Incorporation Of Cu Research Articles

PdCu Bimetallene for Enhanced Oxygen Reduction Electrocatalysis.

Engineering two-dimensional (2D) metallic nanomaterials has attracted numerous research interests for oxygen reduction reaction (ORR) due to their highly exposed unsaturated metal atoms and excellent physicochemical properties. Herein, we report a CO-confined growth strategy for the synthesis of 2D PdCu bimetallene with several atomic layers for ORR. The incorporation of Cu into Pd metallene can generate strain effect and change the electronic structure, weakening the interaction between Pd and CO and suppressing the adsorption of CO. Therefore, the synthesized PdCu bimetallene exhibits remarkable catalytic performance for alkaline ORR, with mass and specific activities of 0.82 A mgPd-1 and 1.01 mA cm-2, which are 5.1 and 3.7 times those for Pt/C, respectively. Meanwhile, the PdCu bimetallene shows no decrease in ORR activity after 5000 cycles. This work highlights the design of ultrathin bimetallic 2D nanomaterials for efficient ORR electrocatalysis.

Colorimetric and fluorescence detection of circulating tumor cells based on a bimetallic-organic framework

An ultrasensitive colorimetric and fluorescence dual-readout method was developed for detecting circulating tumor cells (CTCs) using a CuFe-based bimetallic-organic framework (CuFe-NH2-MIL-101, bi-MOF). Incorporation of Cu into an Fe-based metal–organic framework (MOF) led to improved fluorescence compared with that of monometallic analogues. The synthesized bi-MOF exhibited improved fluorescence. The synthesized bi-MOF also exhibited enzyme-mimetic activity. The CTCs were bound by biotinylated antibodies and then selected and enriched by streptavidin-coated magnetic beads. With peroxidase-mimicking activity and enhanced fluorescence, the CuFe bi-MOF functioned as a signal-amplifying nanoprobe for colorimetric and fluorescence detection. The absorbance increased with increasing concentration of tumor cells, whereas the fluorescence intensity gradually decreased. Under optimized conditions, the sensor exhibited a detection range of 102–107 cells mL−1. The detection limit of this cytosensor could reach 7 cells mL−1. Moreover, this sensor showed reliable applicability in real serum samples. Overall, this dual-readout strategy holds potential for the detection of CTCs in clinical diagnostics.

Bottom-Up Synthesis of Metalated Carbyne Ribbons via Elimination Reactions

Elimination reactions are one of the most important reactions in organic synthesis, especially in the formation of alkenes and alkynes. Herein, based on scanning tunneling microscopy, we report the bottom-up synthesis of one-dimensional carbyne-like nanostructures, metalated carbyne ribbons with the incorporation of Cu or Ag atoms, through α- and β-elimination reactions of tetrabromomethane and hexabromoethane on surfaces. Density functional theory calculations demonstrate a width-dependent band gap modulation within these ribbon structures, which is affected by interchain interactions. Moreover, mechanistic insights into the on-surface elimination reactions have also been provided in this study.

A Cu+ /Thiourea Dendrimer Achieves Excellent Cytosolic Protein Delivery via Enhanced Cell Uptake and Endosome Escape.

Intracellular protein delivery has attracted considerable attention in the development of protein-based therapeutics, however, the design of highly efficient materials for robust delivery of native proteins remains challenging. This study proposes a Cu+ -based coordination polymer for cytosolic protein delivery with high efficacy and robustness. The phenylthiourea grafted dendrimer is coordinated with cuprous ions to prepare the polymeric carrier, which efficiently bind cargo proteins via a combination of coordination, ionic and hydrophobic interactions. The incorporation of Cu+ ions in the polymer greatly improves its cellular uptake and endosomal escape. The cuprous-based coordination polymer successfully delivered a variety of structurally diverse proteins into various cell lines with reserved bioactivities. This study provides a new type of coordination polymers for cytosolic delivery of biomacromolecules.

Ultrathin Two-Dimensional BiOCl-Bi2 S3 -Cu2 S Ternary Heterostructures with Enhanced LSPR effect for NIR Photonic Bacterial Disinfection.

Photonic disinfection, particularly near-infrared (NIR) light triggered antibacterial, has emerged as a highly promising solution for combating pathogenic microbes due to its spatiotemporal operability, safety, and low cost of apparatus. However, it remains challenging to construct NIR-responsive antibacterial agents with high light-converting efficacy and elucidate synergistic mechanisms. In this work, ultrathin two-dimensional (2D) BiOCl-Bi2 S3 -Cu2 S ternary heterostructures that can efficiently kill drug-resistant bacteria were synthesized by doping 0D Bi2 S3 and Cu2 S nanoparticles in the 2D BiOCl nanosheets via a facile one-pot hydrothermal method. Notably, the incorporation of Cu2 S nanoparticles bestows strong NIR light-harvesting capability to the composite nanosheets due to their localized surface plasmon resonance (LSPR). Upon NIR light illumination, the BiOCl-Bi2 S3 -Cu2 S nanosheets can achieve enhanced photonic hyperthermia and reaction oxygen species (ROS) generation, serving as single light-activated bi-functional photothermal/photodynamic therapeutics. High-speed hot electrons and large local electronic fields caused by LSPR might play an important role in thermal vibrations and effective carrier separations, respectively. Benefiting from the unique ternary heterostructures, both the photothermal conversion and ROS generation efficacy of BiOCl-Bi2 S3 -Cu2 S nanosheets are significantly improved compared to the binary BiOCl-Cu2 S or BiOCl-Bi2 S3 nanosheets. Accordingly, the ternary composite nanosheets can effectively kill bacteria via the NIR-driven photonic disinfection mechanism. This work presents a new type of 2D composite nanosheets with ternary heterostructures for NIR photonic disinfection.

Visible active narrow/narrow band gap CuO/Cu2SnS3 nanoheterostructures as efficient nanophotocatalysts.

Binary metal oxide/ternary metal sulphide based nanoheterostructures, such as CuO/Cu2SnS3, were prepared via a modified hydrothermal route. The prepared nanoheterostructures were characterized using scanning electron microscopy, x-ray powder diffractometer, XPS, ultraviolet-visible spectroscopy, isoelectric point, and Brunauer-Emmett-Teller techniques. The XPS results revealed the successful incorporation of Cu+/Cu2+ with different ratios. The prepared heterostructures were tested as solar active photocatalysts for Methylene Blue (MB) photodegradation. The CuO/Cu2SnS3 (20% Cu2SnS3/80% CuO) photocatalytic results exhibited a high photodegradation efficiency (90%) after 60min. In addition, the photonic efficiency values (ζ) were calculated to be 15.9%, 44%, and 61.4% for CuO, Cu2SnS3, and CuO/Cu2SnS3 nanoheterostructures, respectively. In addition, the reactive oxidative species were detected by the trapping experiments to get a clear insight about the photocatalytic reactivity factors. Total organic carbon (TOC) was conducted to confirm the safe photodegradation of MB dye without the formation of colorless hazardous (95.5% TOC removal). Based on the electronic band structure, the mechanism of photodegradation was investigated. The currently investigated heterostructure system is narrow/narrow bandgap, which fulfills the two contradictory conditions in terms of high solar photocatalytic activity and overcomes the rapid recombination process.

Synthesis of Fe-TiO2 and Cu-TiO2 Based Materials by Olive Leaves Biotemplating—Application to Hydrogen Production from Glycerol Photoreforming

Hydrogen production is mainly based on the use of fossil fuels, but currently, many alternative routes are being developed, among which the photo-reforming of oxygenated organic compounds stands out. Recently, several studies have been carried out in order to develop new techniques to create bio-inspired TiO2 structures. One of these is 'biotemplating', a process that replicates a biological system in an inorganic TiO2-based structure. In this study, olive by-products-olive leaves-are valorized as a biotemplate for the synthesis of new Fe-TiO2- and Cu-TiO2-based photocatalysts with the aim of improving the replication of the leaf structure and enhancing hydrogen photoproduction. In conclusion, the incorporation of iron and copper decreases the band gap and increases the energetic disorder at the band edges. Moreover, it is verified by SEM and TEM that the metals are not found forming particles but are introduced into the formed TiO2 structure. The accuracy of the internal and external structure replication is improved with the incorporation of Fe in the synthesis, while the incorporation of Cu substantially improves the production of hydrogen, which is multiplied 14 times under UV light and 6 times under sunlight, as compared to a pure TiO2 structure.

Engineering of efficient visible light photocatalysts: Ti1–x+yCuxLayO2 (x = 0.03; y = 0, 0.005, 0.01) compositions

In dye-photocatalysis, widening the wavelengths absorption range of catalysts as well as aborting the recombination of the photoexcited charge carriers (electrons–holes pairs) are of paramount significance. In the current study, we report the photocatalytic characteristics of four compositions composed of TiO2, Ti0.97Cu0.03O2, Ti0.965Cu0.03La0.005O2 and Ti0.96Cu0.03La0.01O2 powders for two harmful dyes (Congo red and methylene blue). The X-ray diffraction technique verified the configuration of mixed anatase and rutile phases in pure TiO2 and Ti0.97Cu0.03O2 powders while Ti0.965Cu0.03La0.005O2 and Ti0.96Cu0.03La0.01O2 powders possess anatase phase only. The changes of the band gap structure and dimensions of the unit cell volume of TiO2 confirm the substitution of Ti4+ sites by Cu2+ and La3+ ions. Remarkable widening of wavelengths absorption with formation of long absorption tails were found in TiO2 (3.13 eV) through insertion of La3+ plus Cu2+ ions. Ti0.965Cu0.03La0.005O2 and Ti0.96Cu0.03La0.01O2 samples exhibit a visible light band gap of 2.3 and 2.7 eV, respectively. Based on SEM images, incorporation of Cu2+ and La3+ ions influences the surface morphology of TiO2. The resulting Ti0.97Cu0.03O2, Ti0.965Cu0.03La0.005O2 and Ti0.96Cu0.03La0.01O2 powders present enhanced photocatalytic activity towards Congo red dye degradation compared to pure one under natural solar spectrum. The best Ti0.96Cu0.03La0.01O2 catalyst exhibits superior photocatalytic activity of 96% for 10 ppm CR dye in 20 min as well as above average photocatalytic efficiency of 63% for 30 ppm CR dye in 120 min. As well, it showed acceptable photodegradation activity of 52% for 30 ppm MB solution in 140 min of sunlight irradiation. The heightened photodegradation efficiency of Ti0.96Cu0.03La0.01O2 catalyst can be clarified in terms of higher charge carriers’ separation (Cu2+ + e– → Cu+, La3+ + e– → La2+), oxygen vacancies, full anatase phase structure as well as the wide range of visible light absorption.

Strain-Driven Solid-Solid Crystal Conversion in Chiral Hybrid Pseudo-Perovskites with Paramagnetic-to-Ferromagnetic Transition.

Hybrid organic-inorganic perovskites (HOIPs) are promising stimuli-responsive materials (SPMs) owing to their molecular softness and tailorable structural dimensionality. The design of mechanically responsive HOIPs requires an in-depth understanding of how lattice strain induces intermolecular rearrangement that impacts physical properties. While chirality transfer from an organic cation to an inorganic lattice is known to influence chiral-optical properties, its effect on strain-induced phase conversion has not been explored. As opposed to achiral or racemic organic cations, chiral organic cations can potentially afford a new dimension in strain-responsive structural change. Herein, we demonstrate that mechanical strain induces a solid phase crystal conversion in chiral halide pseudo-perovskite single crystals (R/S)-(FE)2CuCl4 (FE = (4-Fluorophenyl)ethylamine) from a 0D isolated CuCl4 tetrahedral to 1D corner-sharing CuFCl5 octahedral framework via the incorporation of Cu···F interaction and N-H···F hydrogen bonding. This strain-induced crystal-to-crystal conversion involves the connection of neighboring 0D CuCl4 tetrahedra via Cu2+-Cl--Cu2+ linkages as well as the incorporation of a F-terminated organic cation as one of the X atoms in BX6 octahedra, leading to a reduced band gap and paramagnetic-to-ferromagnetic conversion. Control experiments using nonchiral or racemic perovskite analogs show the absence of such solid phase conversion. To demonstrate pressure-sensitive properties, the 0D phase is dispersed in water-soluble poly(vinyl alcohol) (PVA) polymer, which can be applied to a large-scale pressure-induced array display on fibrous Spandex substrates via a screen-printing method.

Architecture of copper sulfide heterojunction and sodalite zeolite for synergistically improving catalytic effectiveness toward methanol oxidation

CuxS derivatives perform high activity in MOR (methanol oxidation reaction) through the co-operation of Cu and S. In order to further improve their performance, the composition and structure are regulated through the co-growth process of copper sulfide heterojunction and SOD (sodalite code) zeolite framework. Under the hydrothermal condition, the introduced Cu0 and Cu+ ions are clustered on the zeolitic surface and inner cages. The S2- anions are selectively located at the zeolite cage to balance the framework charge arisen from the incorporation of Cu+. In the electrochemical process, the optimized Cu2S/SOD zeolite electrode reveals an extra high efficiency of 8847 A g−1 at an extra low overpotential of 0.374 V with an excellent resistance to catalyst poisoning in high concentration of methanol. This work opens up a new method for the design and industrial application of non-precious metal electrocatalysts with high energy density based on porous zeolite materials.

Incorporation of Cu into Goethite Stimulates Oxygen Activation by Surface-Bound Fe(II) for Enhanced As(III) Oxidative Transformation.

The dark production of reactive oxygen species (ROS) coupled to biogeochemical cycling of iron (Fe) plays a pivotal role in controlling arsenic transformation and detoxification. However, the effect of secondary atom incorporation into Fe(III) oxyhydroxides on this process is poorly understood. Here, we show that the presence of oxygen vacancy (OV) as a result of Cu incorporation in goethite substantially enhances the As(III) oxidation by Fe(II) under oxic conditions. Electrochemical and density functional theory (DFT) evidence reveals that the electron transfer (ET) rate constant is enhanced from 0.023 to 0.197 s-1, improving the electron efficiency of the surface-bound Fe(II) on OV defective surfaces. The cascade charge transfer from the surface-bound Fe(II) to O2 mediated by Fe(III) oxyhydroxides leads to the O-O bond of O2 stretching to 1.46-1.48 Å equivalent to that of superoxide (•O2-), and •O2- is the predominant ROS responsible for As(III) oxidation. Our findings highlight the significant role of atom incorporation in changing the ET process on Fe(III) oxyhydroxides for ROS production. Thus, such an effect must be considered when evaluating Fe mineral reactivity toward changing their surface chemistry, such as those noted here for Cu incorporation, which likely determines the fates of arsenic and other redox sensitive pollutants in the environments with oscillating redox conditions.

Unique Microstructures and High Thermoelectric Performance in n–type Bi2Te2.7Se0.3 by the Dual Incorporation of Cu and Y

n-type thermoelectric systems operating near ambient temperature have been significantly understudied. n-type Bi2Te3-based materials have suffered from lack of efficient performance-enhancing strategies and compositional diversity mainly due to the difficulty in efficient doping and alloying to their structure. Herein, we report new n-type thermoelectric system Bi2-xYxTe2.7Se0.3 (x = 0 – 0.020) and optimized Cu0.01Bi1.985Y0.015Te2.7Se0.3 involving unique yttrium selenide-based microstructures. The incorporated Y and Cu atoms serve multiple favorable roles in improving thermoelectric performance of the title samples. A majority of the introduced Y forms either semiconducting Y2Se3 or metallic Y5-δSe7 depending on its chemical pressure, significantly affecting both thermal and charge transport properties. Changing the Y concentration in the nominal composition dynamically changes the composition of the surrounding matrix, microstructures, and their interfaces. The generation of microstructures and compositional variance driven by the Y and Cu incorporation can be understood and controllable in light of hard-soft acid-base principle and structural chemistry of the constituent elements. Cu atoms are more abundant in the interface than the other areas, and richer inside the microscale precipitate than the surrounding matrix, thereby creating large mass and compositional fluctuation. The Raman spectra verify that the incorporated Y and Cu atoms contribute to scattering and softening phonon modes effectively. All these jointly depress the lattice thermal conductivity of the optimized phase Cu0.01Bi1.985Y0.015Te2.7Se0.3 to ∼0.51 W m-1 K-1 at 300 K. The dual incorporation of Cu and Y atoms induces heavier density of states effective mass, thereby improving a magnitude of Seebeck coefficients. Accordingly, power factor increases especially near room temperature, giving ∼39.1 μW cm-1 K-2 at 300 K. Consequently, the Cu0.01Bi1.985Y0.015Te2.7Se0.3 sample achieves a high thermoelectric figure of merit, ZT, of ∼1.20 at 347 K and an average ZT of ∼1.16 from 300 to 423 K. Its ZT of ∼1.09 at 300 K is comparable to the state-of-the-art n-type polycrystalline Bi2Te3 systems.

Improving the Heat Transfer of Phase Change Composites for Thermal Energy Storage by Adding Copper: Preparation and Thermal Properties

Phase change materials (PCMs), as an effective thermal energy storage technology, provide a viable approach to harness solar heat, a green energy source, and optimize energy consumption in buildings. However, the obstacle preventing widespread practical use of PCM is its poor performance in terms of heat transfer and shape stabilization. This article focuses on the application of the shape stabilization method. To improve the thermal conductivity of organic PCMs (hexadecane), copper microparticles are added to form phase change composites (PCC). This process allows an enhanced PCM (75 wt%) that distributes effective thermal storage capabilities while maintaining low cost. SEM, FTIR, ATG, infrared thermography (IRT), and DSC were used to characterize the composites’ micromorphology, chemical composition, thermal degradation stability, and thermal energy storage capabilities. DSC results showed that a proportion of 75 wt% phase change material with 15 wt% Cu had excellent thermal stability and high energy storage density per unit mass. In light of its high latent heat storage capacity of 201.32 J/g as well as its ability to prevent Hexadecane exudation, PCC ensures higher thermal conductivity and shape stability during phase transition than ordinary PCM. The incorporation of Cu to paraffin causes delay in PCM phase transformation, leading it to respond to rapid charging and discharging rates and, consequentially, to challenges in temperature control, as shown by IRT. The new PCCs had favorable thermal stability below 100 °C, which was advantageous for practical application for thermal energy storage and management, and notably for solar thermal energy storage.

Photoelectrocatalytic oxidation of ethylene glycol on trimetallic PdAgCu nanospheres enhanced by surface plasmon resonance

The notable surface plasmon resonance (SPR) effect of some metals has been applied to improve the efficiency of alcohol oxidation reactions, whereas the comprehensive investigation of Cu-assisted photoelectrocatalysis remains challenging. We herein successfully prepared trimetallic PdAgCu nanospheres (NSs) with abundant surface bulges for the advanced ethylene glycol oxidation reaction (EGOR) and compared them with bimetallic PdAg NSs to investigate the performance enhancement mechanism. Impressively, the as-optimized PdAgCu NSs exhibited superb mass activity and electrochemical stability. Moreover, under visible light illumination, the mass activity of PdAgCu NSs increased to 1.62 times compared to that in the dark, and in contrast, the mass activity of PdAg NSs only increased to 1.48 times that in the dark. A mechanistic study indicated that the incorporation of Cu not only strengthens the whole SPR effect of PdAgCu NSs but also further modifies the electronic structure of Pd. This work highlighted that the incorporation of Cu into PdAg NSs further enhanced the photoelectrocatalytic performance and increased noble metal atom utilization, which may provide guidance to fabricate novel and promising nanocatalysts in the field of photoelectrocatalysis.

2D/2D Transition‐Metal‐Sulfide Self‐Assembly Enables a Huge Tolerance to High Concentration Cr(VI) and a Prominent Photocatalytic Reduction Performance

AbstractTwo‐dimensional (2D) transition‐metal‐sulfides always suffer from poor optical absorption ability, serious photogenerated carrier recombination, and lack of tolerance to high concentration Cr(VI), which limit their wide applications. Herein, 2D MoS2 nanosheets are in situ grown on 2D 5 % Cu‐doped ZnIn2S4 nanosheets to fabricate self‐assembly via a two‐step solvothermal method. The incorporation of Cu broadens the optical response range of self‐assembly and introduces an acceptor trap level that changes the valence band allocation of ZnIn2S4 nanocrystals, which improves the separation and migration of photogenerated electron‐hole pairs. As a result, complete photoreduction of Cr(VI) is surprisingly achieved for 2D/2D self‐assembly MoS2/Cu−ZnIn2S4 in 4 min under visible light irradiation (λ≥400 nm) without sacrificing any agents. Moreover, this self‐assembly is further indicated to have a strikingly huge tolerance to high concentration Cr(VI) (250 mg ⋅ L−1), and the photoreduction activity of Cr(VI) is almost not disturbed by high concentration inorganic ions in wastewater. All these merits demonstrate that 2D/2D transition‐metal‐sulfide self‐assembly may find many practical applications in water cleaning and environmental remediation.

Copper incorporation by low-energy ion implantation in PEO-coated additively manufactured Ti6Al4V ELI: Surface microstructure, cytotoxicity and antibacterial behavior

The purpose of this study is to investigate, for the first time, the biocompatibility and antibacterial behavior of coatings obtained by plasma electrolytic oxidation (PEO) on the Ti6Al4V ELI alloy manufactured through the direct metal laser sintering (DMLS) additive manufacturing technique, implanted with two different concentrations of Cu ions by ion plating diversified (IPD). The surface morphology, elemental composition, and phase characteristics of the PEO coatings were investigated by SEM/EDS, GDOES, XRD, and XPS. The cytotoxicity in stem cells and the antibacterial effect were evaluated. The XPS analysis confirmed the successful incorporation of Cu at both concentrations, which appeared in the form of two different chemical components: CuO (92%) and Cu2O (8%). Stem cells were able to adhere and spread on the surface of the Ti6Al4V ELI alloy, with or without PEO coatings and ionic implantation of Cu particles; the materials and coatings were not cytotoxic. Quantitative cell viability assays for Staphylococcus aureus and Pseudomonas aeruginosa bacteria did not show significant differences. However, the staining of the viability wells, mainly for S. aureus, indicates a change in the behavior of these bacteria in coatings that contained the implantation of Cu oxides. This research demonstrated the potential that the union of the properties of the substrate manufactured in additive manufacturing (great versatility), PEO coatings (wear resistance and cell viability), and IPD ion implanted Cu particles can have in different applications.

Construction of antifouling Cu-modified TiO2 coating via micro-arc oxidation: The influence of Cu content

As an effective antimicrobial element, the incorporation of Cu into the surface layer of metallic Ti substrate is regarded as a promising method to enhance its antifouling phenomenon. In this work, a micro-arc oxidation (MAO) process was conducted in an aqueous electrolyte containing Na2Cu-EDTA to produce a Cu-modified TiO2 coating on metallic Ti. The influence of Na2Cu-EDTA concentrations on microstructural feature, corrosion resistance and antifouling capability of the Cu-modified TiO2 coatings were examined. The results indicate that an increased amount of Cu could be incorporated into TiO2 with a higher concentration of Na2Cu-EDTA, which also affects the micro-arc discharge events and, consequently, the morphological features of the coating. The content of incorporated Cu determines the antifouling performance of Cu-modified TiO2 coating, which remains harmless to the corrosion resistance.

Effective enhancement of performances on photo-assisted dye degradation using a Zn coordination polymer and its post-modified Cu/Zn bimetallic analogue under natural environments

A highly stable condensed three-dimensional framework, [Zn(2,6-ndc)(H2O)] (Zn-ndc, 2,6-ndc = naphthalene-2,6-dicarboxylate, CSD entry: MIMRAB; CCDC no: 182255), and its post-modified Cu/Zn bimetallic analogue [CuxZn1−x(2,6-ndc)(H2O)] (CuZn-ndc, x = 0.45 −0.49) showed remarkably catalytic activity to greatly improve the degradation performances of organic dyes including malachite green (MG), methylene blue (MB), and methyl orange (MO) in the presence of H2O2 without and with natural light illumination. The dye degradation over Zn-ndc and CuZn-ndc both followed the order MG > > MB > MO. In addition, CuZn-ndc displayed greater photocatalytic degradation activity compared to Zn-ndc, resulting in faster degradation rate and higher degradation efficiency. Zn-ndc and CuZn-ndc both retained the crystallinity and photocatalytic activity to degrade MG, MB, and MO dyes over five consecutive usages, implying long-term stability and reusability. Of note, pH exerted an effect on the surface charge of Zn-ndc and CuZn-ndc to decrease dye degradation performances of MB and MO but not MG as the decrease of pH. Further, CuZn-ndc had more negative charges on the surface than Zn-ndc, which provided higher affinity toward dyes and thus facilitated dye degradation. Explorations on mechanism provened that the dye degradation was a H2O2-trigged oxidative degradation process, thus more H2O2 dosage led to higher short-term degradation performances. Moreover, incorporation of Cu(II) would significantly reduce band gap energy of photo-assisted catalysts and also lead to a Cu-based photo-Fenton redox cycle, both of which would produce more hydroxyl radicals and photo-generated holes and electrons as active species. This greatly enhanced the photocatalytic activity to improve the performance of dye degradation process.

Copper Doped PPy/MWCNT Nanocomposite Materials for Supercapacitor Applications

We report the structural, morphological, and electrochemical properties of polypyrrole (PPy), copper doped PPy (Cu/PPy), and copper doped polypyrrole multi-walled carbon nanotubes (Cu/PPy/MWCTs) prepared by oxidative polymerization technique. The incorporation of Cu in the form of nanoparticles in the composites was confirmed from XRD data. The granular morphology of PPy was observed from the FESEM micrograph. However, the size of the grains was decreased with Cu nanoparticle insertion in the matrix. The uniform distribution of Cu nanoparticles in the Cu/PPy and Cu/PPy/MWCTs nanocomposites has been evidenced from TEM images. The highest specific capacitance of 311 F/g at a scan rate of 10 mV/s is achieved in the case of Cu/PPy/MWCTs composite. It is found that the cyclic stability of these nanocomposites is enhanced due to the integration of MWCNTS and Cu nanoparticles with PPy polymer. The Cu/PPy/MWCNTs nanocomposites retained 91% of their specific capacitance even after 1000 cycles. The maximum energy density of 19.89 Wh/kg and maximum power density of 4479.71 W/kg at the scan rate of 200 mV/s were also measured for the Cu/PPy/MWCNTs nanocomposite. Our study thus indicates that the prepared Cu/PPy/MWCTs nanocomposite could be a potential candidate for application in supercapacitor and hybrid type storing devices.

Copper and silver heterometallic iodoantimonates: structure, thermal stability, and optical properties.

Seven heterometallic iodoantimonates with the general formula (Cat)2{[Sb2M2I10]} (M = Cu(I) (1-6), Ag(I) (7)) were prepared. X-ray diffraction data indicate that these compounds are the first Sb(III) representatives of the structural type previously known only for heterometallic iodobismuthates(III). In 3 and 4, halogen-substituted cations form halogen bonds with the heterometallic halometalate chain. 1-7 show prominent thermal stability. The estimated optical band gaps lie between 2.16 and 2.40 eV. As in heterometallic iodobismuthates, incorporation of Cu+ rather than Ag+ provides a much lower band gap.