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The paper investigates the structural, optical and photocatalytic activity of large surface area single crystalline copper (Cu) doped SnO2 nanorods (NRs) synthesized by a novel one-step microwave irradiation method. Powder X-ray diffraction (XRD) analysis confirms that both pure and Cu doped SnO2 are tetragonal rutile type structure (space group P42/mnm) formed during the microwave process within 10 min without any post annealing treatment. Transmission electron microscopy (TEM) reveals that the as synthesized Cu doped SnO2 samples exhibited rod-like shape and the length was less than 80 nm and diameter was about few nanometers. Typical selected-area electron diffraction (SAED) pattern indicates that, the growth direction of Cu-SnO2 nanorod is along [110] direction. The variety of phonon interaction in the pure and Cu doped SnO2 is observed by Raman spectroscopy. Electron paramagnetic resonance and X-ray photoelectron spectroscopy (XPS) confirms that the presence of copper and tin as Cu2+ and Sn4+ in state, respectively. The photocatalytic activity was monitored via the degradation of methylene blue (MB) and Rhodamine B (RhB) dyes and the Cu-SnO2 showed better photocatalytic activity than that of pure SnO2. This could be attributed to the effective electron-hole separation by surface modification. [ABSTRACT FROM AUTHOR]

Abstract In order to develop an efficient electrode to remove pharmaceutical and personal care products from wastewater, copper and antimony doped Ti/SnO 2 electrode were prepared by thermal decomposition. Electrochemical characterization was undertaken on Ti/SnO 2 -Cu using cyclic voltammetry and linear sweep voltammetry, indicating an ultra-high 2.1 V of oxygen evolution potential, better stability, and superior corrosion resistance rather than traditional Ti/SnO 2 -Sb electrode. Competitive degradation experiments showed more efficient removal rate was achieved on Ti/SnO 2 -Cu electrode, which could remove more than 90% ceftazidime within 60 min. The microstructure and crystal orientation of the modified electrodes were investigated by scanning electron microscopy, which indicated that the crystal of the Ti/SnO 2 -Cu electrode grew in more porous and uniform condition, covered with closely arranged layers of the coating. X-ray photoelectron spectroscopy and X-ray diffractions suggested that Cu 2 O was successfully coated on the Ti/SnO 2 -Cu electrode surface. The operating parameters of electrochemical degradation process were also investigated, including current density, initial concentration, electrode distance, stirring rate and supporting electrolyte. Consequently, the intermediate products of electrochemical degradation were monitored by liquid chromatography-mass spectrometry and a major degradation pathway was proposed. Highlights • Cu and Sb doped Ti/SnO 2 electrodes were synthesized via thermal decomposition. • Ultra-high oxidation potential and stability were achieved on Ti/SnO 2 -Cu electrode. • Faster removal rate and optimized parameters were shown with Cu doping. • A possible ceftazidime degradation pathway and intermediate products are proposed. [ABSTRACT FROM AUTHOR]

Copper-doped zinc oxide nanoparticles (NPs) CuxZn1−xO (x = 0, 0.01, 0.02, 0.03, and 0.04) were synthesized via a sol-gel process and used as an active electrode material to fabricate a non-enzymatic electrochemical sensor for the detection of glucose. Their structure, composition, and chemical properties were characterized using X-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier-transform infrared (FTIR) and Raman spectroscopies, and zeta potential measurements. The electrochemical characterization of the sensors was studied using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and differential pulse voltammetry (DPV). Cu doping was shown to improve the electrocatalytic activity for the oxidation of glucose, which resulted from the accelerated electron transfer and greatly improved electrochemical conductivity. The experimental conditions for the detection of glucose were optimized: a linear dependence between the glucose concentration and current intensity was established in the range from 1 nM to 100 μM with a limit of detection of 0.7 nM. The proposed sensor exhibited high selectivity for glucose in the presence of various interfering species. The developed sensor was also successfully tested for the detection of glucose in human serum samples.

Pure and Cu doped anatase/rutile mixed TiO _2 nanomaterials were fabricated through sol-gel method. The obtained photocatalysts were characterized by XRD, SEM, TEM, XPS, PL and DRS, and the influences of Cu doping on the structure and photocatalytic property were studied. The results show that when the molar ratios of Cu/Ti are 1% and 2%, Cu doping promotes anatase → rutile phase transformation. When the molar ratio of Cu/Ti is 4%, the phase transformation is inhibited. Cu element coexists in the form of Cu ^+ and Cu ^2+ , and Cu doping facilitates the separation of photogenerated electrons and holes. TEM image shows that copper oxides are dispersed on TiO _2 particles surface, which significantly reduces the optical absorption of ultraviolet region. The photocatalytic experiment results show that the photocatalytic activity of Cu–TiO _2 is lower than pure TiO _2 , and the higher doping concentration, the lower photocatalytic activity.

This work deals with Cu-modified 1DTiO2 microrods (MRs) and their surface properties. The pristine lyophilized precursor Cu_1DTiO2, prepared by an environmentally friendly cryo-lyophilization method, was further annealed in the temperature interval from 500 to 950 °C. The microstructure of all samples was characterized by electron microscopy (SEM/EDS and HRTEM/SAED), X-ray powder diffraction (XRD), infrared spectroscopy, simultaneous DTA/TGA thermoanalytical measurement, and mass spectroscopy (MS). Special attention was paid to the surface structure and porosity. The 1D morphology of all annealed samples was preserved, but their surface roughness varied due to anatase-rutile phase transformation and the change of the nanocrystals habits due to nanocavities formation after releasing of confined ice-water. The introduction of 2 wt.% Cu as electronically active second species significantly reduced the direct bandgap of 1DTiO2 in comparison with undoped TiO2 and the standard Degussa TiO2_P25. All samples were tested for their UV absorption properties and H2 generation by PEC water splitting. We presented a detailed study on the surface characteristics of Cu doped 1DTiO2 MRs due to gain a better idea of their photocatalytic activity.

Safe disposal of excess sewage sludge (SS) produced from chemical/biochemical water treatment processes has been a worldwide concern. In this work, sewage sludge biochar-based Cu-loaded catalysts (CSBC) were synthesized by a simple impregnation-pyrolysis method. The impregnated Cu2+ in SS was converted to Cu0/CuI species after pyrolysis, which greatly improved the removal efficiency of bisphenol A (BPA). BPA (100 mg/L) could be completely removed within 130 min in CSBC/Peroxydisulfate (PDS) system, compared to 77.8% in sewage sludge biochar/PDS system. Meanwhile, CSBC performed well over a wide pH range of 3∼9. In CSBC/PDS system, singlet oxygen (1O 2) dominated non-radical pathway had been proved to play an essential role in BPA degradation, boosting the oxidative treatment of phenolic wastewater under high-salinity. Results showed that the removal efficiency of BPA reached 93.6%, 91.0% and 84.6% in high-salinity wastewater with salinities of 16, 80, and 160 g/L, respectively. The total estimated cost of CSBC (1 kg) was $5.053 and the cost of BPA-containing wastewater (100 mg/L) treatment was estimated approximately 0.02 $/L, indicating its cost-effectively potential in practical applications. This study not only provides a new value-added reuse method for sewage sludge treatment and disposal, but also a new strategy for the effective treatment of high-salinity organic wastewater. [Display omitted] • Cu-doped sludge biochar (CSBC) was fabricated from the sewage sludge. • Singlet oxygen (1O 2) dominated in CSBC/PDS oxidization system. • The loading of Cu species achieved the transition of reactive oxygen species. • CSBC/PDS system has performed well in high-salinity wastewater treatment. [ABSTRACT FROM AUTHOR]

[Display omitted] • The generation and utilization of surface photoinduced oxygen vacancies based on CeO 2. • The optimization of microstructure and doping improved both the generation and consumption of surface photoinduced oxygen vacancies. • DFT calculation compared the reactivity of three main faces for pure & Cu-doped CeO 2 to explain the effect of microstructure. • The improvement of surface photoinduced oxygen vacancies increased the H 2 yield of the photo-thermochemical reaction. Photo-thermochemical (PTC) reaction produces hydrogen by water splitting through the consumption of surface photoinduced oxygen vacancies (V O s). In this study, CeO 2 and Cu-doped-CeO 2 were synthesized with typical different morphologies of nanorods and nanospheres and different crystallite sizes. These factors, i.e. microstructure, crystalline size and Cu doping were proven to influence the physical properties and photoresponse performance of CeO 2 which affected the generation of surface photoinduced V O s and their reactions of hydrogen production in PTC. Cu-doped CeO 2 nanospheres with smaller crystallite size demonstrated the best catalytic activity with the largest H 2 yield of 18.4 μmol g-1h−1. The electron paramagnetic resonance and Ultraviolet–visible diffuse reflection spectroscopy analysis showed that the V O s generation of nanospheres was strengthened compared to nanorods when the physical characteristics were similar. The positive correlation between the change in physical properties and yield supports its importance in V O s consumption in the thermochemical process. The smaller crystallite size of the nanospheres exhibited better porous properties and specific surface area, which facilitated thermochemical reaction. The doping significantly reduces the band gap of the sample, enhances the light absorption capacity and significantly increases the H 2 yield of CeO 2. [ABSTRACT FROM AUTHOR]

• The Cu doped tubular Bi 12 ov was synthesized by a hydrothermal method. • The oxygen vacancies (ov) could increase charge density and reaction sites, while Cu doping could serve as a Fenton-like reagent. • Cu doped Bi 12 ov exhibited a preferable Fenton catalytic rate which was 4.5 times higher than pure photocatalytic degradation. • Detailed degradation mechanism for tetracycline in Cu doped Bi 12 ov system was proposed. Fenton photocatalyst constructed by transition metal-doped semiconductor material seems to be a promising alternative to classic Fenton catalysts. A series of Cu-doped tubular Bi 12 O 17 Cl 2 with sufficient oxygen vacancies (ov) was successfully prepared through a hydrothermal method. The formation of ov in the Bi 12 crystal lattice can favor the Fenton reaction not only by serving as a reaction site and increasing the charge density in the photocatalyst but also by partially reducing the dopant Cu2+ to Cu+, which consequently enhances the H 2 O 2 activation to a significantly higher rate. Notably, Cu-doped Bi 12 O 17 Cl 2 ov with an optimal dopant proportion of 4 % exhibited a preferable Fenton catalytic rate 4.5 times higher than pure photocatalytic degradation. This work investigates the mutual promotion of oxygen vacancies and dopant ions in the Fenton reaction and provides a novel development scheme for the advanced oxidation process. Cu doped Bi 12 O 17 Cl 2 with oxygen vacancies exhibited excellent photodegradation activity with the presence of H 2 O 2 demonstrating the successful fabrication of Cu-based Fenton-like system. [Display omitted] [ABSTRACT FROM AUTHOR]

Developing highly efficient, affordable and renewable electrocatalysts is greatly important for large-scale production of hydrogen. MoS 2 has been regarded as a promising electrocatalyst for hydrogen evolution reaction (HER). Foreign atom doping and forming heterogeneous structure have been proved to be the efficient ways to improve its electrocatalytic performance. In this paper, Cu doped MoS 2 nanosheets supported on NiS 2 (Cu-MoS 2 /NiS 2) nanowires are prepared via the electrospinning, sulfuration and subsequent hydrothermal process. Benefitting from the heterointerfaces and foreign Cu atoms doping, the as-synthesized Cu-MoS 2 /NiS 2 hybrid nanowires possess more electrocatalytic active sites and a favorable synergistic effect compared to the MoS 2 nanoflowers, NiS 2 nanowires and MoS 2 /NiS 2 hybrid structure. The Cu-MoS 2 /NiS 2 hybrid nanowires exhibit an excellent HER performance with a low overpotential of 56 mV (105 mV) at 10 mA/cm2 and a small Tafel slope of 49 mV/dec (59 mV/dec) in 0.5 M H 2 SO 4 (1 M KOH). It is a potential substitute for noble metal electrocatalysts in the future. [Display omitted] • A facile method has been used to fabricate 1D Cu-MoS 2 /NiS 2 hybrid nanowires. • 1D Cu-MoS 2 /NiS 2 hybrid nanowires exhibited an excellent HER performance. • Cu doping could activate inert sites and optimize electronic structure of MoS 2. [ABSTRACT FROM AUTHOR]

One-dimensional (1D) Cu-doped WO 3 nanowires (NWs) were synthesized through the electrospinning process and calcination treatment. Taking the doping amount of 5% for example, the average length and diameter of the prepared 1D NWs were 15 μm and 150 nm, respectively. One part of the doped Cu2+ occupied the position of W6+ in the WO 3 lattice, and the other part separated out Cu 2 O/CuO phases, forming p–n heterojunctions with WO 3 , during the high-temperature calcination. The gas-sensing test results demonstrated that Cu2+ doping significantly improved the material's gas-sensitive properties, and the 5% Cu/WO 3 NWs exhibited the best performance. Specifically speaking, the response of 5% Cu/WO 3 NWs to 100 ppm triethylamine (TEA) at 180 °C was 108, and the response time was 33 s, both of which were superior to those of pristine WO 3 NWs (10, 60 s) at 220 °C. Additionally, the 5% Cu/WO 3 NWs based sensor displayed a good TEA selectivity. In addition to TEA, its second-most sensitive gas was acetone, for which the response could reach 28, but still was only a third of that for TEA. Finally, the theory explaining the sensing mechanism was proposed based on the related characterization results. • The realization of high-performance triethylamine sensing via the prepared Cu doped WO 3 nanowires in electrospinning method. • The 5% Cu/WO 3 sensor showed high response, low theoretical detection limit, and tendentious selectivity toward triethylamine. • The intrinsic mechanism was rationally elucidated for the triethylamine sensing improvement by Cu doping. [ABSTRACT FROM AUTHOR]

CO2 hydrogenation to methanol is one of the main and valuable catalytic reactions applied on Cu/ZnO-based catalysts; the interface formed through Zn migration from ZnO support to the surface of Cu nanoparticle (ZnOx-Cu NP-ZnO) has been reported to account for methanol synthesis from CO2 hydrogenation. However, the accompanied reverse water gas shift (RWGS) reaction significantly decreases methanol selectivity and deactivates catalysts soon. Inhibition of RWGS is thus of great importance to afford high yield of methanol. The clear understanding of the reactivity of RWGS reaction on both the direct contact Cu-ZnO interface and ZnOx-Cu NP-ZnO interface is essential to reveal the low methanol selectivity in CO2 hydrogenation to methanol and look for efficient catalysts for RWGS reaction. Cu doped plate ZnO (ZnO:XCu) model catalysts were prepared through a hydrothermal method to simulate direct contact Cu-ZnO interface and plate ZnO supported 1 wt % Cu (1Cu/ZnO) catalyst was prepared by wet impregnation for comparison in RWGS reaction. Electron paramagnetic resonance (EPR), XRD, SEM, Raman, hydrogen temperature-programmed reduction (H2-TPR) and CO2 temperature-programmed desorption (CO2-TPD) were employed to characterize these catalysts. The characterization results confirmed that Cu incorporated into ZnO lattice and finally formed direct contact Cu-ZnO interface after H2 reduction. The catalytic performance revealed that direct contact Cu-ZnO interface displays inferior RWGS reaction reactivity at reaction temperature lower than 500 °C, compared with the ZnOx-Cu NP-ZnO interface; however, it is more stable at reaction temperature higher than 500 °C, enables ZnO:XCu model catalysts superior catalytic activity to that of 1Cu/ZnO. This finding will facilitate the designing of robust and efficient catalysts for both CO2 hydrogenation to methanol and RWGS reactions.

Highlights • In-situ Cu(II) doped in framework of mesoporous MnO 2 , Cu-MnO 2 was prepared. • Cu-MnO 2 had good catalytic activity and stability for phenol degradation by PMS. • Exposed surface oxygen defect was responsible to the enhancement of PMS activation. Abstract Cu(II) doped mesoporous MnO 2 (Cu-MnO 2) was prepared to establish an intimate functional link between the structure substitution and catalytic peroxymonosulfate (PMS) activation. Based on the characterization of powder X-ray diffraction (XRD), N 2 adsorption-desorption measurement, scanning electron microscope (FE-SEM) and transmission electron microscope (TEM), Cu-MnO 2 had a typical long range ordered mesoporous structure and Cu was successfully introduced in octahedral framework. It exhibited excellent catalytic activity and stability for the phenol degradation by PMS. Phenol was always efficiently degraded over Cu-MnO 2 at a pH range of 3.5–9.0. For example, the reaction rate constant at pH 7.0 was 0.073 min−1, which was two times higher than that of MnO 2 (0.039 min−1). Importantly, 1O 2 was identified as the primary reactive species in Cu-MnO 2 /PMS system. X-ray photoelectron spectroscopy (XPS) confirmed that more exposed surface oxygen defects due to Cu doping were responsible to the enhancement of PMS activation for phenol degradation. The results of PMS decomposition and oxygen evolution indicated that surface oxygen defects lower the reaction energy barrier of PMS decomposition by generating 1O 2 via the energy trapping by oxygen. Finally, the heterogeneous PMS activation mechanism over Cu-MnO 2 was proposed. [ABSTRACT FROM AUTHOR]

We reported an effective method to synthesize In2S3 and Cu-doped In2S3 two-dimensional ultrathin nanoflakes by the hydrothermal method through tuning the Cu/In molar ratio. The transmission electron microscope images showed that the products had ultrathin flake-like shape with wrinkling and rolling. The X-ray diffraction patterns indicated the crystal phase of nanoflakes was varied from β-In2S3 to tetragonal-CuInS2 as the Cu/In molar ratio was increased. The In2S3 nanoflakes exhibited absorption band at 450 nm, while new absorption peaks in turn appeared at 550 nm and 670 nm as the Cu/In molar ratio was increased. In addition, the two-dimensional ultrathin nanoflakes exhibited intense photocurrent response. [ABSTRACT FROM AUTHOR]

The metal-organic framework (MOF) materials, MIL-101(Cr), and copper-doped MIL-101(Cr) (Cu@MIL-101(Cr)) were prepared through hydrothermal method and were used to remove volatile organic compounds (VOCs) in this study. Morphological characterization demonstrated that MIL-101(Cr) and Cu-3@MIL-101(Cr) were octahedral crystal, with specific surface area of 3367 and 2518 m2/g, respectively. The results of XRD, TG, and FTIR showed that the copper doping procedure would not alter the skeleton structure, but it would affect the crystallinity and thermal stability of MIL-101(Cr). Besides, MIL-101(Cr) and Cu-3@MIL-101(Cr) displayed good removal efficiencies on benzene sorption, and the maximum sorption capacity was 103.4 and 114.4 mg/g, respectively. In competitive adsorptions, the order of adsorption priority on Cu-3@MIL-101(Cr) was as follows: ethylbenzene > toluene > benzene. Hence, it could be concluded that MIL-101(Cr) and copper-doped MIL-101(Cr) demonstrated good performance in VOCs adsorption and showed a promising potential for large-scale applications in the removal of VOCs.ᅟ [ABSTRACT FROM AUTHOR]

Tin selenide (SnSe) has been explored as a promising anode material for sodium ion batteries (SIBs) but its electrochemical performance is strictly limited by the large volume variation during charge/discharge process and relatively low electronic conductivity. In this work, hierarchical Cu doped SnSe nanoclusters were prepared by a cost-efficient and nontoxic method and demonstrated as a high-performance anode for SIBs. Under optimized Cu doping degree (10 wt% Cu), the developed Cu-SnSe anode exhibits excellent rate performance with a high capacity of 330 mAh/g at 20 A/g and outstanding stability with a capacity of 304 mAh/g after 1000 cycles at 5 A/g (0.1–3.0 V vs. Na/Na + ). The enhanced electronic conductivity, facilitated sodiation/desodiation process, and relieved volume change during cycling in Cu doped SnSe benefited from Cu doping and the unique hierarchical structure should account for its extraordinary sodiun storage performance. [ABSTRACT FROM AUTHOR]

Chemoresistive toxic gas sensors nowadays are being used exhaustively for maintaining healthy air quality. In this paper, we report synthesis of ordered hierarchical CuxNi(1−x)O nanostructure (average diameter of (400–600 nm))-based sensing layer for chemoresistive toxic gas sensing application. The selectivity of the sensor was found to be temperature tunable. It was sensitive to humidity (response 212% with 90% RH) at room temperature and volatile organic compounds (VOCs) [response towards Ethanol (28%), Methanol (34%), Acetone (25%), and Toluene (44%) at 550 ppm] at 300 °C. The cross sensitivity of the device for VOCs at 300 °C was addressed by performing a low computationally complex clustering technique to define the zone of clear selectivity for each VOC. It was also observed that on sampling the continuous signal with Fast Fourier Transform increases the clustering efficiency by removing the background noise from the sensing transients. The response and recovery times of the sensor (for all analytes) ranged in tens of seconds with good repeatability and stability. Thus, the sensor device so fabricated is expected to serve as a commercially viable temperature tunable and selective gas sensor. [ABSTRACT FROM AUTHOR]

The structural and electrochemical performance of Cu-doped, Li[Ni1/3−xCo1/3Mn1/3Cux]O2 (x = 0-0.1) cathode materials obtained by means of the sol--gel method are discussed; we used critic acid as gels and spent mixed batteries as the raw materials. The effects of the sintering time, sintering temperature, and Cu doping ratio on the phase structure, morphology, and element composition and the behavior in a galvanostatical charge/discharge test have been systemically studied. The results show that the Cu-doped material exhibits better galvanostatic charge/discharge cycling performance. At 0.2 C, its original discharge specific capacity is 180.4 mAh g−1 and its Coulomb efficiency is 90.3%. The Cu-doped material demonstrate an outstanding specific capacity at 0.2 C, 0.5 C, and 2.0 C. In comparison with the original capacities of 178 mAh g−1, 159.5 mAh g−1, and 119.4 mAh g−1, the discharge capacity after 50 cycles is 160.8 mAh g−1, 143.4 mAh g−1, and 90.1 mAh g−1, respectively. This obvious improvement relative to bare Li[Ni1/3Co1/3Mn1/3]O2 cathode materials arises from an enlarged Li layer spacing and a reduced degree of cation mixing. Therefore, Cu-doped cathode materials have obvious advantages in the field of lithium-ion batteries and their applications. [ABSTRACT FROM AUTHOR]

Highly transparent Cu doped ZnO thin films were deposited on glass substrates by spray pyrolysis technique. Crystallinity of the films improved at lower doping concentrations due to the easy fitting of Cu dopants in the Zn Lattice sites and preferred highly textured growth along the (002) plane. Higher doping concentration deteriorated the crystallinity and the optical transmission followed the similar trend. EDX spectra analysis confirmed the incorporation of Cu in the doped films. Optical energy gap red-shifted with the addition of Cu contents due to the exchange interactions and difference in iconicity of Zn and Cu. Cu doped films exhibited strong visible emission due to the modulation of the band structure and subsequently new levels acting as emission centres will be formed in the forbidden gap of ZnO. Moreover, the addition of Cu dopants increases the concentration of zinc interstitials as well as zinc and oxygen vacancies which cause more intense emission in the visible region. Cu doped films exhibited excellent photocatalytic activity due to the efficient trapping of photo-generated electrons thereby suppressing the electron-hole recombination and higher doping level slightly decreased the degradation efficiency because excess dopants may act as recombination centres. [ABSTRACT FROM AUTHOR]

A series of Cu-doped LiNi 0.5 Mn 1.5−x Cu x O 4 (x = 0, 0.03, 0.05, 0.10, 0.15) spinel samples have been successfully prepared using a modified low temperature solution combustion synthesis method. X-ray diffraction(XRD) and infrared spectroscopy(FT-IR) analysis are used to characterize the phase structure. Scanning electron microscopy(SEM) is used to observe the microstructure of the products. The electrochemical performance are studied by galvanostatic charge-discharge testing, cyclic voltammetry(CV) and electrochemical impedance spectroscopy(EIS). No obvious secondary phases were observed in XRD patterns of as-synthesized LiNi 0.5 Mn 1.5−x Cu x O 4 powders. The samples have a combination structure of ordered and disordered space group and the order degree increases with the increase of Cu doping content obtained from FT-IR spectra. The electrochemical performances show that although the specific capacity decreases with the Cu-doping content, the cycle-life both at room temperature and 55 °C and the C-rate performance are remarkably improved. The factors of stable structure, grain refinement, better crystallinity and lower charge transfer resistance lead to the excellent performance of Cu-doped samples. [ABSTRACT FROM AUTHOR]

Cu was incorporated into Bi 2 Te 2.85 Se 0.15 compound as a dopant, and the microstructure and thermoelectric properties of sintered Cu x Bi 2 Te 2.85 Se 0.15 samples have been investigated. The Cu atoms intercalated into interstitial sites along the c -axis, which caused an increase in lattice constant c . The accommodation of Cu in Bi 2 Te 2.85 Se 0.15 reached saturation at x = 0.05 and the excessive Cu formed a copper telluride compound. The interstitial Cu resulted in decreases in carrier concentration and phonon thermal conductivity as well as an increase in carrier mobility. A maximum ZT value was obtained at x = 0.05, which was enhanced for about 4 times compared to Cu-free sample. [ABSTRACT FROM AUTHOR]

The intrinsic peroxidase-like activity of magnetite magnetic nanoparticles (Fe 3 O 4 MNPs) has to be improved to activate H 2 O 2 under mild conditions for practical applications. Herein copper-doped Fe 3 O 4 (Fe 3−x Cu x O 4 , x: 0.06–0.23) MNPs were successfully prepared by oxidative precipitation-combined ionothermal synthesis and characterized by XRD, VSM, XPS, BET, etc. The Cu 2+ dopants are mainly substituted for Fe 2+ ions at octahedral sites and significantly surface-enriched, which expedite the Fe 3+ /Fe 2+ redox cycling and enhance the H 2 O 2 -activation ability of Fe 3−x Cu x O 4 MNPs. Kinetic study showed that the decomposition of H 2 O 2 on Fe 2.88 Cu 0.12 O 4 was much faster than that on the undoped Fe 3 O 4 (0.584 vs. 0.153 h −1 at 25 °C) due to the lower activation energy of the former (55.3 vs. 62.1 kJ/mol). The enhanced H 2 O 2 -activation ability upon copper doping was exploited to efficiently degrade recalcitrant organic pollutants (e.g., rhodamine B) with H 2 O 2 at pH ∼ 7 and 25 °C on Fe 2.88 Cu 0.12 O 4 with good stability and reusability (16 h tested in eight cycles). [ABSTRACT FROM AUTHOR]

A diopside based bioactive system with a nominal composition of xCuO-(45.55-x)CaO-29.44 SiO 2 -10.28P 2 O 5 -14.73 MgO (x = 0,1,3 and 5 mol%) has been prepared by sol gel technique in the laboratory. X-ray Diffraction, Fourier Transform Infra-Red and Raman Spectroscopy, Field Emission Scanning Electron Microscopy along with Energy Dispersive X-ray Analysis and pH studies have been undertaken on the prepared samples before and after dipping the samples in simulated body fluid. It has been observed that hydroxyapatite layer starts to form with in 24 h during immersion in simulated body fluid. Degradation studies have also been employed to check the degradation behavior in Tris-HCl. Dynamic light scattering studies show that particles are mostly agglomerated and have an average size of 356 nm. Zeta potential studies have been undertaken to check the surface charge and it has been estimated that samples carry negative charge when dipped in simulated body fluid. Negative surface charge may contribute to attachment and proliferation of osteoblasts. Samples have also shown the antimicrobial properties against the Vibro cholerae and Escherichia coli pathogens. To check the non-toxic nature of the samples, cell cytotoxic and cell culture studies have been undertaken using the MG-63 cell lines. Samples have shown good response with good percentage viability of the cells in the culture media and hence, provides friendly environment to the growth of cells. The particle size, bioactivity, negative values of zeta potential, antimicrobial properties and good cell viability indicate the potential of the synthesized compositions as possible candidates for bone repair applications. [ABSTRACT FROM AUTHOR]

The metastable cubic γ phase Ga 2 O 3 with a defect spinel structure presents several fascinating properties, which may be a more attractive material than the stable β form. Herein, we found that the metastable γ -Ga 2 O 3 can be stabilized by copper (Cu) doping through a simple operation and low cost method of sol-gel. The γ -Ga 2 O 3 thin films were prepared under the annealing of 700 °C in nitrogen atmosphere for Cu doping. The β phase Ga 2 O 3 ones were obtained at the same condition without the Cu dopant. While the Cu doped γ phase Ga 2 O 3 will transform to β phase for a high annealing temperature above 800 °C. The grain size of Cu doped γ -Ga 2 O 3 and undoped β -Ga 2 O 3 thin films increases with the increase of the annealing temperature. The UV–Vis absorption spectrum of the β -Ga 2 O 3 thin film exhibits a sharp intrinsic absorption edge at ∼250 nm, whilst Cu doped γ -Ga 2 O 3 thin film displays an obvious red-shift. The band gap decreases from 4.90 eV to 4.38 eV for the Cu doping. The photoluminescence intensity at the ultraviolet and blue region of Cu doped γ- Ga 2 O 3 thin films are stronger than undoped β -Ga 2 O 3 , which can be attributed to the introduction of more defects such as oxygen vacancies in γ phase by Cu doping. [ABSTRACT FROM AUTHOR]

Copper doping in polycrystalline CdTe thin films and optimal band alignment at the CdTe/back-contact interface are critical for obtaining high performance devices. A CuCl 2 solution treatment was used in this work to enhance the p-doping of CdTe. The carrier density of CdTe was increased from 4.72 × 10 13 to 1.11 × 10 14 cm −3 and the open circuit voltage of the device was obviously improved more than ~50 mV from 728 to 783 mV. In order to further improve device performance, Te/Cu bilayer using rapid thermal processing was implemented to reduce barrier at the back contact. The short time-high temperature process efficiently activated the Te/Cu bilayer back contact and precisely controlled the Cu diffusion. The proper dose of Cu diffusion can further increase the p-doping of CdTe (~2.22 × 10 14 cm −3 ), resulting in the apparent increase in response from the CdS spectral region. The chemical reaction occurred between Te and Cu after rapid thermal processing treatments causing the formation of the Cu x Te phases, which can form a barrier in the conduction band to reflect electrons and reduce recombination at the back contact. With the increase of the temperature, the open circuit voltage of the device increased. However, the device with excessive Cu contacted at higher temperature showed the reduction in response in the long-wavelength region and decrease in fill factor due to the formation of much more Cu-related recombination states. Finally, open circuit voltage of > 820 mV, and fill factor of > 72% for CdTe solar cells with an area of 0.24 cm 2 were achieved. [ABSTRACT FROM AUTHOR]

The effect of calcination temperature ( TC = 500-1000 °C) and cooling rate on the dopant distribution in Cu-doped Y-stabilized ZrO2 nanopowders is studied. The powders are produced by co-precipitation technique and investigated by attenuated total reflection, UV-vis diffuse reflectance, electron paramagnetic resonance, and transmission electron microscopy methods. The cooling rate is found to affect the amount of Cu substances on grain surface, the powders subjected to fast cooling (quenching) showed higher amount of Cu-related complexes on the grains' surface than their counterparts cooled with furnace after calcination. It is observed that Cu impurities diffuse inside ZrO2 grains from Cu-related surface substances when TC < 800 °C. This process is accompanied by the enhancement of 275-nm absorption band caused by oxygen vacancies formation. For TC > 800 °C, outward migration of Cu dopants takes place. Simultaneously, the intensity of 275-nm absorption band decreases, the monoclinic ZrO2 phase forms and its contribution rises with TC. It is proposed that monoclinic phase formation is caused by the replacement of Cu atoms from lattice sites to interstitials leading to an appearance of the channels for Y out-diffusion via cation vacancies and destabilization of ZrO2 tetragonal phase. [ABSTRACT FROM AUTHOR]

• Cu doped MoS 2 were fabricated for CO 2 hydrogenation to methanol. • Cu doped in MoS 2 increases the amounts of sulfur vacancies of MoS 2. • The Cu doped MoS 2 exhibits excellent performance at low temperature. • The mechanism of hydrogenation of Cu-MoS 2 was revealed by in-situ FTIR spectra. Hydrogenation of CO 2 to methanol is one of effective ways to promote "carbon neutrality". The activity of MoS 2 as an efficient catalyst for the catalytic hydrogenation of CO 2 to methanol is influenced by the content of in-plane S vacancies. Theoretically, the higher the density of in-plane S vacancies is, the better the performance of the catalyst is. In this work, a series of MoS 2 nanosheets with different copper (Cu) dopant concentrations were prepared via hydrothermal method. It was found that the highest selectivity of MoS 2 -catalyzed CO 2 hydrogenation to methanol along with the spatial-temporal yield was achieved at the Cu doping of 5%. Compared to the undoped MoS 2 catalyst, the increase in methanol selectivity and spatial-temporal yield after doping was 13.37% and 2.27 times, respectively. This was due to the fact that Cu doping multiplied the number of S vacancies on MoS 2 , which altered the microstructure and chemical properties of the catalyst. However, a further increase in Cu dopant concentration reduced the S vacancy content on the MoS 2 substrate, hindering the hydrogenation of the decomposed CO and thus decreasing the methanol yield. Therefore, a new technique to enhance MoS 2 -catalyzed CO 2 hydrogenation to methanol was proposed. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] • The exposed surface atoms of catalyst were tuned by facet control, doping and promoter modification. • The CO 2 hydrogenation performance of facet-control Fe-S was obviously better than that of Fe-R. • The abundant oxygen vacancy on Fe-S was beneficial to enhance the adsorption and activation of CO 2. • Cu doping and K promoter had synergistic promoting effect on the C-C bond coupling. • 3 K/6Cu-Fe-S exhibited a record-high C 5+ yield of 23.6% Hydrogenation of CO 2 into liquid hydrocarbons is an attractive route for chemical utilization of CO 2 , but suffers from limited product selectivity. By controlling the exposed surface atoms of metal catalyst, purposefully enhancing the reaction rate of bottleneck steps for CO 2 activation and C-C coupling is expected to solve this problem. Here, we tuned the exposed surface atoms of catalysts separately and simultaneously by facet control, doping and promoter modification; a nanosheet-shaped Fe 2 O 3 rich in oxygen vacancies was first constructed to enhance the adsorption and activation of CO 2. Cu doping and K promoter were further used to promote the formation of active χ-Fe 5 C 2 phase and facilitate the coupling of C-C bond to form long chain fuels. The optimized K-promoted and Cu-doped Fe 2 O 3 nanosheets (3 K/6Cu-Fe-S) exhibited high CO 2 conversion (46.5%) and C 5+ hydrocarbons selectivity (53.6%), accompanied with low CO (5.3%) and CH 4 selectivity (12.2%) at 300 °C, outperforming other reported Fe-based catalysts significantly. Meanwhile, a 205 h on stream test indicated the excellent stability of 3 K/6Cu-Fe-S. The effects of each tuning method on catalytic activity and product selectivity were further studied by combining the change of the phase and surface electronic structure of the catalyst before and after the reaction. Cu doping and K promoter were verified to have a synergistic enhancement effect on the hydrogenation performance of CO 2 , rather than just the sum of the two. These findings would be beneficial for the rational design of CO 2 hydrogenation catalysts. [ABSTRACT FROM AUTHOR]

Defects engineering in metal oxide is an important avenue for the promotion of VOCs catalytic oxidation. Herein, the influence of crystal facet of Co 3 O 4 is first investigated for the propane oxidation. An intelligent Cu doping is subsequently performed in the most active (110) facet exposed Co 3 O 4 catalyst. The optimized Cu-Co 3 O 4 -110–3 catalyst exhibits a prominently enhanced activity with propane conversion rate of 1.9 μmol g−1 s−1 at reaction temperature of 192 °C and the propane mass space velocity of 60,000 mL g−1 h−1, about 2.4 times that of the pristine Co 3 O 4. Systematic experimental characterizations (XAS, EPR, Raman, TPR, XPS, etc.) combined with density functional theory calculations point out that the incorporated Cu could increase the electrophilicity of nearby O atom and implant beneficial defect structures (lattice distortion, coordination unsaturation, abundant oxygen vacancies, etc.), which could significantly activate Co-O bond in Co 3 O 4 , leading to the facilitated generation of active oxygen species as well as promoted oxidation ability. This study could set an illuminating paradigm for the boost of the intrinsic oxidation activity by the precise defect construction in Co 3 O 4 catalyst, which will help drive ahead the pursuit of non-precious metal catalyst for VOCs abatement. [Display omitted] • (110) facet of Co 3 O 4 is more active for propane oxidation than other facet exposed ones. • Cu doping in (110) facet of Co 3 O 4 help further boost the propane oxidation activity. • Cu doping can stimulate Co-O activation by defect structure engineering and O electrophilicity modulation. [ABSTRACT FROM AUTHOR]

[Display omitted] • Cu doped Fe 2 O 3 in-situ growing on a nickel foam was successfully fabricated. • Cu doping lead to an apparently enhanced catalytic efficiency of Fe 2 O 3 /NF. • 100% of SD can be removed in 10 min in the VL + EC + 2Cu-Fe 2 O 3 /NF + PMS system. • Cu-Fe 2 O 3 /NF exhibited excellent durability and recycle ability. In this study, cost-effective and easily recovery Cu doped Fe 2 O 3 in-situ growing on a nickel foam (Cu-Fe 2 O 3 /NF) was successfully fabricated and employed in peroxymonosulfate (PMS) assisting visible-light photoelectrochemical oxidation (VL + EC + catalyst + PMS) system for sulfadiazine (SD) removal. The optimum 2Cu-Fe 2 O 3 /NF exhibited excellent catalytic efficiency toward SD degradation in the VL + EC + catalyst + PMS system, 100% of SD being removed in 10 min and the firs-order reaction kinetic constant being 41.30 × 10-2 min−1. The excellent catalytic efficiency of 2Cu-Fe 2 O 3 /NF was due to the depressed recombination of photoinduced electron and hole, the enhanced electron transfer efficiency, more Fe2+, Cu+ and Ni2+ in sample resulting from Cu doping, and more active sites owing to the bulk thick petals-like of Fe 2 O 3 being changed to thinner flakes after Cu doping. Therefore, a large number of reactive oxygen species including •OH, •O 2 − and h+ in the VL + EC + 2Cu-Fe 2 O 3 /NF + PMS system were produced to degrade SD. The mechanism of SD degradation in the system was explored in detail. The 2Cu-Fe 2 O 3 /NF displayed adaptation ability for a wide range, good anti-interference ability toward ions in real water. More inspiring, benefiting from the in-situ growth of Cu-Fe 2 O 3 on NF surface, 2Cu-Fe 2 O 3 /NF exhibited good durability and recycle ability. This study provides a worthy reference for designing efficient and easily recycled catalysts and promotes the practical application possibility of low-cost Fe 2 O 3 in antibiotics removal. [ABSTRACT FROM AUTHOR]

[Display omitted] • Through vacuum arc melting, a series of Cu doping Ti-Mn-based AB 2 -type alloys are obtained. • Cu doping enlarges the crystal cells of the alloys and increases the hydrogen storage capacity of the alloys. • The alloys with Cu doping can improve the activation performance, reduce hysteresis coefficient and optimize cycle life. • First-principles Simulations prove that Cu doping is beneficial to the hydrogen storage properties. • The introduction of Cu to optimize the properties of hydrogen storage alloys is universal. The Ti-Mn-based AB 2 -type hydrogen storage alloy has been widely researched and applied because of their higher hydrogen storage capacity, appropriate service temperature and low cost. However, before this hydrogen storage material becomes a mature technology, the essential issues of activation difficulty and high plateau pressure in hydrogen absorption/desorption process, need to be completely reformed by radical transformation in composition design and structure optimization. This work investigates the microstructure and hydrogen storage performances of Ti 0.8 Zr 0.2 Mn 0.92 Cr 0.87 Fe 0.21 + x Cu (x = 0, 3, 5 and 8 wt%) by vacuum arc melting. Profiting from the excellent hydrogen transfer rate and structure optimization, the Ti 0.8 Zr 0.2 Mn 0.92 Cr 0.87 Fe 0.21 alloys with the increasing of Cu doping result in the unique C14 Laves phase with the increased lattice volume. As a beneficial result, the decrease of the hydrogen absorption platform of Ti 0.8 Zr 0.2 Mn 0.92 Cr 0.87 Fe 0.21 + 8 wt% Cu alloy is accompanied by the increase of the hydrogen desorption platform, thereby reducing the overall hysteresis coefficient of the material. Through Van't Hoff thermodynamic calculation results, it is found that the absolute values of hydrogenation enthalpy and entropy increase with the increasing of Cu doping. It is crucial to doping Cu inside the alloy by the accurate control of stoichiometric proportion and Cu content, which can improve the hydrogen storage performance of the alloy through theoretical analysis and First-principles simulation. This attempt enables new insights into the optimization of the hydrogen storage properties of Ti-Mn-based AB 2 -type hydrogen storage alloy, which can be generalized to the design of other new hydrogen storage materials. [ABSTRACT FROM AUTHOR]

The doping of transition metal ions, such as Cu+ and Mn2+ into a quantum dot (QD) host is one of the useful strategies in tuning its photoluminescence (PL). This study reports on a two-step synthesis of Cu-doped InP QDs double-shelled with ZnSe inner shell/ZnS outer shell. As a consequence of the double shelling-associated effective surface passivation along with optimal doping concentrations, Cu-doped InP/ZnSe/ZnS (InP:Cu/ZnSe/ZnS) QDs yield single Cu dopant-related emissions with high PL quantum yields of 57−58%. This study further attempted to tune PL of Cu-doped QDs through the variation of InP core size, which was implemented by adopting different types of Zn halide used in core synthesis. As the first application of doped InP QDs as electroluminescent (EL) emitters, two representative InP:Cu/ZnSe/ZnS QDs with different Cu concentrations were then employed as active emitting layers of all-solution-processed, multilayered QD-light-emitting diodes (QLEDs) with the state-of-the-art hybrid combination of organic hole transport layer plus inorganic electron transport layers. The EL performances, such as luminance and efficiencies of the resulting QLEDs with different Cu doping concentrations, were compared and discussed.