CuCl Nanoparticles Research Articles

Cu-MOF derived two-dimensional copper-carbon nanosheets for efficient nitrate reduction

In recent years, the strategy of reducing ammonia (NH3) from nitrate-related sources such as industrial wastewater driven by clean energy sources has garnered significant attention. Previous studies have shown that Cu-based species can effectively catalyze nitrate reduction reaction (NO3RR), but the reaction intermediates tend to aggregate on the surface of catalysts, resulting in low Faraday efficiency. In this study, two-dimensional porous carbon nanosheets were successfully prepared through direct pyrolysis of a mixture of ZnCu-BTC crystal and FeCl3 salt. Interestingly, cube-shaped CuCl nanoparticles were easily precipitated from the MOF-derived carbon surface during acid etching process. The resulting CuCl-CNS exhibited good NO3RR performance, achieving an NH3 yield of 96.9 % and 292.5 µmol h−1 cm−2 at −0.60 V versus reversible hydrogen electrode. Moreover, the assembled zinc-nitrate battery revealed a peak power density of 4.73 mW cm−2 and long-term cycle stability. This work provides valuable insights into the development of MOF-derived Cu-based nanocomposites for effective nitrate reduction.

Impact of nanoscale Cu (I) precursors prepared by solution process on large-area CdTe solar cells

In recent years, the study of Cu (Ӏ) precursors in high-performance CdTe thin-film solar cell devices has received increasing attention. However, few studies have been reported on nanoscale Cu (I) precursors in large-area CdTe devices (≥1 cm2). Here, three different Cu (Ӏ) nano precursors have been rapidly prepared by solution method (CuCl ethanol solution, CuI acetonitrile solution, and CuSCN aqueous ammonia solution) and their effects on the performance of commercial large-area CdTe thin-film solar cells have been investigated. The results show that the distribution amount and uniformity of the nano precursor particles on the CdTe back surface have a large impact on the device performance. The CuCl nanoparticles are more uniformly distributed and the device performance is more excellent. CuI nanoparticles easily formed clusters at grain boundaries. Denser distribution of CuSCN nanoparticles. The thermal diffusion conditions (temperature, time and precursor concentration) have a significant effect on the device performance, but the most reasonable thermal diffusion conditions tend to be the same for all devices. This suggests that the thermal diffusion conditions are determined by the nature of the CdTe absorber layer itself and are not interfered by different nano precursors.

Enhancing electrochemical properties of commercial lithium titanate using cuprous chloride nanoparticle-modified copper foil current collectors

For the first time, CuCl nanoparticles were fabricated at ambient temperature onto the surface of a copper (Cu) foil current collector through using an immersing approach, in which the immersing solution only contained 0.6 M CuSO4 and a very small amount of hexadecyl trimethyl ammonium chloride (HTAC). For simplicity, all as-prepared CuCl nanoparticles modified copper foils were labeled as CuCl/Cu. The specimens of CuCl/Cu prepared in the presence of 4 mM, 8 mM and 12 mM HTAC were designated as specimen a, b and c, respectively. The lithium titanate (Li4Ti5O12, LTO) electrodes assembled using the as-prepared CuCl/Cu exhibited an outstanding electrochemical performance as compared to the conventional LTO electrode manufactured using the commercial bare copper foil. Such as, the initial discharge capacity (DC) value of the LTO electrode assembled using specimen b at 0.2 C was measured to be 216 mAh g−1, which was about 1.3 times that of the conventional LTO electrode (165 mAh g−1). More importantly, at 10 C after 100 cycles, the DC value of the LTO electrode assembled using specimen b was retained to be as high as 143 mAh g−1, being about 3.1 times higher than that of the conventional LTO electrode (46 mAh g−1). A room temperature immersing approach for preparing CuCl nanoparticles and a novel method to significantly improve the electrochemical behavior of the conventional LTO electrode are developed in this work, which is very meaningful not only to the development of CuCl related material science but also to the further progress of LTO based lithium ion batteries (LIBs).

Construction of CuII Defects on CuCl Nanoparticles in Metal-Organic Frameworks toward Composite Catalysts with Superior Activity.

Metal-organic frameworks (MOFs) represent an ideal platform for the construction of highly active composite catalysts. However, loading metastable and/or multicomponent metal compounds into MOFs remains a synthetic bottleneck due to the great challenge of keeping the guest and matrix intact during the preparation of a composite. In this work, we develop a new impregnation reduction surface modification (IRSM) strategy to give a new composite catalyst CuCl@MIL-101(Cr), which is successfully postmodified by in situ construction of CuII defects on the surface of loaded CuCl inside MOF pores, leading to the new composite material CuII/CuI@MIL-101(Cr). The new dual-component composite catalyst exhibits a hierarchical structure and superior catalytic activity in C-C homocoupling of arylboronic acids under green conditions. This study presents a facile strategy for improving the catalytic activity by constructing defects on the surface of MOF-based catalysts as well as for forming multiple-component composite materials.

Nucleation of CuCl in Glass at the Sample Heating Stage

The peculiarities of the nucleation of CuCl nanoparticles at the heating stage in sodium-aluminum-borosilicate glass are studied by the method of exciton-thermal analysis. It is found that the concentration of CuCl particles in this process reaches its maximum. The concentration of CuCl particles increases as the heating time increases, while the average radius decreases. The numerical simulation shows that heating leads to the development of the maximum number of new phase nuclei due to the rapid growth of the critical radius. From a certain moment of heating, the dissolution of previously formed nuclei is observed. The CuCl phase concentration and the average radius of the particles’ radial distribution under heating for more than 5 min tend to the equilibrium value for the corresponding nucleation temperature.

Nonisothermal nucleation in a solid solution of CuCl in glass: Concentration effect upon heating of the solid solution

The influence of the heating rate of a solid solution of CuCl in glass on the size distribution of the produced CuCl nanoparticles is studied. The distribution curves of CuCl nanocrystals are determined by the method of exciton-thermal analysis. It is established that the concentration of CuCl nanoparticles increases by ten times upon slowing the sample heating process from 2 to 60 min, while the mean radius of particles decreases almost twice. The concentration of CuCl nanoparticles passes through a maximum in the process of heating the sample. The numerical simulation of the nucleation upon slow heating of a solid solution showed that the formation of the concentration maximum of the new phase clusters is determined by a rapid increase in the critical radius owing to an increase in temperature and decrease in the solution supersaturation. As a result, the formation of new phase nuclei ceases at a certain temperature, and a part of the previously formed clusters dissolves.

The details of the formation of CuCl nanoparticles in photochromic glass

The details of the formation of CuCl nanoparticles in the sodium alumina-borosilicate glass for different methods of thermal treatment of the samples are studied by exciton thermal analysis. It is revealed that the formation of the CuCl phase in glass depends on the heating rate of the samples to the predetermined temperature of isothermal annealing. The concentration of the nucleating centers of the CuCl phase reaches its peak value at 600°C during slow (60 min) heating up to 650°C, due to the fast increase of the critical size of particles of the phase as a result of the fast temperature increase and the rapid decrease of supersaturation in glass. As a result, the formation of new CuCl nucleation centers terminates above 600°C, and part of the centers formed earlier whose size is less than critical dissolve, which results in the monotonic decrease of the CuCl particle concentration.

Exciton-thermal analysis of nonisothermal nucleation in solid solution of CuCl in glass

The work presents results of investigation of nucleation of CuCl nanocrystals in glass by method of exiton-thermal analysis (ETA) which is based on measuring the optical absorbance of CuCl phase in sample under heating up to the melting temperature of CuCl nanocrystals. The melting temperature of nanoparticle depends on its radius. Therefore analysis of curve of melting CuCl phase allows to determine distribution curve of nanoparticles on their radii. By the method of ETA the features of variation of CuCl nanoparticles distributions in glass when changing regime of sample annealing (nonisothermal nucleation) were studied. For example, by reducing the heating rate of the sample the concentration of particles of CuCl phase increases considerably while reducing average radius.

Oxidative esterification of methylarenes and 1,3‐dicarbonyls catalysed by copper chloride immobilized on magnetic nanoparticles

Superparamagnetic CuCl nanoparticles were prepared and identified as an effective heterogeneous catalyst for the tandem transformation of methylarenes and 1,3‐dicarbonyl compounds into the corresponding enole esters by the use of tert‐butyl hydroperoxide as an external oxidant. The catalyst can be removed from the reaction medium simply by use of an external magnet. As a consequence, various derivatives of enol esters were synthesized in moderate to good yields.

Binder-free integration of insoluble cubic CuCl nanoparticles with a homologous Cu substrate for lithium ion batteries

Binder-free integration of a novel insoluble cubic cuprous chloride (CuCl) nanoparticle anode material with homologous Cu foil was designed and achieved via facile in situ electrochemical self-assembly for the first time.

Nonisothermal nucleation in the CuCl solid solution in glass: Nucleation under continuous cooling of the solid solution

The processes of nonisothermal nucleation in the CuCl solid solution in glass under continuous cooling from 700 to 500°C have been investigated. It has been shown that, in the studied cooling modes, regardless of the cooling rate, two distributions of CuCl nanoparticles with radii in the ranges of 8–20 and 2.5–3.5 nm in the absence of particles with intermediate radii are formed. The simulation of the nucleation under continuous cooling of the solid solution has revealed some features in the kinetics of the formation of two distributions of nanoparticles that differ significantly in size. It has been found that, under specific conditions, there can arise one wide distribution (strongly overlapping distributions). The role of a change in the critical radius during the nonisothermal nucleation (cooling of the solid solution) in the formation of a binary distribution has been demonstrated.

Influence of picosecond multiple/single line ablation on copper nanoparticles fabricated for surface enhanced Raman spectroscopy and photonics applications

A comprehensive study comprising fabrication of copper nanoparticles (NPs) using picosecond (ps) multiple/single line ablation in various solvents such as acetone, dichloromethane (DCM), acetonitrile (ACN) and chloroform followed by optical, nonlinear optical (NLO), and surface enhanced Raman spectroscopy (SERS) characterization was performed. The influence of surrounding liquid media and the writing conditions resulted in fabrication of Cu NPs in acetone, CuCl NPs in DCM, CuO NPs in ACN and CuCl2 NPs in chloroform. Prepared colloids were characterized through transmission electron microscopy, energy dispersive x-ray spectra, selected area electron diffraction and UV-visible absorption spectra. A detailed investigation of the surface enhanced Raman scattering (SERS) activity and the ps NLO properties of the colloids prepared through multiple/single line ablation techniques revealed that the best performance was achieved by Cu NPs for SERS applications and CuCl2 NPs for NLO applications.

Nonisothermal nucleation in the CuCl solid solution in glass: Formation of two distributions of nanoparticles of a new phase in the solid solution with a negative jump of the nucleation temperature

The processes of nonisothermal nucleation in the CuCl solid solution in glass with a negative jump of the nucleation temperature have been investigated using optical spectroscopy and exciton-thermal analysis. Two distributions of CuCl nanoparticles differing in the average radii R (2.3 and 14.0 nm) have been obtained for the temperature drop from T 1 = 700°C to T 2 = 500°C. The formation of two distributions of CuCl particles has been numerically simulated and the agreement between the experimental and calculated radius distributions of CuCl particles has been obtained.

Synthesis and Characterization of CuCl Nanoparticles in Deep Eutectic Solvents

In the present work, CuCl nanoparticles were fabricated in deep eutectic solvents (DES) which is a new kind of ionic liquid with special properties. The as-prepared samples were characterized by x-ray diffraction, scanning electron microscopy, and transmission electron microscopy. The effect of polyvinylpyrrolidone (PVP), the molar ratio of ascorbic acid to copper chloride and the mixing method were investigated. The optimized reaction conditions were as follows: reaction time is 1 h, reaction temperature is 25°C in the presence of PVP in deep DES. Under the optimum conditions, CuCl nanoparticles with the average size about 50 nm could be successfully prepared in DES.

Formation of two distributions of nanoparticles of a new phase in a solid solution

Processes of the formation of the double distribution of CuCl nanoparticles in glass in two-stage annealing have been analyzed. The distribution of CuCl nanoparticles with the average radius R 1 = 14 and 18 nm appears in 20 and 40 min at temperature T 1 = 700°C in samples 1 and 2, respectively. By this time, the formation of new clusters ends, and only the growth of previously formed clusters occurs (the second stage of nucleation). Then, the formation of the CuCl phase continues at T 2 = 500°C. A decrease in the temperature is accompanied by a decrease in the critical radius of particles of a new phase. For this reason, the formation and growth of new CuCl nuclei begin again and the second distribution with a mean radius of 1 nm or larger is formed. As a result, double distributions of CuCl nanoparticles with significantly different mean radii are formed in samples 1 and 2. The concentration and mean radius of CuCl particles in distributions have been determined from the optical absorption spectra of CuCl nanocrystals at 80 K in the wavelength range of 300–500 nm.

Nucleation kinetics in a CuCl solid solution in glass: Calculation and comparison with experiment

The kinetics of formation of CuCl nanoparticles in a glass has been studied. The experimental results obtained have been compared with the results of calculations. A method has been developed for calculating the nucleation kinetics, which decreases the time of calculations by a factor of several tens. This has been achieved using the joint kinetic equation for distributions of clusters over the number of particles and over the radius. The distributions over the number of particles and over the radius have been used for small and large clusters, respectively. The concentration of molecules near the surface of clusters has been determined from the asymptotic solution of the diffusion equation. For subcritical clusters, the concentration of molecules near the cluster surface has been taken to be equal to the average concentration in the solid solution. This method has been used to calculate the nucleation kinetics of CuCl nanoparticles in a glass. The results obtained from the calculation of the time dependences of the increase in the concentration and average radius of clusters agree well with experiment.

Size distribution of CuCl nanoparticles in glass in various stages of nucleation

Variations in the size distribution of CuCl particles in the glass formed at different temperatures are studied via the temperature-dependent exciton spectra (the exciton-thermal analysis). The kinetics of melting of CuCl nanocrystals is measured via changes in the strength of exciton absorption during linear heating of the sample. Then, using the known dependence of the melting temperature of CuCl nanoparticles on their size, the size distribution of the CuCl nanocrystals is found. During the first, second, and early third stages of nucleation, the width δ of the size distribution grows with an increase in the mean radius of the nanoparticles Rm. During the first nucleation stage, when Rm = 1.2 nm, which is just above the critical radius, the ratio δ/Rm is about 0.2. While the mean radius of the distribution increases to 8 nm, the ratio δ/Rm varies only slightly in the range 0.20−0.35. A further increase in the mean radius of the distribution to 16 nm is accompanied by a twofold increase in the δ/Rm ratio. The shape of the distribution is close to Gaussian both at the initial and later stages of the growth of CuCl particles in glass.

Transformation of the short-range order upon melting of CuHal nanocrystals in glasses

The reduced density of states at the edge of interband transitions in CuCl and CuBr nanocrystals is described by a step at T → 0. As the temperature increases, the step is smeared toward the band gap and the long-wavelength absorption tail agrees with the Urbach rule. A change in the phase state of CuCl or CuBr nanoparticles (the crystal-melt transition) is accompanied by an insignificant change in the band gap, and the long-wavelength absorption tail for the interband transitions considerably extends deeper into the band gap as compared to that for crystals at the same temperature. The change observed in the band gap upon melting is explained by the transformation of short-range order in CuCl and CuBr melts. An increase in thermal smearing of the long-wavelength absorption tail for nanomelts is associated with the severalfold increase in the amplitude of thermal fluctuations of the band gap, possibly, due to the disappearance of the long-range order in the melts. A lower melting temperature of large (>30 nm) CuCl and CuBr particles as compared to the melting temperature of bulk samples indicates the presence of the second component NaCl or NaBr. Consequently, the CuCl-NaCl and CuBr-NaBr eutectic nanosystems undergo melting and crystallization. A small shift in the band gap observed in this case upon melting confirms the conclusion drawn by Zalkin that eutectic melts have a microheterogeneous structure.

Spatial properties and coherence of the high density phase in the microcavity optical parametric oscillator

AbstractThe special issue entitled “Frontiers in Semiconductor Nanoscience” with a total of more than forty contributions from leading scientists in semiconductor and nanostructure physics has been prepared to honor Gerhard Abstreiter, Technische Universität München. The present Part B contains Feature Articles and Original Papers in the areas of quantum transport, optical properties and coherent phenomena. Part A of the special issue on nano‐biological systems, novel materials and nanostructures is published in phys. stat. sol. (a) 203, No. 14 (2006).The cover picture has been taken from the Feature Article [1] by Maurice Skolnick et al. It illustrates a calculation of the signal distribution and photonic potential (white contours) in a microcavity optical parametric oscillator with evidence for strong localisation in the potential minima.This issue also contains articles presented at the 7th International Conference on Excitonic Processes in Condensed Matter held in Winston‐Salem, USA, 26–30 June 2006. They include the Editor's Choice “Optical manipulation of CuCl nanoparticles under an excitonic resonance condition in superfluid helium” by K. Inaba et al. The first author received one of the two EXCON Prizes sponsored by Wiley‐VCH. More contributions from EXCON'06 can be found in phys. stat. sol. (c) 3, No. 10 (2006). (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Optical manipulation of CuCl nanoparticles under an excitonic resonance condition in superfluid helium

AbstractIn order to prepare the optimal condition for the resonant optical manipulation, a lot of CuCl particles with a broad size‐distribution ranging from 10 nm to 10 μm have been directly fabricated from a bulk sample by laser ablation in superfluid helium. We irradiated these particles with the laser light covering the excitonic resonance levels of particles smaller than 100 nm in order to transport them onto a target silicon substrate by using resonant radiation force. As a result, we have observed that many particles of from 10 to 50 nm diameters adhere to the substrate. This means that these nanoparticles are transported by the resonant radiation force much stronger than the gravitational force. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)