Copper Alloy Nanoparticles Research Articles

Palladium–Copper Alloy Nanoparticles Supported on Carbon Nitride Nanosheets as a Photocatalyst for Degradation of Ciprofloxacin

Palladium–Copper Alloy Nanoparticles Supported on Carbon Nitride Nanosheets as a Photocatalyst for Degradation of Ciprofloxacin

Synthesis of Bimetallic Silver and Copper Alloy Nanoparticles Embedded with Styrene-Methyl Methacrylate Copolymer Nanosphere (SMMA@Ag-Cu) as a Potential Surface Enhanced Raman Scattering (SERS) Substrate

Synthesis of Bimetallic Silver and Copper Alloy Nanoparticles Embedded with Styrene-Methyl Methacrylate Copolymer Nanosphere (SMMA@Ag-Cu) as a Potential Surface Enhanced Raman Scattering (SERS) Substrate

Enhanced ammonia sensitivity electrochemical sensors based on PtCu alloy nanoparticles in-situ synthesized on carbon cloth electrode

The alloying of Pt with transition metals is significant in boosting the performance of Pt-based electrochemical sensors. In this paper, Platinum and copper alloy nanoparticles (PtCu NPs) were in-situ loaded on carbon cloth (CC) by electrochemical deposition to obtain a self-supported electrode (PtCu-CC) for electrochemical detection of ammonia. The alloying of Pt and Cu reduced the crystal lattice spacing of Pt and improved the catalytic performance of ammonia. Therefore, the PtCu-CC electrode displayed visibly enhanced ammonia detection performance compared with the Pt-CC electrode and commercial Pt electrode. The linear range for ammonia determination was from 0.5 to 40 and 40–500 μM, and the sensitivity of the Pt7Cu1-CC sensor was 9.5 μA μM−1 cm−2 and 0.778 mA lg μM−1 cm−2, respectively. The detection limit was 8.6 ± 0.32 nM, and the quantification limit was 28.67 ± 0.73 nM. The developed sensor shows good anti-interference capability, reproducibility and stability; in addition, it exhibited good capacity in the actual water sample test. PtCu alloy nanoparticles were applied to ammonia detection in water, which may broaden the ways of ammonia detection in water.

Nickel–Copper Alloy Nanoparticles Embedded in N-Doped Porous Carbon Nanosheets for Supercapacitors and Hydrogen Evolution Reaction

Nickel–Copper Alloy Nanoparticles Embedded in N-Doped Porous Carbon Nanosheets for Supercapacitors and Hydrogen Evolution Reaction

Platinum–copper alloy nanoparticles armored with chloride ion transporter to promote electro-driven tumor inhibition

The induction of oxidative species, driven by oscillating electric field (E), has recently emerged as an effective approach for tumor inhibition, so-called electrodynamic therapy (EDT). While it offers a series of advantages attracting considerable attention, the fundamental mechanism and improvement strategies for EDT approach are being endeavored extensively with the aid of new material explorations. An interesting phenomenon observed in early studies is that the on-site concentration of chloride ion is highly favored for the induction of oxidative species and the efficacy of tumor inhibition. Following this discovery ignored previously, here for the first time, fine Pt/Cu alloy nanoparticles (PtCu3 NPs) are integrated with chloride ion transporter (CIT) for EDT-based combinational therapy. In this system, while PtCu3 NPs induce oxidative species under an electric field, it also effectively transforms endogenous H2O2 into •OH and consumes intracellular glutathione (GSH). More importantly, with the aid of CIT, PtCu3-PEG@CIT NPs promote the intracellular concentration of chloride ion (Cl−) by transporting extracellular Cl−, facilitating the generation of oxidative species considerably. Meanwhile, CIT delivered intracellularly increases lysosomal pH, leading to the disruption of cellular autophagy and weakening the treatment resistance. In consequence, significant tumor inhibition is enabled both in vitro and in vivo, due to the combination of unique characteristics offered by PtCu3-PEG@CIT.

Monodisperse ruthenium[sbnd]copper alloy nanoparticles decorated on reduced graphene oxide for dehydrogenation of DMAB

In this study, we report a superior dehydrogenation catalyst for dimethylamine borane, which exhibited one of the best catalytic activities. The newly formed catalyst system contains well dispersed ruthenium-copper nanomaterials on reduced graphene oxide (3.86 ± 0.47 nm), which was prepared by using the ultrasonic double reduction technique. The characterization of monodisperse ruthenium-copper alloy nanoparticles was performed using some advanced analytical methods such as TEM, HRTEM, XPS, Raman spectroscopic analysis. The experiments results revealed that the monodisperse ruthenium-copper alloy catalyst (RuCu@rGO) has one of the highest catalytic activity compared to previous studies, having a high turnover frequency value (256.70 h−1). The detailed kinetic parameters such as activation energy, enthalpy, and entropy values were also calculated for the dehydrogenation of dimethylamine borane at room temperature. Also, the results showed that the monodisperse RuCu@rGO catalyst has high durability and reusability as retained its 81% initial catalytic activity even after 4th runs for the dehydrogenation of dimethylamine borane.

Gold copper alloy nanoparticles (Au-Cu NPs) modified electrode as an enhanced electrochemical sensing platform for the detection of persistent toxic organic pollutants

The present study describes the development of an efficient electrochemical sensing platform based on gold-copper alloy nanoparticles (Au-Cu NPs) used for detection of nitro aromatic toxins. The redox behaviour of four nitro functional group containing aromatic compounds was studied on five different NPs based sensors by square wave and differential pulse voltammetric techniques. Under optimized conditions, these functional group containing aromatic compounds exhibited reduction peaks within the range of −785mV to −881mV (versus Ag/AgCl) at the alloy NPs based modified electrodes. The results revealed that Au-Cu (1:3) modified Glassy Carbon Electrode (Au-Cu(1:3)/GCE) exhibit ultrahigh-sensitivity for the detection of 2-amino-4-nitrophenol, 4-nitrophenol, 2-methyl-3-nitrophenyl acetic acid and 3-nitrotoulene. The performance of the developed method was further examined for the determination of 2-amino-4-nitrophenol in drinking and tap water samples. UV/Vis spectroscopy was performed to study the catalytic reduction of 2-amino-4-nitrophenol by using Au-Cu (1:3) NPs alloy. Computational studies were carried out in order to correlate experimental findings by theoretical outcomes. We expect that these results will let the chemists to apply such sensors for various metallic, organic and organometallic toxins with slight modification.

Cu4sn/C As Electrocatalyst for Selective Electrochemical Reduction of CO2 to CO: Investigation V ia on-Line Mass Spectrometry and in-Line Gas Chromatograph

Different strategies for the global climate change and the carbon dioxide (CO2) emission reduction are being the goal of many researches in recent year. The application of new technologies for direct utilization of CO2 conversion could be interesting options to recycling the molecule. The electrochemical reduction for the conversion of CO2 into added-value carbon-based products as useful fuels has been studied and it involves a new source of sustainable energy. Among the different investigated electrocatalysts, Cu is distinctive for generating hydrocarbons, mainly methane (CH4) and ethylene (C2H4) [1,2], but suffer from deactivation and low faradaic efficiency (FE). Herein, it was investigated the behavior of carbon-supported Sn-modified copper alloy nanoparticles (Cu4Sn/C) for the carbon dioxide electroreduction, and the reaction products were monitored by on-line Differential Electrochemical Mass Spectrometry (DEMS) measurements. The faradaic and ionic currents for m/z = 2 (H2) and 28 (CO), obtained during DEMS experiments of cyclic voltammetry for Cu4Sn/C, in CO2-saturated 0.1 mol L- 1 KHCO3 electrolyte, at room temperature, showed that the CO/H2 ratio for Cu4Sn/C is lower than that for Au/C (included for comparison - known as an efficient electrocatalyst for CO generation), but higher when compared to that for Sn/C (which is known to produce CO and HCOO- ion in parallel to H2 [3]) and Cu/C (for copper, the m/z = 28 has contribution from methane and ethylene fragments). Stability tests, performed via chronoamperometric curves, showed that the CO signal for Au/C decreased within few minutes, with the concomitant increase of the H2 formation, evidencing deactivation during the CO2 electroreduction. This is probably due to accumulation of adsorbed CO-like intermediates [4]. On the other hand, and interesting, the CO signal for Cu4Sn/C alloy nanoparticles remained stable. Long-term stability test, however, are still necessary to address this important aspect. Quantitative analyses obtained by using in-line gas chromatography have shown FE for CO production of 23 and 13 % for Au/C and Cu4Sn/C, respectively. Therefore, the results obtained herein revealed that CO can be produced by using the non-noble metal-based Cu4Sn/C electrocatalyst. Although this material presented lower faradaic efficiency than that for Au/C, the electrochemical and DEMS measurements demonstrated higher stability for CO generation during the electrochemical polarization. Acknowledgements The authors thank FAPESP (2014/26699-3, 2013/16930-7 and 2016/13323-0) and CNPq for financial support.

Inside Back Cover: Lead–Sulfide–Selenide Quantum Dots and Gold–Copper Alloy Nanoparticles Augment the Light‐Harvesting Ability of Solar Cells (ChemPhysChem 7/2017)

Inside Back Cover: Lead–Sulfide–Selenide Quantum Dots and Gold–Copper Alloy Nanoparticles Augment the Light‐Harvesting Ability of Solar Cells (ChemPhysChem 7/2017)

Lead–Sulfide–Selenide Quantum Dots and Gold–Copper Alloy Nanoparticles Augment the Light‐Harvesting Ability of Solar Cells

Lead-sulfide-selenide (PbSSe) quantum dots (QDs) and gold-copper (AuCu) alloy nanoparticles (NPs) were incorporated into a cadmium sulfide (CdS)/titanium oxide (TiO2 ) photoanode for the first time to achieve enhanced conversion of solar energy into electricity. PbSSe QDs with a band gap of 1.02 eV extend the light-harvesting range of the photoanode from the visible region to the near-infrared region. The conduction band (CB) edge of the PbSSe QDs is wedged between the CBs of TiO2 and CdS; this additional level coupled with the good electrical conductivity of the dots facilitate charge transport and collection, and a high power conversion efficiency (PCE) of 4.44 % is achieved for the champion cell with the TiO2 /PbSSe/CdS electrode. Upon including AuCu alloy NPs in the QD-sensitized electrodes, light absorption is enhance by plasmonic and light-scattering effects and also by the injection of hot electrons to the CBs of the QDs. Comparison of the incident photon-to-current conversion efficiency enhancement factors in addition to fluorescence decay and impedance studies reveal that the PbSSe QDs and AuCu alloy NPs promote charge injection to the current collector and increase the photogenerated charges produced, which thus enables the TiO2 /PbSSe/CdS/AuCu cell to deliver the highest PCE of 5.26 % among all the various photoanode compositions used.

Cancer Therapy: Dendritic Platinum–Copper Alloy Nanoparticles as Theranostic Agents for Multimodal Imaging and Combined Chemophotothermal Therapy (Adv. Funct. Mater. 33/2016)

Cancer Therapy: Dendritic Platinum–Copper Alloy Nanoparticles as Theranostic Agents for Multimodal Imaging and Combined Chemophotothermal Therapy (Adv. Funct. Mater. 33/2016)

Palladium and palladium–copper alloy nano particles as superior catalyst for electrochemical oxidation of methanol for fuel cell applications

Monometallic Pd, Cu and bimetallic Pd98Cu2, Pd94Cu6, Pd86Cu14 alloy nano particles with small average particle diameter (6–10 nm) are synthesised by facile single pot hydrothermal reduction with hydrazine solution at 75 °C in absence of any special capping agent. Synthesized nano-materials are characterized by X-ray, electron diffraction, different microscopic and electro-analytical studies. Graphite supported bimetallic PdxCu100-x alloy unlike mixed nano particles show synergistic and enhanced electro catalytic activity towards oxidation of methanol in alkali. The maximum specific peak current of 987 mA mg−1 and equilibrium exchange current of 5 × 10−6 mA mg−1 of Pd obtained for Pd94Cu6 alloy in the present work are much better than the corresponding values reported for PdxCu100-x composite and alloy materials. Cyclic voltammograms of possible intermediates like formaldehyde as well as sodium formate and ex-situ FTIR and chromatographic studies of reaction products reveal that Cu accelerates formation of formate rather than carbonate elucidating the plausible mechanism of the reaction.

Dendritic Platinum–Copper Alloy Nanoparticles as Theranostic Agents for Multimodal Imaging and Combined Chemophotothermal Therapy

Theranostic nanoparticles that possess multiple diagnostic modalities and allow spatiotemporally controlled therapies can significantly improve therapeutic outcomes and reduce adverse effects. Here, an intelligent and biocompatible theranostic formulation is developed based on dendritic platinum–copper alloy nanoparticles (DPCN) for cancer therapy. DPCN have excellent photothermal effect, and can load anticancer drugs such as doxorubicin in their porous structure and release the loaded drugs in response to near infrared light or moderate acidic stimulus. They also inherently have multimodal imaging modalities. Upon the guidance of photoacoustic imaging, DPCN‐mediated photothermal treatment efficiently inhibits tumor growth in vivo. Furthermore, doxorubicin‐loaded DPCN completely suppress the tumor growth even under a low treatment temperature, which avoids hypothermia‐induced damage to normal tissues. Our study develops an excellent theranostic nanoparticle with inherent multimodal imaging and therapeutic modalities for chemophotothermal cancer therapy.

Co–Cu alloy nanoparticles decorated TiO2 nanotube arrays for highly sensitive and selective nonenzymatic sensing of glucose

A nonenzymatic glucose sensor was fabricated by electrodepositing cobalt rich cobalt–copper alloy nanoparticles (Co–CuNPs) on vertically aligned TiO2 nanotube (TDNT) arrays. For this, TDNT arrays with tube diameter of 60nm were synthesized by electrochemical anodization. The composition of the electrodeposited alloy was optimized based on the electrocatalytic activity towards glucose oxidation. This is achieved by controlling the concentration of electrolyte and time of deposition. Chemical composition of the optimized Co–Cu alloy nanoparticles is determined to be Cu0.15Co2.84O4 with fcc crystalline structure. The sensor showed two linear range of detection with high sensitivity of 4651.0μAmM−1cm−2 up to 5mM and 2581.70μAmM−1cm−2 from 5mM to 12mM with a lower detection limit of 0.6μM (S/N=3). The sensor is highly selective to glucose in the presence of various exogeneous and endogeneous interfering species and other sugars. The response of the sensor towards blood serum was in good agreement with that of commercially available glucose sensors.

The synthesis and characterization of nickel–copper alloy nanoparticles with a narrow size distribution using sol–gel synthesis

Nickel–copper (NiCu) alloy magnetic nanoparticles with a narrow size distribution were prepared by reducing a Ni, Cu-oxide mixture in a silica matrix, obtained with a sol–gel method. In order to obtain the NiCu nanoparticles, the silica matrix was treated with an etching solution in an argon atmosphere. By selecting the nominal NiCu alloy composition of 67.5:32.5, a Curie temperature close to 65°C was achieved. The nanoparticles were superparamagnetic with a magnetization of 8emu/g at 293K and exhibited a significant heating ability in an alternating magnetic field. The simplicity of the synthesis allows the preparation of NiCu alloy nanoparticles on a large scale. The method could also be used for the preparation of other mixed-alloy nanoparticles.

Nonenzymatic glucose sensor based on gold–copper alloy nanoparticles on defect sites of carbon nanotubes by spontaneous reduction

Gold (Au) and copper (Cu) alloy catalysts were deposited on the defect sites of carbon nanotubes by spontaneous reduction among AuCl 4 −, Cu 2+ and oxygen-containing functional groups. Compared with AuCu alloy catalysts prepared by adsorption methods and electrochemical deposition methods, AuCu alloy catalysts show excellent catalytic ability to glucose by spontaneous reduction. The linear range of nonenzymatic sensors that were prepared by spontaneous reduction for glucose detection is 0.08–9.26 mM, and detection limit is 4 μM. In addition, there are high sensitivity (22 μA mM −1), reproducibility (96%) and stability (95% after 60 days). Selectivity of this nonenzymatic sensor for ascorbic, uric acid and acetaminophen was also obtained.