This study explores the mechanical and optical properties of nanoporous copper (NPC) films dealloyed in acid and base using qualitative and quantitative measurements. Two types of NPC films (NPC 1 ...and NPC 2) were prepared by dealloying precursor films in different corrosive solutions. The films were characterized using atomic force microscopy (AFM) and scattering scanning near-field optical microscopy (s-SNOM). The AFM analysis revealed distinct nanoporous structures in both films, with NPC 2 showing larger pore sizes and the presence of copper aggregations on the surface. Rugosity measures showed that NPC 2 had higher rugosity than NPC 1 and indicated fundamental differences in the height distributions of the surface nano-topography. The Minkowski connectivity analysis highlighted differences in connectedness and topological characteristics between the two samples. The analysis of the GLCM features showed clear distinctions in ASM, Contrast, Dissimilarity, Energy, and Homogeneity between NPC 1 and NPC 2. The s-SNOM results demonstrated altered optical properties, with NPC 1 showing higher contrast at 1550 nm, while NPC 2 exhibited reversed-phase contrast at 561 nm. The phase contrast at 638 nm indicated a red-shifted optical absorption peak in NPC 2 compared to NPC 1.
Precise deuterium incorporation with controllable deuterated sites is extremely desirable. Here, a facile and efficient electrocatalytic deuterodehalogenation of halides using D2O as the deuteration ...reagent and copper nanowire arrays (Cu NWAs) electrochemically formed in situ as the cathode was demonstrated. A cross‐coupling of carbon and deuterium free radicals might be involved for this ipso‐selective deuteration. This method exhibited excellent chemoselectivity and high compatibility with the easily reducible functional groups (C=C, C≡C, C=O, C=N, C≡N). The C−H to C−D transformations were achieved with high yields and deuterium ratios through a one‐pot halogenation–deuterodehalogenation process. Efficient deuteration of less‐active bromide substrates, specific deuterium incorporation into top‐selling pharmaceuticals, and oxidant‐free paired anodic synthesis of high‐value chemicals with low energy input highlighted the potential practicality.
Cu nanowire arrays formed in situ are efficient catalysts for controllable deuteration of halides using D2O as a cheap and safe deuterated donor. A cross‐coupling of carbon and deuterium free radicals might be involved in this reaction. High compatibility with easily reducible functional groups, one‐pot C−H to C−D transformation, and paired synthesis of valuable chemicals at both electrodes showed the potential utility.
We report on the template electrodeposition of different copper/copper oxide nanoparticles on pencil graphite lead substrate using ionic and neutral surfactant templates. Physical structure and ...electrochemical properties of the modified electrodes were shown to be influenced by the nature of surfactant template. These copper modified pencil graphite electrodes exhibited very good catalytic activity towards hydrogen peroxide reduction reaction, which could be used for the sensitive and selective detection of H2O2. A maximum sensitivity of ca. 158 µA/mM/cm2, lower limit of detection (LOD) of 0.35 ± 0.04 µM, response time of <2 seconds and a linearity in wide range of concentration from 1 µM to 13 mM were observed. These electrodes were highly selective towards hydrogen peroxide with little interference from glucose, fructose, ascorbic acid, dopamine, uric acid, urea, chlorides, nitrates and sulphates even at 100 fold higher concentrations of the interfering species compared to H2O2 concentration. Practical feasibility of the sensor was demonstrated by detecting H2O2 in human blood serum and milk samples with good recovery. Our methodology enables one to prepare the electrode within two minutes and to complete the analysis within another 60 seconds, enabling the quantitative detection of hydrogen peroxide in less than five minutes using a freshly prepared, cost-effective electrode without any complicated procedure.
Nanocrystalline copper nanoparticles with varying morphology, nanocubes (∼50 nm), nanorods (diameter of ∼3 nm and length of ∼50 nm) and nanospheres (5 nm) have been synthesized using the ...microemulsion method and subsequent treatment at 400 °C in hydrogen atmosphere. The role of concentration in the self-assembly of nanoparticles in varying dimensionality has been brought out in this study. Copper nanoparticles are known to be efficient electro-catalysts for a variety of reactions. In addition, the ability of copper catalyst to generate hydrogen and oxygen in electrochemical reactions provided the impetus to understand size and shape dependence of such electro-catalytic reactions of copper in nanocrystalline form. Cube-shaped nanoparticles show significantly high hydrogen and oxygen evolution efficiencies compared to the nanorods and spherical nanoparticles. The nanospheres show higher hydrogen and oxygen evolution efficiencies than the nanorods.
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Metallic copper nanostructures were synthesized in porous glass membranes by reduction of two-dimensional copper(II) oxide layers. The frequency and temperature dependences of the electrical ...conductivity, combined with X-ray diffraction data, evidence the fixation of a 2D copper layer on the walls of the through channels of the support. The possibility of formation of planar metallic structures depends on the degree of surface coverage by the oxide precursor. The amount of copper resulting from copper oxide reduction in porous glass determines its resistance to oxidation in air.
We report on the facile electrodeposition of copper nanostructures on graphite lead substrate using anionic, cationic and non-ionic surfactant templates. Physical and electrochemical characterisation ...confirmed the influence of templates on the morphology and electrochemical catalytic activities of the copper electrodeposits. These electrodes were shown to be excellent electrocatalyst for the fast detection of hydrogen peroxide. A maximum sensitivity of 951.45μA/mM/cm2, LOD of 0.43μM, response time of <1s and a linearity in wide range of concentration from 1μM to 5mM were observed when sodium dodecyl sulfate was used as the template. While most of the previously reported sensors have advantages either on the facile synthesis or fast detection of analyte, our methodology enables preparation of the electrode within 120s and analysis within another 60s without any complicated procedure, thereby demonstrating one of the fastest and cost-effective method for hydrogen peroxide analysis with high sensitivity and selectivity.
•A facile method for the preparation of copper nanostructures is provided using template electrodeposition.•The proposed electrochemical H2O2 sensor need <5 minutes for preparation-cum-analysis, demonstrating an ultra fast method.•The sensor exhibits very high sensitivity of 951.45 μA/mM/cm2 and excellent responce time of less than 1s.•Sensor performance was evaluated in PBS and the practical application was demonstrated in human blood serum and milk samples.
Copper nanostructures were synthesized using (KI)
x
(CuI)
1−
x
films under a direct current electric field (DCEF) treatment. The influence of the reaction temperature and the molar ratio between KI ...and CuI on the morphology and the diameter of the product were investigated. It was found that when the molar ratio was 0.05:0.95, single-crystalline copper nanowires with a face-centered cubic (fcc) structure were synthesized, and the diameter of the nanowires increased with the increasing reaction temperature. When the molar ratio increased to 0.3:0.7 and 0.35:0.65, copper nanorods and nanoparticles were obtained, respectively.
In the two metal–zeolite systems (Ag–erionite and Cu–erionite), we demonstrate the optical features of metal species incorporated. These two systems are very different in the optical appearance, but ...rather similar in X-ray diffraction (XRD) patterns of the reduced forms. Ag8 clusters within the regular intra-crystalline erionite voids provide the pronounced absorption peaks in UV; other species are associated with the silver nanoparticles ordered in the erionite matrix. In the case of copper, the plasmon resonance band is developed by the metal nanoparticles. No any additional ordering was observed for copper–erionite samples.
The electrochemical multiplexed sensing has been gaining attention since this approach allows one to merge several sensing areas into a single compact chip. Here, we show several routes for the ...successful wafer scale microfabrication of a multiplexed silicon chip consisting of six ultramicro single gold (Au) bands (1 × 45 μm) as sensing electrodes. We have also developed a simple, low cost method to increase the roughness of the ultramicro sensing electrode surfaces (the roughness factor –RMS– increased from 1.6 to 2.3 nm) with high reproducibility via an electrochemical potassium hydroxide treatment. We show the application the fabricated ultramicro sensing surface via hydrogen bubble template to achieve copper foam (CuFoam) depositions. The resulting CuFoam microarchitectures were used to demonstrate a multi-purpose multiplexed platform, which was capable of catalysing glucose from serum samples and from river water to determine the chemical oxygen demand (COD). We also show the impact of the CuFoam as reference electrode to improve the electroanalytical performance of the device. The resulting sensing platform showed a superior sensitivity of 121 mA/mM cm2 and a wide linear range, 0.05 mM–22.15 mM. Herein, we clearly demonstrate the intimate link between microfabrication and engineering micro-interfaces for high performance sensing tools in fields of chemical and biological applications.
Graphical Abstract image of multi-purposed multiplexed CuFoam-on-a-chip device developed for chemical or biological sensing▪
•Design and microfabrication routes of a multiplexed silicon chip.•Electrochemical and morphological characterisation of ultramicro gold surfaces (1 μm width, 45 μm length).•Increased surface roughness of ultramicro gold surface and assessment via Atomic Force Spectroscopy (AFM).•Miniaturisation of hydrogen bubble template for controlled foam deposition and the impact of the on-chip reference electrode to electroanalytical performance (copper foam as reference electrode).•Multipurpose multiplexed device: glucose detection from sterile serum or chemical oxygen demand detection from river water.
In article number 2008109, Marius Buerkle, Satoshi Kaneko, Tomoaki Nishino, and co‐workers induce the water‐splitting reaction under visible light utilizing a copper‐based single‐molecule junction. A ...product (hydrogen) and a reactant (water‐molecule) are distinguished by the single‐molecule measurements techniques based on conductance measurement, inelastic electron tunneling spectroscopy, and the first‐principles calculations.
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