Hydrothermal Syntheses of CuO,CuO/Cu2O,Cu2O,Cu2O/Cu and Cu Microcrystals Using Ionic Liquids

In this paper, CuO, CuO/Cu₂O, Cu₂O, Cu₂O/Cu and Cu microcrystals were synthesized via a hydrothermal method by mixing Cu(NO₃)₂·3H₂O and NaOH together in the presence of an ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate([BMIM]BF₄) or 1-butyl-3-methylimidazolium chloride([BMIM]Cl). The structures and the morphologies of the obtained products were characterized by means of X-ray diffractometer(XRD), field-emission scanning electron microscopy/energy-dispersive spectroscopy(FESEM/EDS), transmission electron microscopy/selected area electron diffraction(TEM/SAED) and Raman spectroscopy. The result of XRD indicates that Cu₂O and Cu microcrystals are cubic phase and the Raman spectra confirm the presence of carbon. The results of FESEM and TEM images show Cu₂O microcrystals as rule cubes of 2 μm in length and Cu particles of 5 μm in diameter. According to the difference between crystal structures, bi-component and single component products were synthesized by adjusting the reaction conditions. A possible formation mechanism of Cu₂O and Cu was proposed in[BMIM]BF₄.     

Cu2O/CuO Electrocatalyst for Electrochemical Reduction of Carbon Dioxide to Methanol

Herein, we report the controlled and direct fabrication of Cu₂O/CuO thin film on the conductive nickel foam using electrodeposition route for the electrochemical reduction of carbon dioxide (CO₂) to methanol. The electrocatalytic reduction was performed in CO₂ saturated aqueous solution consisting of KHCO₃, pyridine and HCl at room temperature. CO₂ reduction was carried out at a constant potential of −1.3 V for 120 min to study the electrochemical performance of the prepared electrocatalysts. Cu₂O/CuO shows better electrocatalytic activity with highest current density of 46 mA/cm². The prepared catalyst can be an efficient and selective electrode for the production of methanol.     

Improved electrochemical performances of core-shell Cu2O/Cu composite prepared by a simple one-step method

Core-shell Cu₂O/Cu composites were successfully prepared by over-reduction of aqueous CuSO₄ with hydrazine hydrate as reductant. Field emission scanning electron microscopy (SEM) and high resolution transmission electron microscopy (HRTEM) clearly illuminate that the core is Cu₂O with 400 nm in diameter, and the shell is Cu with about 50 nm in thickness. The core-shell Cu₂O/Cu exhibited weaker polarization and higher coulombic efficiency than pure octahedral Cu₂O, especially in the initial stage of cycles. After 50 cycles, the reversible capacity of Cu₂O/Cu (360 mAh g^?1) was much higher than that of pure Cu₂O (160 mAh g^?1). The improvement of electrochemical properties is attributed to the core-shell structure of Cu₂O/Cu and the catalytic effect of Cu on the decomposition of Li₂O during the charging process.     

Derivatives (Cu/CuO,Cu/Cu2O,and CuS) of Cu superstructures reduced by biomass reductants

Metallic Cu is considered as the promising functional material owing to its high conductivity and harmlessness. Here, metallic Cu which presents a unique interconnected and continuous structure (Cu superstructure) is prepared using Magnolia grandiflora leaves as the biomass reductant, a green process which avoided the release of harmful gases and massive energy consumption. What's more, Cu/CuO, Cu/Cu₂O, and CuS nanosheets with different sizes were fabricated using Cu superstructure as the substrate via facile methods, and the morphology is regulated by controlling the relevant factors. The electrochemical sensors based on the three derivations were fabricated to study the sensing performance of glucose. The unique structure of nanosheets encapsulating Cu superstructure guarantees the excellent conductivity of Cu/CuO and Cu/Cu₂O composites. Moreover, the electrochemical stability is improved owing to the nanosheet protective layer. Although no metallic Cu was maintained in CuS, the integrated multilayer nanosheets endow CuS with short channels for fast interlayer electronic transmission and with structural stability.     

镍-氧化镍/铜-氧化亚铜复合纳米粒子修饰玻碳电极测定过氧化氢

在含镍离子和铜离子的溶液中用循环伏安法在玻碳电极(GCE)表面电化学沉积一层镍-氧化镍及铜-氧化亚铜纳米粒子 ( Ni /NiO、 Cu/Cu₂O),在-0.3 V电位条件下,该传感器能催化还原H₂O₂。用安培法测定H₂O₂的响应电流与浓度在2.5×10^-6 ~2.8×10^-3 mol/L范围内呈线性关系,研究了各种实验条件对H₂O₂传感器性能的影响。该传感器制作简单, 使用寿命长,在实际试样的回收率测定中,结果满意。     

锂 - 氧化铜电池及其反应机理

本文研究了Li/CuO电池和Li/CuO电池的一般放电行为,着重探讨了它们的反应机理。X射线衍射分析、ESR分析、XPS分析和循环伏安试验等结果表明,电池反应的实质是锂在正极内进行电化学嵌入反应,并在一定嵌入度后因Cu—O键断裂而析出金属铜。其化学反应式可表达为: xLi+CuO(Cu_2O)→Li_xCuO(Li_xCu_2O)(a) x_1Li+Li_xCuO(Li_xCu_2O)→ Li_(x+x_1)Cu_(1-y)O(Li_(x+x_1)CU_(2-y)O)+yCu (b) 用电化学暂态方法测得嵌入锂离子在正极内部的化学扩散系数约为2×10~(-12)cm~2·s~(-1)(室温),该值与在Li_xWO_3和Li_xTiO_2中的相近,与实际电池的放电速率是一致的。     

Electrochemical synthesis and characterization of transparent nanocrystalline Cu2O films and their conversion to CuO films

Transparent nanocrystalline Cu2O films (Eg = 2.6 eV) were electrodeposited from a dimethyl sulfoxide medium; these films exhibit interesting optical and photoelectrochemical properties, and can be converted to transparent CuO films.     

Synthesis and supercapacitive performance of CuO/Cu2O nanosheet arrays modified by hydrothermal deposited NiOOH

Journal of Solid State Electrochemistry - Binder-free, high-performance electrode materials play a critical role for supercapacitors. In this paper, through the electrochemical anodization process,...     

CuO/Cu2O nanowire array photoelectrochemical biosensor for ultrasensitive detection of tyrosinase

Photoelectrochemical(PEC) biosensors have shown great promise in bioanalysis and diagnostic applications in recent years. In this work, the CuO/Cu_2O nanowire array(CuO/Cu_2O Nanowire) supported on copper foam was prepared as a photocathode for detection of tyrosinase though quinone-chitosan conjugation chemistry method. The in-situ generated quinones that were the catalytic product of tyrosinase acted as electron acceptors, which were captured by the chitosan deposited on the surface of the electrode. Direct immobilization of electron acceptor on the electrode surface improved the photocurrent conversion efficiency and thus sensitivity. The as-prepared biosensor can realize a rapid response in a wide linear range of 0.05 U/mL to 10 U/mL with the detection limit as low as 0.016 U/mL of tyrosinase. The current work provides a new perspective to design and develop highly sensitive and selective PEC biosensor.     

Antibacterial and photocatalytic properties of Cu2O/ZnO composite film synthesized by electrodeposition

Research on Chemical Intermediates - The high antibacterial and photocatalytic activities of Cu2O/ZnO composite films were synthesized through the electrodeposition method. The crystalline phase...     

CuO／CeO2和CuO／Al2O3催化剂的催化性能

本文以ＣＯ氧化为模式反应考察了ＣｅＯ２和Ａｌ２Ｏ３负载氧化铜催化剂的氧化活性，运用ＸＲＤ和ＴＰＲ技术研究了催化剂的还原性能和物相结构，结果表明：载体性质对负载ＣｕＯ催化剂的ＣＯ氧化活性有很大影响，ＣｕＯ／ＣｅＯ２催化剂活性明显高于ＣｕＯ／Ａｌ２Ｏ３催化剂．催化剂的还原特性随载体不同而不同．同时发现，热处理对催化剂铜物种的存在形式，晶粒大小、还原特性及其催化活性有明显影响，ＣｕＯ／Ａｌ２Ｏ３催化剂活性下降的主要因素是生成了活性较低的ＣｕＡｌ２Ｏ４相，而ＣｕＯ／ＣｅＯ２催化剂活性下降是由于ＣｕＯ和ＣｅＯ２发生烧结，晶粒变大     

Fabrication of p/n heterojunctions by electrochemical deposition of Cu2O onto TiO2 nanotubes

This work describes the TiO₂ nanotubes formation by anodic oxidation under different experimental conditions and the following attempts to optimize the electrochemical deposition of Cu₂O within the nanotubular structure. The as-formed Cu₂O/TiO₂ interface is a p/n junction that could be used in various light-assisted devices. The effect of the F^– concentration, the polarization duration and the post-thermal treatment on the TiO₂ nanotubes is recalled. Then the electrochemical deposition of cuprous oxide is investigated by cyclic voltammetry and the influence of the pH on the morphology and crystal structure is studied. Finally, potential pulses were applied to optimize the Cu₂O film morphology in order to improve the nanotubes covering.     

Neues zum chemischen Transport von CuO und Cu2O

New Results on the Chemical Transport of CuO and Cu₂O The preparation of CuO crystals by chemical transport reactions with HCl is already well known, a comparison with other transport agents based on the principal of thermodynamic equilibrium and also the rate of transport was missing up to now. We report about experiments with the transport agents HgCl₂, Cl₂, I₂, Nh₄Cl, or CuCl; the quantitative evaluation was made by means of the cooperative transport model on the basis of the free energy function. By this way it is possible to find favourable experimental conditions for the suitable transport agents at the outset. It turned out that HgCl₂ is an appropriate transport agent which can easily be weighed. Also I₂ is useful, whereas the effect fo transport with Cl₂ (1 atm/298 K), CuCl, or NH₄Cl is very small. We investigated the chemical transport of Cu₂o and the conditions for the change of its direction of transport.     

Controlled modification of multi-walled carbon nanotubes with CuO,Cu2O and Cu nanoparticles

Multi-walled carbon nanotubes (MWNTs) have been successfully modified with CuO, Cu₂O and Cu nanoparticles via a simple method, and the calcination temperature, the amount of NH₃·H₂O and soaking time play critical roles in controlling the final products. The modified MWNTs have been characterized by X-ray diffraction, infrared spectrum, scanning electron and transmission electron microscopies. Optical absorption of the obtained products has also been investigated, and the quantum confinement effect was illustrated in the absorption spectra.     

Comparative Study of CuO Species on CuO/Al2O3, CuO/CeO-Al2O3 andCuO/La2O-Al2O3 Catalysts for CO Oxidation

CuO/Al2O3, CuO/CeO2-Al2O3, and CuO/La2O3-Al2O3 (denoted as Cu/Al, Cu/CeAl, and Cu/LaAl) catalysts were prepared by an impregnation method. CuO species and CuO/Al2O3 thermal solid-solid interaction were characterized by in situ XRD, Raman spectroscopy and H2-TPR techniques. For the Cu/Al catalyst, a CuAl2O4 phase exists between the CuO and Al2O3 layer and the CuO phase exists on the surface in both highly dispersed and bulk forms. For the Cu/CeAl catalyst, there is highly dispersed and bulk CuO on the surface, but most of the CuO has transferred into the internal layer of CeO2 as bulk CuO and CuAl2O4. For the Cu/LaAl catalyst, only bulk CuO is present on the surface of the catalyst and no CuAl2O4 is formed. The catalytic activity order for CO oxidation is Cu/CeAl>Cu/Al>Cu/LaAl. The highly dispersed CuO on the catalyst surface may be the active phase for CO oxidation. The results show that the addition of CeO2 not only promotes both the transference of CuO and the formation of CuAl2O4 but also favors the CO oxidation due to the association of highly dispersed CuO with CeO2, while La2O3 hinders the transference of CuO and the formation of CuAl2O4.     

水热法合成纳米氧化铜粉体及其性能表征

氧化铜粉体广泛用于电极材料[1 ] 、玻璃、催化剂 (载体 )等领域。粒子的超细化 ,可以显著的改善氧化铜的应用性能。制备纳米氧化铜的方法有固相合成法[2 ] 、沉淀转化法[3] 和络合沉淀法[4] 。本文采用水热法一步合成了纳米氧化铜粉体 ,所得粉体粒度均匀 ,操作简便 ,易于工业化生产。1　实验部分1 1　样品制备将硝酸铜 (分析纯 ,北京化工二厂 )配成浓度为 1 .0ｍｏｌ·Ｌ- 1 的溶液 ,按物质的量比为 2∶1加入浓度为 1 .0ｍｏｌ·Ｌ- 1 的尿素 (分析纯 ,上海试剂一厂 )溶液 ,然后在 95℃～ 1 2 5℃下加热溶液进行反应。由于水溶液在 1 0 0…     

A controllable synthetic route to Cu,Cu2O,and CuO nanotubes and nanorods

Reducing Cu(OH)4(2-) with hydrazine hydrate and glucose in the presence of a structure-directing surfactant at room temperature gave Cu and Cu2O nanotubes/nanorods, respectively, whereas facile hydrothermal treatment of Cu(OH)4(2-) precursor resulted in CuO nanotubes/nanorods.     

Formation of uniform CuO nanorods by spontaneous aggregation: Selective synthesis of CuO, Cu2O, and Cu nanoparticles by a solid-liquid phase arc discharge process

Uniform and monodisperse CuO nanorods have been synthesized by directional aggregation and crystallization of tiny CuO nanoparticles generated from a solid-liquid arc discharge process under ambient conditions in the absence of any surfactants. Uniform CuO nanorods with sharp ends are formed from tiny nanoparticles via a process that involves the rapid oxidation of Cu nanoclusters, the spontaneous aggregation of CuO nanoparticles, and the Ostawald ripening process. The spontaneous aggregation and oriented attachment of tiny CuO nanoparticles contributed obviously to the formation of these kinds of nanostructures. By choice of suitable reducing agent to prevent the oxidation of Cu nanoclusters, Cu and Cu2O nanoparticles can be selectively synthesized.