Facile Wet Chemical Method Research Articles

High-efficiently visible light-responsive photocatalysts: Ag3PO4 tetrahedral microcrystals with exposed {111} facets of high surface energy

In this article, single-crystalline tetrahedral Ag3PO4 microcrystals with exposed {111} facets was successfully synthesized via a facile wet chemical method. The tetrahedral Ag3PO4 with exposed {111} facets showed the highest photocatalytic activity in visible light irradiation among the {111}, {110} and {100} facets. By DFT calculations, it is demonstrated that the surface energy of the {111} facets is higher than that of the {110} and {100} facets. It was found that the largest band gap of the Ag3PO4 {111} surface is likely to suppress the recombination of electron–hole pairs by exploring the electronic structures of the different surfaces of Ag3PO4. Meanwhile, the dispersion between the valence bands and conduction bands of the {111} surface is beneficial for the separation of photogenerated electrons and holes on the {111} surface, which further improves the photocatalytic activity of the {111} surface.

Ultra-low loading Pt decorated coral-like Pd nanochain networks with enhanced activity and stability towards formic acid electrooxidation

Novel Pd based coral-like nanochain networks decorated with ultra-low loading (0.66 at%) Pt (Pt-on-PdCNNs) were successfully synthesized through a facile wet chemical method. The Pt-on-PdCNNs exhibited significantly enhanced activity and stability towards formic acid electrooxidation, which was ascribed to their unique properties such as the highly interconnected networks, the more exposed Pd(111) planes and the reduced CO formation and adsorption on the Pt–Pd surface.

Rhodium nanoparticle–carbon nanosphere hybrid material as an electrochemical hydrogen sensor

The highly monodispersed decoration of Rh nanoparticles (∼2.5 nm) on acid-functionalized carbon nanospheres (CNSs) has been demonstrated using a facile wet-chemical method. The electrochemical studies of the resulting Rh–CNS hybrid material displayed excellent H2 sensing properties.

Bienzyme-Functionalized Monodispersed Biocompatible Cuprous Oxide/Chitosan Nanocomposite Platform for Biomedical Application

The ultrafine monodispersed cuprous oxide (Ufm-Cu(2)O) nanoparticles have been successfully synthesized by a facile wet chemical method using poly-N-vinylpyrrolidone (PVP) as a capping agent. This colloidal solution of Ufm-Cu(2)O and chitosan (CS) is electrophoretically deposited (EPD) onto the indium tin-oxide (ITO) glass substrate. Thus synthesized nanocomposite has been characterized by X-ray powder diffraction (XRD, ∼6 nm), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and Fourier transform infrared (FTIR) spectroscopic techniques. This novel biomedical nanocomposite platform has been explored to fabricate a cholesterol biosensor by immobilizing cholesterol esterase (ChEt) and cholesterol oxidase (ChOx) onto Ufm-Cu(2)O-CS/ITO electrode surface. The seed germination tests of these biomaterials (Ufm-Cu(2)O-CS nanocomposite and ChOx-ChEtUfm-CuO(2)-CS nanobiocomposite), conducted using the disc diffusion method, reveal strong activity against the common pathogens and crops, indicating biocompatibility of the nanocomposite. Under optimized conditions, the linearity between the current response and the cholesterol concentration has been obtained in the range of 10-450 mg/dL, with detection limit of 15.9 mg/dL cm(-2) and a high sensitivity of 0.895 μA/(mg/dL cm(-2)). The proposed biocompatible ChEt-ChOx/Ufm-Cu(2)O-CS/ITO bioelectrode shows fast response time (<5 s), good reproducibility, and long-term stability. This biocompatible biosensor has been used to determine the total cholesterol levels in human serum samples. Investigated antimicrobial activities of bienzyme-functionalized Ufm-Cu(2)O-CS nanocomposite are the potential platform for biomedical applications.

The novel, one step and facile synthesis of ZnO nanoparticles using heteropolyoxometalates and their photoluminescence behavior

A novel and facile wet chemical method is presented to synthesize zinc oxide nanoparticles (NPs) under ambient atmosphere and temperature. Keggin type heteropolyoxometalate (H3[PW12O40]) was used as stabilizer and the effect of stirring time and amount of H3[PW12O40] (HPW) were studied. XRD and TEM techniques were applied for the morphological and structural characterizations of NPs. Size of nanoparticles were determined using TEM, Scherrer’s formula as well as effective mass approximation. The results of these three methods are in good agreements and revealed single hexagonal zincite type crystalline with average particle size in the range of 3–15nm. Photoluminescence behavior of the prepared sample shows a strong orange to red emission centred at about 620–635nm, a green emission at around 550nm and broad UV emission at around 400nm.

Highly Dispersive Deposition of Pt Nanoparticles on CdS Nanostructures for Photocatalytic Hydrogen Evolution

Abstract We have succeeded in depositing monodisperse 1 nm Pt nanoparticles (NPs) on cadmium sulfide (CdS) nanostructures by employing a facile wet-chemical method. This approach is applicable for various CdS nanostructures regardless of their size, shape, and crystal structure. Moreover, photocatalytic measurements revealed that the Pt NP-deposited CdS NPs showed higher activity than those synthesized by photodeposition did. The mechanism of Pt NP deposition on CdS was investigated using transmission electron microscopy, X-ray diffraction analysis, X-ray fluorescence analysis, and absorption spectroscopy.

In situ fabrication of Bi2S3 nanocrystal film for photovoltaic devices

A facile wet-chemical method to prepare Bi2S3 thin films with flake nanostructures directly on ITO glass substrate is presented in this paper for the first time. The product was characterized by X-ray powder diffractometer (XRD), Raman spectrometer, scanning electron microscope (SEM), and atomic force microscope (AFM). The one-step solvothermal elements treatment on the ITO substrate spare time to form film by spin-coating process and the film could be tightly attached to the ITO electrode. A conjugated polymer, poly 3-hexylthiophene (P3HT), was then spin-coated on the as-prepared Bi2S3 film to form an inorganic-organic hybrid thin film. The photovoltaic performance of the resulting solar cell device was also investigated.

A facile synthesis of Ag Modified ZnO nanocrystals with enhanced photocatalytic activity

Ag modified ZnO (Ag/ZnO) nanocrystals were prepared by a facile and low temperature wet chemical method. The phase structures, morphologies, and optical properties of the as-prepared samples were characterized by X-ray powder diffraction (XRD), field-emission scanning electron microscopy (FESEM), high-resolution transmission electron microscopy (HRTEM), the Brumauer-Emmett-Teller (BET) surface area, UV-vis diffuse reflectance spectroscopy and photoluminescence (PL) spectra, respectively. The photocatalytic performance of Ag/ZnO with diffent Ag contents was measured with the degradation of methyl orange (MO) at room temperature under UV light irradiation. The experimental results indicated that the well-crystalline ZnO nanopaticles with a size of ca. 4.5 nm exhibited a high photocatalytic activity for the degradation of MO with the apparent rate constant (k) of 1.57 ×10−2 min−1, and the photocatalytic activities of ZnO were further enhanced by modification with silver. When the Ag loading was 3mol%, Ag/ZnO showed the highest photocatalytic acitivity with a k value of 5.452×10−2 min−1, which is 3.5 and 2.5 time more than that of ZnO and commercial P25, respectively.

Upright-standing SnO2 nanowalls: Fabrication, dual-photosensitization and photovoltaic properties

We report on fabrication of upright-standing SnO2 nanowalls aligned on FTO substrates by a facile wet chemical method at low temperature. These nanowalls are dual-photosensitized with CdS quantum dots and Z907 dye molecules in order to construct panchromatic dye-sensitized solar cells. We demonstrate that thin CdS quantum dot layer not only acts as a blocking layer preventing recombination of charge carriers, but also contributes as a light absorber. A 158% improvement in power conversion efficiency is observed, which is attributed to improved light absorption, reduced recombination and improved charge collection in presence of CdS quantum dot interlayer.

The controllable synthesis of chain-like TiO2 networks with multiwalled carbon nanotubes as templates and its application for dye-sensitized solar cells

The anatase TiO2 nanostructure with large surface area and fast photoelectron-transfer channel can be an ideal structure for the fabrication of dye-sensitized solar cell (DSSC) photoelectrode. The high surface area can provide more sites for dye adsorption, while fast photoelectron-transfer channel can enhance the photogenerated electron transfer to complete the circuit. In this work, the chain-like TiO2 networks with large surface area and long particulate connection structure have been obtained through a facile wet-chemical method using multiwalled carbon nanotubes as templates. The diameter of TiO2 chain is ca. 15 nm and its interconnection degree can be controlled by adjusting the amount of reactive reagent. DSSC based with dense interconnection chain-like TiO2 network photoelectrode exhibits higher conversion efficiency (6.58 %), which is higher than that of DSSC based on photoelectrode with sparse interconnection chain-like TiO2 or conventional P25 nanoparticles under the same conditions. This is because it has higher surface area and the fastest interfacial charge transfer, which is proved by N2 sorption isotherms and electrochemical impedance spectra.

Fabrication, Characterization and Photocatalytic Capability of ZnAl&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;4&lt;/sub&gt; Nanospheres

Developing photocatalysts with specific morphology promises good opportunities to discover the geometry dependent properties. Porous and spherical shaped superstructure of ZnAl2O4was successfully synthesized by a facile wet chemical solution-phase method. Their surface morphology and structure were investigated by X-ray powder diffraction, scanning electron microscopy, energy dispersive spectra and Brunauer-Emmet-Teller N2gas adsorption-desorption isotherms. The optical property of the ZnAl2O4nanospheres were studied by UV-vis diffuse reflectance spectroscopy. The ZnAl2O4nanospheres exhibited a good photocatalytic activity in degrading rhodamine B.

A novel and facile wet-chemical method for synthesis of silver microwires

A novel and facile wet-chemical method for synthesis of silver microwires was developed. The well-defined particles were prepared by adding an iron (II) sulfate heptahydrate solution into a silver nitrate solution containing citric acid drop by drop at 50 °C. The resulting products were characterized by scanning electron microscopy and X-ray diffraction. It was found that the particles consisted of numerous silver microwires. The reaction temperature greatly affected the morphologies of the as-prepared particles. Both of the mean length and width of the silver microwires increased with the decrease of the concentration of silver nitrate. And the lower concentration was unfavorable for the formation of more silver microwires. Similar findings were also observed when the concentration of iron (II) sulfate was decreased. The amount of citric acid also greatly affected the shape of the as-prepared particles. It was concluded that citric acid was the key role in the formation of silver microwires via the Oswald ripening mechanism.

A general method for the large-scale synthesis of uniform ultrathin metal sulphide nanocrystals

Ultrathin metal sulphide nanomaterials exhibit many unique properties, and are thus attractive materials for numerous applications. However, the high-yield, large-scale synthesis of well-defined ultrathin metal sulphide nanostructures by a general and facile wet-chemical method is yet to be realized. Here we report a universal soft colloidal templating strategy for the synthesis of high-quality ultrathin metal sulphide nanocrystals, that is 3.2 nm-thick hexagonal CuS nanosheets, 1.8 nm-diameter hexagonal ZnS nanowires, 1.2 nm-diameter orthorhombic Bi(2)S(3) nanowires and 1.8 nm-diameter orthorhombic Sb(2)S(3) nanowires. As a proof of concept, the ultrathin CuS nanosheets are used to fabricate an electrode for a lithium-ion battery, which exhibits a large capacity and good cycling stability, even after 360 cycles. Furthermore, high-yield, gram-scale production of these ultrathin metal sulphide nanomaterials has been achieved (~100%, without size-sorting process). Our method could be broadly applicable for the high-yield production of novel ultrathin nanostructures with great promise for various applications.

One-dimensional copper hydroxide nitrate nanorods and nanobelts for radiochemical applications

I report a facile wet-chemical method for the synthesis of one-dimensional copper hydroxide nitrate nanostructures in 2-propanol under solvothermal conditions. Single-crystalline nearly monodispersed copper hydroxide nitrate nanorods and nanobelts with selected breadths in the range of 100 nm to 1 μm have been successfully prepared by a solvothermal method through controlling the experimental parameters, including initial concentrations of reagents, reaction temperature, solvent and reaction time. The resultant nanorods and nanobelts were characterized using FESEM, TEM, XRD, FTIR and TGA techniques. Upon thermal calcination, the copper hydroxide nitrate nanorods and nanobelts self-assemble into one-dimensional arrays (rods, belts or tubes) of copper oxide nanoparticles. The as-prepared copper hydroxide nitrate nanorods and nanobelts were tested as ion exchangers for removal of long-lived radioactive anions such as (129)I(-) and (99)TcO(4)(-). The copper hydroxide nitrate nanorods or nanobelts were over two times more active in the removal of anion species than copper hydroxide nitrate nanoplatelets.

Facile Synthesis of Flake Copper Powder Loaded With Silver Particles

A fast and facile wet chemistry method has been developed for preparing monodispersed silver coated copper composite particles. Copper powder is coated using a solution containing [Ag (NH3)] +. The effect of the copper particle size distribution, the concentrations of [Ag (NH3)] + on composite particles conductivity were investigated. The composite particle with electric conductivity of 0.8×10-3 Ω•cm is obtained at 0.8 mol/L of Ag+ and1.0 g/L of dispersing agent. Copper powder loaded with silver particles morphologies range from individual particles to small islands, to the continuous multi-layers structure with Ag+ concentration increases.

Wet-Chemical Synthesis and Enhanced Photocatalytic Performance of ZnO/Ag Micro Hybrid Material

A new type of ZnO/Ag micro hybrid material has been fabricated by a facile wet chemical method using citrate as a crystal growth modifier. The morphology and component of ZnO/Ag hybrid material were characterized by SEM and XRD. It is shown that the platelike crystals connect together by means of embedding. The sample is composed of wurtzite ZnO and face-centered cubic Ag. The results of XPS, UV-Vis and PL spectra verify the electron transfer from Ag to ZnO. The photocatalytic test with Rhodamine B (RhB) as a representative dye pollutant shows that the ZnO/Ag hybrid material exhibits an improved photocatalytic activity.

Synthesis and photocatalytic activity of hydroxyapatite modified nitrogen-doped TiO 2

TiO 2 is a promising material as a photocatalyst for photodecomposition of hazardous organic pollutants under illumination, however, the low adsorption abilities, quantum yields and the lack of visible-light utilization hinder its practical application. In an attempt to extend light absorption of the TiO 2-based photocatalyst towards the visible light range and improve its photocatalytic activity, a new photocatalyst, HAP-modified N-TiO 2 (HAP-N-TiO 2) was synthesized by a facile wet chemical method. The properties of HAP-N-TiO 2 were investigated by X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectroscopy, nitrogen adsorption–desorption isotherm measurement, UV–visible absorption spectroscopy, and photocurrent measurement. The photocatalytic activity of the samples was evaluated by the decomposition of gaseous acetone under visible light irradiation. The research results demonstrated that 10%-HAP-N-TiO 2 sample shows the best photocatalytic activity, which is much superior to the other samples under visible light irradiation. The remarkable photocatalytic activity may arise from the synergism between adsorption on hydroxyapatite and photoactivity by titania. N-doping makes the composite also active under visible-light irradiation.

A novel and simple route to prepare a Pt nanoparticle-loaded carbon nanofiber electrode for hydrogen peroxide sensing

A facile wet-chemical method was developed to prepare a novel Pt nanoparticle-loaded carbon nanofiber (Pt/CNF) electrode. Without using any stabilizer or pretreatment procedure, large amounts of Pt nanoparticles could be well deposited on the surface of the electrospun CNF electrode at room temperature, as revealed by scanning electron microscopy (SEM). The effect of the precursor concentration on the formation of Pt catalysts was investigated to optimize the performance of the proposed hybrid electrode. When applied to the electrochemical detection of hydrogen peroxide (H 2O 2), the Pt/CNF electrode exhibited low overpotential, fast response and high sensitivity. A low detection limit of 0.6 μM with wide linear range of 1–800 μM ( R = 0.9991) was achieved at the Pt/CNF electrode, which was superior to that obtained with other H 2O 2 electrochemical sensors reported previously. In addition, the Pt/CNF electrode showed good selectivity for H 2O 2 detection in the presence of ascorbic acid (AA), acetaminophenol (AP) and uric acid (UA) under physiological pH condition. The attractive analytical performances and facile preparation method made this novel hybrid electrode promising for the development of effective H 2O 2 sensors.

Hierarchical CuO nanochains: Synthesis and their electrocatalytic determination of nitrite

Microspheres with multilevel structure are widely used as removable catalysts, adsorbents, drug carriers and imaging contrast agents due to their hierarchical porosity. In this paper a facile wet chemical method for the synthesis of hierarchically nanostructured CuO chains assembled with small nanorods is reported. The as prepared nanomaterial is characterized using X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM) and high-resolution transmission electron microscopy (HRTEM). The autocatalytic response to nitrite ions is also carried out, which exhibits a wide linear range (0.004–3.7 mM), sound sensitivity (177.9 μA mg −1 dL −1 cm −2), highly reproducible response (R.S.D. of 2.0%), and an excellent long-term stability. The good analytical performance, low cost and straightforward preparation method make this novel electrode material promising for the development of effective nitrite sensors.

Carbon-Supported Pt-Pd Alloy as a Methanol-Tolerant-Oxygen-Reduction Electro-Catalyst for DMFCs

High-performance methanol-tolerant Pt-Pd alloy on carbon with varying Pt:Pd atomic ratio of 1:1, 2:1 and 3:1 was prepared by a facile wet-chemical method and characterized by XRD, FESEM and EDX techniques. The optimum atomic weight ratio of Pt to Pd in the carbon-supported alloy catalyst as established by linear-sweep voltammetry (LSV) and cell-polarization studies is determined to be 2:1. A direct methanol fuel cell (DMFC) comprising a carbon-supported Pt-Pd(2:1) alloy (1mgPt /cm2) as the cathode catalyst delivers a peak-power density of 115 mW/cm2 at 70°C in contrast with the peak-power density value of 60mW/cm2 delivered by the DMFC with carbon-supported Pt catalyst operating under similar conditions.