anode material for lithium-ion battery, which exhibits high-rate capability and long-term cyclic stability. High discharge capacities of 1135, 1268, 1226, 1130, 923, 751, and 543mAhg−1 are obtained at the current densities of 0.2, 0.5, 1, 2, 5, 10, and 20Ag−1, respectively. Even measured at 25Ag−1, it still retains a desired discharge capacity of 364mAhg−1. Besides, the long-term cyclic stability up to 2000 cycles can be obtained at 5Ag−1 and 20Ag−1.