Simple Wet Chemical Route Research Articles

Fabrication of Cu@Ag core–shell nanoparticles for nonlinear optical applications

We report the preparation of the core–shell structured Cu@Ag nanoparticles by a simple wet chemical route at room temperature. The surface plasmon resonance band at 405 nm is indicative of the formation of Cu@Ag nanoparticles. The powder X-ray diffraction and energy dispersive X-ray analyses were carried out to elucidate the structure and chemical composition respectively. The morphological investigations made by electron microscopes revealed that the particles are spherical in shape with core–shell structures having size of about 50 nm. The X-ray photoelectron spectroscopy was performed to elucidate surface state composition of the core–shell structured nanoparticles based on the binding energies and confirmed the formation of Cu@Ag core–shell nanoparticles. The enhanced non-linear optical response of the Cu@Ag core–shell nanoparticles was demonstrated by z-scan experiment using He–Ne laser. This report provides a simple, economical and practical technology to fabricate Cu@Ag core–shell nanoparticles with enhanced nonlinear optical properties.

Construction of CuS/Au Heterostructure through a Simple Photoreduction Route for Enhanced Electrochemical Hydrogen Evolution and Photocatalysis.

An efficient Hydrogen evolution catalyst has been developed by decorating Au nanoparticle on the surface of CuS nanostructure following a green and environmental friendly approach. CuS nanostructure is synthesized through a simple wet-chemical route. CuS being a visible light photocatalyst is introduced to function as an efficient reducing agent. Photogenerated electron is used to reduce Au(III) on the surface of CuS to prepare CuS/Au heterostructure. The as-obtained heterostructure shows excellent performance in electrochemical H2 evolution reaction with promising durability in acidic condition, which could work as an efficient alternative for novel metals. The most efficient CuS-Au heterostructure can generate 10 mA/cm2 current density upon application of 0.179 V vs. RHE. CuS-Au heterostructure can also perform as an efficient photocatalyst for the degradation of organic pollutant. This dual nature of CuS and CuS/Au both in electrocatalysis and photocatalysis has been unveiled in this study.

Synthesis of tin oxide/graphene (SnO2/G) nanocomposite and its electrochemical properties for supercapacitor applications

Tin oxide/graphene (SnO2/G) nanocomposites were prepared by a simple wet chemical route and the as prepared nanocomposites were characterized by X-ray diffraction (XRD), High Resolution Transmission Electron Microscopy (HRTEM) and Fourier transform infrared spectra (FTIR). The characterized results showed the tetragonal structure of SnO2 nanostructures on uniform distribution on graphene sheets with a particle size of ∼50nm. The reduction of graphene oxide to graphene during SnO2/G synthesis was confirmed from FTIR analysis. HRTEM analysis showed that the individual SnO2 nanoparticles deposited on graphene sheets. The electrochemical performances of SnO2/G nanocomposites towards supercapacitors were studied in 6M KOH electrolyte. A maximum specific capacitance of 818.6F/g was obtained for SnO2/G-a composite at 5mV/s scan rate suggesting that the presence of graphene matrix in SnO2 nanoparticles have enhanced the electrochemical behaviour of SnO2. The galvanostatic charge/discharge studies confirmed the good cyclic stability of the composite electrode. These excellent electrochemical properties suggested that the SnO2/G nanocomposites could be used for high energy density supercapacitor electrode materials.

Study of Gallium Oxide Nanoparticles Conjugated with β-Cyclodextrin: An Application To Combat Cancer.

Bioactive nanomaterials, namely, gallium oxyhydroxide GaO(OH), also surface-conjugated GaO(OH) with a giant sugar molecule β-cyclodextrin (CD), have been prepared through a simple wet chemical route such that the same could be suitably used in biomedical diagnostics as well as therapeutic applications. Several physical methods were used for their characterization: powder X-ray diffraction pattern of GaO(OH) NPs for their grain size determination, optical spectroscopic absorption (UV-vis and FT-IR), and fluorescence properties of these NPs to ascertain surface conjugation and also their wide band-gap properties. Besides these, morphological properties of these NPs were studied by transmission electron microscopic (TEM) investigation, justifying the elemental constitution through energy dispersive X-ray analysis (EDX). Further, biological cellular uptake of these nanoparticles have been demonstrated on cancerous HeLa cells and reported with total fetal effect after 72 h, with CD templated GaO(OH) nanoparticles, a fact that has not been reported so far.

Photo catalytic property of Pt-CuO nanostructure films prepared by wet-chemical route and photochemical deposition method

Platinum deposited CuO nanostructure films were synthesized using the wet-chemical route and photochemical deposition methods. CuO nanostructure films were grown on copper foil as substrate via a simple cost-effective wet-chemical route and used as templates for making Pt-deposited CuO samples. Platinum were deposited over the surfaces of CuO nanostructure films through a photochemical deposition process. The prepared catalysts were characterized by XRD, SEM and EDX analyses. SEM images showed formation of film containing different nano structures. The photo catalytic activity of samples was evaluated by monitoring the photo-degradation of methyl orange under visible-light irradiation. Platinum-deposited CuO (PtCuO) samples exhibit much higher visible-light-driven photo catalytic activities and the photo-stability improved significantly. Results demonstrated that the rate of degradation of the platinum-deposited CuO sample was more than 3.8 times faster than that of pure CuO nanostructures. The PtCuO catalysts prepared in this study exhibit industrially relevant interests due to the low cost, high photo catalytic activity and high stability.

Enhanced upconversion emission and magnetization in Yb3+-Er3+/Ho3+ codoped Gd2O3 nanocrystals by introducing Zn2+ ions

We observed a simultaneous enhancement of luminescence and magnetization performance in Gd2O3:Yb/Er and Gd2O3:Yb/Ho nanocrystals (NCs) after the Zn2+ ions were doped into them by a simple wet-chemical route. Besides, the enhanced upconversion (UC) emission excited by 1560 nm laser and the paramagnetic properties in Gd2O3:Yb/Er/Zn NCs were reported for the first time. This opens a new window for studying the cooperation of the ion doping effect on improving UC luminescence and magnetic properties of Gd2O3 NCs.

Efficient photo catalytic degradation of methyl orange over Ag–CuO nanostructures grown on copper foil under visible light irradiation

A novel and efficient photo catalyst was synthesized for the photo degradation of methyl orange. CuO nanostructures were grown on copper foil as substrate via a simple cost-effective wet-chemical route and used as templates for making silver-deposited CuO samples. Silver were deposited over the surfaces of CuO nanostructures through a photochemical deposition process. The resulting samples were characterized by X-ray diffraction, field emission scanning electron microscope and energy dispersive X-ray spectrometer methods. SEM images show formation of film containing sheet-like structures with thickness of about 20–50 nm and nanorod-like structures with the diameter and length of 40–70 and 100–500 nm, respectively. The photo-catalytic activity of samples was evaluated by monitoring the photo-degradation of methyl orange. Results demonstrated that the rate of degradation of the silver-deposited CuO sample was more than 4.4 times faster than pure CuO nanostructures. The Ag–CuO catalysts prepared in this study exhibit industrially relevant interests due to the low cost, high photo catalytic activity and high stability.

Synthesis of flower-like cuo hierarchical nanostructures as an electrochemical platform for glucose sensing

Flower-like CuO hierarchical nanostructures were synthesized on copper foil substrate through a simple wet chemical route in alkaline media at room temperature. SEM images collected at different reaction times revealed the transformation of initially formed Cu(OH)2 nanowires to flower-like CuO nanostructures. The hierarchical structure of the as-prepared CuO showed high electrocatalytic activity towards the oxidation of glucose making it a promising electrode material for the development of non-enzymatic glucose sensor. The amperometric sensor exhibited a wide linear response to glucose ranging from 4.5 × 10−5 to 1.3 × 10−3 mol L−1 (R2 = 0.99317) at fixed potential of 0.3 V. The detection limit was 6.9 × 10−6 mol L−1 (LOD = 3σ/s) with a sensitivity of 1.71 μA μmol−1 cm−2. Moreover, the developed sensor offers a fast amperometric response, good selectivity and stability.

Valuation of copper oxide (CuO) nanoflakes for its suitability as an absorbing material in solar cells fabrication

Copper oxide (CuO) is a p-type semiconductor having a band gap energy of 1.5eV, which is close to the ideal energy gap of 1.4eV required for solar cells to allow the good solar spectral absorption. Present study embark on the systematic investigation of growth mechanism and correlation between the structural and optical properties of cupric oxide (CuO) nanoflakes as absorber. CuO nanoflakes were prepared via a simple one-step wet chemical route at moderate condition using hexamine as surfactant. The prepared sample is characterized by XRD Rietveld refinement, TEM-SAED pattern and FESEM with elemental mapping spectroscopy. All the characterization results revealed the obtained nanoflakes are well crystalline single phase CuO monoclinic structure. FT-IR and Raman spectrum also confirms monoclinic lattice and the CuO vibrational modes disguised the tenorite phase construction of CuO, Raman peaks shift towards lower wavenumber indicates the CuO nanoflakes are admirable material for solar cell applications. Optical absorption in IR regions projected the bandgap energy and low intense photoluminescence emissions preferred corresponding to the simple charge exchange and the light retaining capacity of the CuO nanoflakes. The high absorbance of synthesized CuO nanoflakes indicates the applicability of using it as an absorbing material in solar cells.

Thin Film ZnO Coated on FTO/TiO2 as an Anti Reflection Coatingfor EnhancingVisible Light Harversting in Dye Sensitized Solar Cells System

ZnOmaterial has unique electrical and optical properties that many important applications, including as an anti-reflection coating in dye sensitized solar cells. Flat anti-reflective coatings (ARC) made of ZnO on top to improve the optical properties of the coating. In this study, ZnO nanoparticle were coated with TiO2 nanolayers by a simple wet chemical route. TiO2 nanorods coated ZnO nanoparticle was synthesized by two step i.e. (1) base hydrolysis and polymerization of TiO2 (2) ZnO nanoparticle were coated with a TiO2 layer. The TiO2 coated ZnO prepared was characterized by X-ray diffraction (XRD), Reflectance spectroscopy, SEM and TEM. ZnO annealed at a temperature of 400oC have the greatest crystal size than annealedat a temperature of 500°C and 600°C. While, the Reflectance (%R)properties shows that the higher annealing temperature of ZnO preparations, the higher of %R value of ZnO thin layer. The ZnO prepared by annealed at 400oCgain a good performance of the lowest reflectance value. The difference properties are due to differences of light scattering resulting from the crystal size effect. The crystals size that have a good performance as an anti-reflection is around 20nm, result study of ZnOannealed at 400°C. TEM nanograph shows that the synthesized ZnO have spherical morphology. The optimum performance ofDSSCs was conducted using the photoanode ZnO-coated TiO2at present 10%APTMS as surface modifier anchor dye group. Bythe addition of ARC we have been capable improve cell performance so that cells achieve an efficiency of 1.13%.

Facile preparation of β-/γ-MgH₂ nanocomposites under mild conditions and pathways to rapid dehydrogenation.

A magnesium hydride composite with enhanced hydrogen desorption kinetics can be synthesized via a simple wet chemical route by ball milling MgH2 with LiCl as an additive at room temperature followed by tetrahydrofuran (THF) treatment under an Ar atmosphere. The as-synthesized composite comprises ca. 18 mass% orthorhombic γ-MgH2 and 80 mass% tetragonal β-MgH2 as submicron-sized particles. The β-/γ-MgH2 nanocomposite exhibits a dehydrogenation capacity of 6.6 wt% and starts to release hydrogen at ∼260 °C; ca. 140 °C lower than that of commercial MgH2. The apparent activation energy for dehydrogenation is 115 ± 3 kJ mol(-1), which is ca. 46% lower than that of commercial MgH2. Analysis suggests that the meta-stable γ-MgH2 component either directly dehydrogenates exothermically or first transforms into stable β-MgH2 very close to the dehydrogenation onset. The improved hydrogen release performance can be attributed both to the existence of the MgH2 nanostructure and to the presence of γ-MgH2.

Synthesis and characterization of DNA fenced, self-assembled SnO2 nano-assemblies for supercapacitor applications.

Self-assembled, aggregated, chain-like SnO2 nano-assemblies were synthesized at room temperature by a simple wet chemical route within an hour in the presence of DNA as a scaffold. The average size of the SnO2 particles and the chain diameter were controlled by tuning the DNA to Sn(ii) molar ratio and altering the other reaction parameters. A formation and growth mechanism of the SnO2 NPs on DNA is discussed. The SnO2 chain-like assemblies were utilized as potential anode materials in an electrochemical supercapacitor. From the supercapacitor study, it was found that the SnO2 nanomaterials showed different specific capacitance (Cs) values depending on varying chain-like morphologies and the order of Cs values was: chain-like (small size) > chain-like (large size). The highest Cs of 209 F g(-1) at a scan rate of 5 mV s(-1) was observed for SnO2 nano-assemblies having chain-like structure with a smaller size. The long term cycling stability study of a chain-like SnO2 electrode was found to be stable and retained ca. 71% of the initial specific capacitance, even after 5000 cycles. A supercapacitor study revealed that both morphologies can be used as a potential anode material and the best efficiency was observed for small sized chain-like morphology which is due to their higher BET surface area and specific structural orientation. The proposed route, by virtue of its simplicity and being environmentally benign, might become a future promising candidate for further processing, assembly, and practical application of other oxide based nanostructure materials.

Enhanced Li- and Na-storage in Sb-Graphene nanocomposite anodes

Antimony-graphene nanocomposite (Sb-GNP) was prepared from commercially available graphene nanoplatelets (GNPs) by a simple wet-chemical route at room temperature, and systematically investigated as an anode material for both lithium- and sodium-ion batteries (LIBs and NIBs). The microstructural features of Sb-GNP, and of pure Sb nanoparticles prepared without addition of GNPs, were characterized using X-ray diffraction, field-emission scanning electron microscopy, and high-resolution transmission electron microscopy. The successful formation of a nanocomposite structure was observed for Sb-GNP; the Sb nanoparticles are well dispersed and anchored on graphene nanoplatelets without significant aggregation of Sb nanoparticles, in contrast to the pure Sb nanoparticles. Furthermore, galvanostatic studies revealed that Sb-GNP displays better Li- and Na-storage performance than the pure Sb nanoparticles when utilized as an anode material. The enhanced electrochemical performance can be attributed to the effects of nanocomposite formation with GNPs.

Photoluminescent properties of SPAN-80 coated intrinsic and extrinsic ZnO nanostructures

Semiconductor nanostructures catch the attention due to morphology tunable properties. SPAN-80-Capped intrinsic and extrinsic ZnO nanostructures have been synthesized by the simple wet-chemical synthesis route. Structural behavior (morphology and crystallography) and photoluminescence performance of synthesized nanomaterials have been explored as a function of variable SPAN-80 concentration (0.05–0.125%). Crystallographic studies reveal that the prepared products possess wurtzite structure. Electron microscopy infers that the quantum dots are bunched together to form multifaceted morphology for 0.05% SPAN-80 concentration, whereas rectangular shape has been observed for extreme capping concentration. Photoluminescence properties have affected drastically with the introduction of SPAN-80 during the precipitation reaction. Photoluminescent properties of the synthesized nanostructures are strongly dependent on SPAN-80 concentration. Augmentation of capping concentration from 0.05% to 0.075% diminishes the luminescence quantum yield due to increased surface passivation whereas further addition of capping agent beyond the optimum capping concentration (0.075%) enhances the PL intensity due to increased energy transfer from capping shell to the nanostructure core.

Synthesis and characterization of flower-like ZnO structures and their applications in photocatalytic degradation of Rhodamine B dye

We have synthesized ZnO nanoflakes (ZnO-NFs) assembled flower-like structures through simple wet chemical route without using any growth directing agent. The ZnO NFs have been characterized in terms of morphological, structural, and optical properties by field emission-scanning electron microscope (FE-SEM), X-ray diffraction (XRD), Raman, Fourier transform infrared (FTIR) and ultraviolet–visible (UV–Vis) spectroscopy. FE-SEM images show the nanoflakes assembled flower-like morphology of the as-prepared sample. XRD and Raman studies confirm that it has stable wurtzite structure. The formation of ZnO-NFs is also confirmed by the bond corresponding to metal-oxygen vibration in the FTIR spectrum at ~460 cm−1. The UV–Vis absorption spectrum of synthesized sample gives the optical band gap value of 3.2 eV. The photocatalytic activity of the ZnO-NFs is evaluated by observing their role in the photocatalytic degradation of Rhodamine B (RhB) dye. Results show that ZnO-NFs are capable of working efficiently for the degradation of RhB dye.

Synthesis and luminescence properties of RE3+ (RE = Yb, Er, Tm, Eu, Tb)-doped Sc2O3 microcrystals

Scandium oxide (Sc2O3) microcrystals with controlable morphology and luminescence have been synthesized through a simple wet-chemical route for the first time. By changing the precipitants, Sc2O3 microcrystals with different shape and size are achieved. Efficient luminescence emissions have also been reported. Yb3+-Er3+, Yb3+-Tm3+ codoped Sc2O3 microcrystals can emit bright upconversion (UC) red and blue light with high purity, respectively, while Eu3+, Tb3+-doped Sc2O3 microcrystals can exhibit intense downconversion (DC) red light and green light. Research about the properties of Sc2O3 microcrystals opens a window of new and efficient luminescence hosts for further fundamental research and various applications.

Gold–platinum bimetallic nanotubes templated from tellurium nanowires as efficient electrocatalysts for methanol oxidation reaction

In this paper, gold–platinum (Au–Pt) bimetallic nanotubes with different Au/Pt ratio are successfully synthesized through a simple wet-chemical reduction route in which tellurium (Te) nanowires serve as both sacrificial template and reducing agent. The hollow nanostructure of Au–Pt nanotubes is formed due to Kirkendall effect. The as-prepared Au–Pt nanotubes can be applied as catalyst for methanol oxidation reaction, and the results indicate that the Au–Pt nanotubes with an Au/Pt ratio of 1:1 show the best electrochemical catalytic performances. Furthermore, the catalytic activity of the Au–Pt nanotubes is also better than Pt nanotubes and commercial Pt/C catalyst.

Analysis of the dielectric relaxation and ac conductivity behavior of polyvinyl alcohol‐cadmium selenide nanocomposite films

We adopt an analytical approach to study the dielectric relaxation and ac conductivity behavior of the polyvinyl alcohol (PVA) ‐ Cadmium Selenide (CdSe) nanocomposite films in the frequency range 100 Hz ≤ f ≤ 1 MHz and in the temperature range 298 K ≤ T ≤ 420 K. The CdSe nanoparticles are synthesized via a simple wet chemical route and are then impregnated into the polyvinyl alcohol matrix by 0.5 wt%, 1 wt%, and 4 wt%. About 1.7 times increase in effective permittivity (at 100 KHz) for the 4 wt% nanoparticle impregnated sample is observed from the analysis of the dielectric reinforcement function, which is attributed to the occurrence of interfacial polarization. It is found that the Cole‐Cole model with a dc conductivity correction term can well fit the permittivity data. We have found that the dielectric relaxation time increases with increase in nanoinclusion into the matrix but decreases with increase in temperature. However, the space charge carrier conductivity and free charge carrier conductivity increase either with increase in nano inclusions or with increase in temperature. AC conductivity behavior have been analyzed considering the Jonscher power law and Dyre's random free energy barrier model, which reveals lowering of the maximum barrier height and correlated barrier hopping as the prevalent charge transport mechanism for the nanocomposites. Electric modulus study indicates similar conductivity relaxation dynamics for the nanocomposites but the responses deviate appreciably from the simulated ideal Debye responses. POLYM. COMPOS., 38:287–298, 2017. © 2015 Society of Plastics Engineers

SILAR coated Bi2S3 nanoparticles on vertically aligned ZnO nanorods: Synthesis and characterizations

Simple and inexpensive wet chemical route, namely successive ionic layer adsorption and reaction (SILAR) is demonstrated to coat the inorganic semiconducting Bi2S3 nanoparticles (NPs) at room temperature on chemical bath deposited vertically aligned ZnO nanorods (NRs). The films were characterized by X-ray diffraction (XRD), UV–vis spectroscopy, field emission scanning electron microscopy (FE-SEM), energy dispersive X-ray analysis (EDX), Raman spectroscopy and surface profiler in order to confirm the crystal structure, optical properties, surface morphology, elemental compositions and film thickness. Finally, the solar cell device was formed by using Bi2S3 coated ZnO NRs as photoanode, liquid electrolyte as hole conducting media and platinum (Pt) as a back contact. The power conversion efficiency (η) of 0.025% under illumination of simulated sunlight (AM 1.5G, 100mW/cm2) was observed.

UV-A light-induced photodegradation of Acid Blue 113 in the presence of Sm-doped ZnO nanostructures

In this report, optical and photocatalytic degradation of Acid Blue 113 (AB 113) has been investigated in an aqueous heterogeneous media containing pure and Sm-doped ZnO nanostructures which were prepared by a simple wet chemical route. X-ray diffraction measurement confirmed that the prepared nanostructures were in hexagonal wurtzite structure and the dopant Sm ion was incorporated into the Zn lattice. Interesting morphological changes involving a nanosheet-star-spherical transition were observed upon Sm doping and annealing, which were identified through transmission electron microscope. Optical absorption measurements showed an exciton absorption band and a band gap narrowing with respect to the Sm concentrations. The photodegradation of Acid Blue 113 under UV-A radiation by using pure and Sm-doped ZnO nanostructures showed that samarium played an important role in the significant improvement of the photodegradation efficiency and the optimum amount of Sm ion was found to be 1 mmol %. Further, the possible degradation mechanism was proposed herein.