Formation Of Cu Research Articles

Nanosensors Monitor Intracellular GSH Depletion: GSH Triggers Cu(II) for Tumor Imaging and Inhibition.

Glutathione (GSH) is the primary antioxidant in cells, and GSH consumption will break the redox balance in cells. Based on this, a method that uses high concentrations of GSH in the tumor microenvironment to trigger the redox reaction of Cu(II) to generate copper nanoprobes with fluorescence and tumor growth inhibition properties is proposed. The nanoprobe mainly exists in the form of Cu(I) and catalyzes the decomposition of hydrogen peroxide into hydroxyl radicals. At the same time, a simple and controllable carbon micro-nano electrode is used to construct a single-cell sensing platform, which enable the detection of glutathione content in single living cells after Cu(II) treatment, providing an excellent example for detecting single-cell biomolecules.

Temperature-induced changes in DTPA-extractable trace elements: Predicting the potential impact of climate change on the availability of soil elements

The extraction of trace elements from soil with DTPA is a widely used protocol across laboratories. There is a possible “hidden” discrepancy regarding the results obtained from the extractions, i.e., ambient laboratory temperature and soil properties. In this study, the possible influence of these factors on the extractability of the available forms of Cu, Fe, Pb, Mn, Ni, and Zn, measured with DTPA were studied. Α series of extractions was carried out on a soil sample under normal laboratory temperatures, which fluctuated throughout the year, from 15 to 33.9 °C. In other 144 soil samples, the prevailing physico-chemical properties of soil were evaluated (pH, organic C, clay, CaCO3) that affected the percentage of DTPA extractability relative to the pseudo-total determined content. A strong positive correlation of all metals versus increased ambient temperature was found. Cu had an R2 of 0.897, Fe 0.970, Mn 0.957, Ni 0.938, Pb 0.876, and, Zn 0.922, all highly significant. Extracted Mn exhibited a 6.5-fold increase at the highest temperature of 33.9 οC compared to the lowest. Similar increasing trend was observed for Fe, and Ni, and smaller for Cu, Zn, and Pb. Inherent soil properties affected the percentage of extractability relative to the total content: extractability of Cu, Fe, Mn, and Ni was affected negatively by pH, and the extractability of the studied metals with CaCO3 content. Other soil properties (organic C and clay/sand content) also had an effect, not as pronounced as that of pH and CaCO3. This signifies the necessity of employing standard conditions for routine extractions such as DTPA so that data may be comparable. Also these identified discrepancies may have consequences in the extractability and availability of soil micronutrients and toxic elements regarding climate change. This study aspires to play the role of an initial step towards more robust investigations that would suggest ways of correcting temperature and soil characteristics discrepancies across laboratories.

The influence of SRB on corrosion behavior of Cu-based medium-entropy alloy coating sprayed by HVOF

In this study, a novel Cu-based (Cu55Al20Ni12Ti8Si5, at.%) medium-entropy alloy (MEA) coating was prepared by high-velocity oxygen-fuel (HVOF) spraying technology. Thermo-Calc was employed to simulate the phase diagram of the alloy system. Phase composition and microstructure of the as-sprayed coating were characterized by means of XRD, FESEM, TEM and STEM/EDX. The effect of sulfate-reducing bacteria (SRB) on the corrosion behavior of the coating and the as-cast Ni-Al bronze (NAB) was investigated using electrochemical measurements and surface characterization. The Thermo-Cala simulation results showed that the alloy system presented a single BCC solid solution phase, while the detailed characterization of microstructure indicated that a few NiTi-rich B2-ordered precipitates could be also found in the as-sprayed coating other than the Cu-rich BCC matrix. Electrochemical studies illustrated that the coating exhibited superior corrosion resistance than the NAB in SRB medium, the corrosion acceleration efficiency induced by SRB of the NAB (95.3 %) was more severe than that of the coating (63.8 %). Surface analysis results demonstrated the occurrence of pitting corrosion and the formation of Cu2S on the coating surface after corroded in SRB medium. Corrosive metabolite HS- induced microbiologically influenced corrosion was considered as the main corrosion acceleration mechanism caused by SRB.

Synergy between copper and cobalt on 3D Co/CuO complex promotes peroxymonosulfate activation

Activation of peroxymonosulfate (PMS) to degrade refractory antibiotics is an essential branch of advanced oxidation processes (AOPs). We reported in this study that the (111) and (002) crystal planes of CuO with the (311) crystal plane of Cu0.72Co2.28O4 formed surface heterojunctions, which are used as interfaces for PMS adsorption to explore the performance of different heterojunctions. The formation of Cu0.72Co2.28O4/CuO heterojunction makes up for the CuO (002) surface’s shortcomings and improves the adsorption and activation of PMS by the CuO (002) surface. The heterojunction significantly grows the length of the PMS’ O-O bond compared to the single-crystal surface, which leads to lower energy required for PMS’ O-O bond breaking and further verified the increased covalent character. Based on the quality influencing factors values, the influence of four factors on sulfamethoxazole (SMX) deterioration fits as follows: HCO3– has the largest relative relevance among the factors, followed by H2PO4-, NO3–, and Cl-. The Box-Behnken methodology fitted the optimum efficiency with the initial concentration of Cl-, NO3–, H2PO4-, and HCO3– were 8.0, 10.0, 12.5, and 7.5 mM, respectively. The SMX’s atoms (N, and O) have higher electrophilic attack sites, indicating these atoms are electrophilic attack sites.

The investigation of the binding ability between sodium dodecyl sulfate and Cu (II) in urban stormwater runoff

The simultaneous presence of heavy metals and surfactants in runoff induces complexation and ecological harm during migration. However, interactions between these pollutants are often overlooked in past studies. Thus, investigating heavy metal-surfactant complexes in runoff is imperative. In this work, Cu (II) and sodium dodecyl sulfate (SDS) were selected to investigate the interaction between heavy metals and surfactants due to the higher detected frequency in runoff. Through 1H NMR and FTIR observation of hydrogen atom nuclear displacement and functional group displacement of SDS, the change of SDS and Cu (II) complexation was obtained, and then the complexation form of Cu (II) and SDS was verified. The results showed that solution pH values and ionic strength had significant effects on the complexation of Cu (II). When the pH values increase from 3.0 to 6.0, the complexation efficiency of SDS with Cu (II) increased by 12.12% at low concentration of SDS, which may be attributed to the excessive protonation in the aqueous solution at acidic condition. The increase of ionic strength would inhibit the complexation reaction efficiency by 19.57% and finally reached the platform with concentration of NaNO3 was 0.10 mmol/L, which was mainly due to the competitive relationship between Na (I) and Cu (II). As a general filtering material in stormwater treatment measures, natural zeolite could affect the interaction between SDS and Cu (II) greatly. After the addition of SDS, the content of free Cu (II) in the zeolite-SDS-Cu (II) three-phase mixed system was significantly reduced, indicating that SDS had a positive effect on the removal of Cu (II) from runoff. This study is of great significance for investigating the migration and transformation mechanism of SDS and Cu (II) in the future and studying the control technology of storm runoff pollution.

286 The Effect of Dietary Copper Levels and Source on the Performance and Profitability of Finishing Pigs

Abstract The micronutrient copper (Cu) is known to improve performance variables and the overall health of livestock animals. Different responses have been reported based on the molecular form of Cu and the inclusion level supplemented to growing pigs. The objective of this experiment was to evaluate four inclusion levels (25 ppm, 75 ppm, 125 ppm, 175 ppm) of CuSO4 and two Cu sources tribasic Cu chloride and organic Cu, in performance variables and economics of production of pigs during the grower-finisher phases. This trial was conducted at the Baynesfield Swine Research Unit at Baynsefield Estate in KwaZulu Natal, South Africa, following local farm protocols. A total of 528 animals (70 d of age; Initial BW of 33.1 ± 0.31 kg; TN 70 Topig Genetics) were randomly allotted to 48 mixed sex pens, with 11 pigs/pen. The treatments were as follow: TRT1 25 ppm CuSO4, TRT2 75 ppm CuSO4, TRT3 125 ppm CuSO4, TRT4 175 CuSO4, TRT5 hydroxy Cu, and TRT6 organic Cu. Each treatment had 8 repetitions with an equal number of boars and gilts (44). A four-phase corn and soy-based diet were formulated on the same specs having the premixes altered to accommodate the four Cu levels and/or Cu sources. Experimental animals had ad libitum access to feed and water. Feed intake and body weight were measured at every phase change. Additionally, the carcass variables (lean meat %, grading, cold carcass weight, and dressing%) were measured at slaughter. Feed cost, carcass value, MOFC, and cost per gain were calculated to determine economic value for each treatment. Statistical analysis was conducted in SAS (2021) utilizing the Proc GLM model for the average effects within each period, and if significant (P < 0.05) the Fisher’s test was used for LSMeans. There were no significant differences between the dietary treatments for BW, ADFI, ADG, FCR, or yield (Table 1). However, cost over feed was greater for the TRT6 fed pigs compared with either the TRT2 or TRT3 treatments but similar to the other treatments (P < 0.05). But when considering margin over feed, there were no significant differences amongst the treatments. In conclusion, this trial did not demonstrate an economic advantage of feeding copper greater than 75 ppm or utilizing alternative forms of copper.

Highly sensitive and selective ratiometric fluorescent and visual detection of Cu2+ based on the hydroxytyrosol–naphthoresorcin–quantum dots sensing platform

Fluorescence-based visual analysis has attracted considerable attention in on-site detection owing to their distinct color gradient changes, easy operation and high sensitivity. In this work, we construct an exceptionally simple dual-emission ratio fluorescence sensor through the synergy of hydroxytyrosol (HYT), naphthoresorcin (NR) and ZnCdSe/ZnS quantum dots (QDs), namely HYT–NR–QD, for the fluorescent and visual detection of Cu2+. The design of ratiometric nanosensor is based on our new finding that Cu2+ can catalyze the reaction between HYT and NR to produce a cyan-emitting fluorophore (emission: 480 nm), and the copper species existed in the form of Cu+ and Cu2+ in reaction system. After adding QDs (emission: 605 nm), the free Cu+, Cu2+ and the resulting fluorophore in this system caused a great reduction in the FL intensity of QDs, due to the rapid cation exchange reaction between QDs and Cu2+/Cu+ as well as the inner filter effect between QDs and the resulting fluorophore. Overall, Cu2+ induced emission intensity changes at 480 and 605 nm leads to a distinct color change from red to cyan. A ratiometric fluorescence Cu2+ sensor with a lowest concentration of 3.42 nM was developed. Furthermore, the concentration of Cu2+ can be conveniently reflected with a smartphone application by identifying the RGB value. Moreover, the method proposed by us can be explored for Cu2+ determination in environmental water samples with a satisfying result, providing a novel, simple-operating and on-site detection of Cu2+ in water samples.

Mechanical activation mechanism of cassiterite based on copper-based grinding media

During grinding, the abrasion and corrosion of the grinding media generate metal ions, thereby affecting mineral flotation separation. In this study, the mechanical activation mechanism of cassiterite by copper-based media was investigated via grinding and micro-flotation experiments, inductively coupled plasma optical emission spectroscopy (ICP-OES), solution chemistry calculations, X-ray photoelectron spectroscopy (XPS) and Density functional theory (DFT). Compared with ceramic medium, copper-based medium enhanced the grinding technical efficiency of cassiterite and improved the flotation recovery. Mechanism study revealed that the increase Cu ions content in the pulp of cassiterite grinding products was the main contributor to the mechanical activation of cassiterite by copper-based grinding media, and the main forms of Cu in the solution were Cu2+, Cu(OH)+ and Cu(OH)2. XPS results demonstrated that the Cu components adsorbed on the surface of cassiterite as Cu(II) and Cu–O groups. Meanwhile, DFT calculation results shown that the Cu components were spontaneously adsorbed on the surface of cassiterite (110) in the following order: CuOH+ < Cu(OH)2 < Cu2+. Therefore, the adsorption capacity of BHA increased. These results indicate an improvement in the flotation behavior of cassiterite mechanically activated by copper-based grinding media.

Heavy Metals in Sediments of Subarctic Meromictic Lakes of the White Sea as Possible Tracers of Environmental Changes

Meromictic lakes of the marine coast, quite widely distributed in the northern hemisphere, are the result of climate changes and glacier retreat. The bottom sediments of these lakes serve as a geological chronicle of the history of marine basin’s development with the geochemical occurrence forms of elements indicate various processes of their accumulation. This paper presents research results concerning the occurrence of forms of heavy metals in lake sediments along the coast of the White Sea. These results are based on a sequential seven step leaching procedure, followed by ICP-MS analysis and subsequent statistical data processing. To determine differences among the examined geochemical parameters, Pearson’s correlation analysis and Ward’s cluster analysis were utilized. The total content of Cr, Mn, Fe, Co, Ni, Zn, V, and Pb in the sediments did not exhibit significant differences based on their degree of isolation from the sea. The major contribution to deposition of these metals in sediments of the meromictic lakes studied is the residual form, encompassing the mineral matrix of the sediment. At the same time, the elevation of mobile forms for all the metals examined corresponds to an increase in the isolation of lakes from the White Sea. In the meromictic lake sediments, concentrations of Cu, Mo, and U demonstrated significant increases in forms tightly bound to organic matter, while Cd exhibited an association with Fe-Mn oxyhydroxides. Notably, a significant difference in the occurrence forms of Cu, Cd, Mo, and U was evident in the reduced sediments of meromictic lakes when compared to those of open sea bays. The meromictic lakes along the White Sea coast, positioned at various stages of isolation, hold promise for investigating the migration of metals in response to environmental changes.

Adsorption of Gold from Copper–Tartrate–ThiosulfateSolutions with Ion-Exchange Resins

The adsorption behavior of gold from copper–tartrate–thiosulfate solutions with ion-exchange resins was studied in this paper. Experimental parameters include resin dosage, pH, temperature, copper, tartrate, and thiosulfate concentration. A moderate increase in resin dosage, pH, temperature, and tartrate concentration is beneficial for gold adsorption, but an excessive tartrate concentration or higher temperature depresses the adsorption process. Increasing copper and thiosulfate concentrations may competitively occupy the active sites on the resin surface, leading to a reduction in the gold adsorption capacity. The XPS and FT-IR analyses indicate that copper and gold on the resin after adsorption mainly exist in the form of Cu+ and Au+, and sulfur mainly exists in the form of SO42− and S2O32−. This implies that the use of resin for gold recovery from thiosulfate leachate may face critical challenges because there is inevitably a higher content of copper and thiosulfate.

Correlating the Valence State with the Adsorption Behavior of a Cu-Based Electrocatalyst for Furfural Oxidation with Anodic Hydrogen Production Reaction.

The low-potential furfural oxidation reaction (FFOR) on a Cu-based electrocatalyst can produce H2 at the anode, thereby providing a bipolar H2 production system with an ultra-low cell voltage. However, the intrinsic activity and stability of the Cu-based electrocatalyst for the FFOR remain unsatisfactory for practical applications. This study investigates the correlation between the valence state and the adsorption behavior of the Cu-based electrocatalyst in furfural oxidation. Cu0 is the adsorption site with low intrinsic activity. Cu+ , which exist in the form of Cu(OH)ads in alkaline electrolyte, has no adsorption ability but can improve the performance of Cu0 by promoting adsorption of FF. Moreover, a mixed-valence Cu-based electrocatalyst (MV Cu) with high intrinsic activity and stability is prepared electrochemically. With the MV Cu catalyst, the assembled dual-side H2 production electrolyzer has a low electricity requirement of only 0.24 kWh·mH2 -3 at an ultra-low cell voltage of 0.3V, and it exhibits sufficient stability. This study not only correlates the valence state with the adsorption behavior of the Cu-based electrocatalyst for the low-potential FFOR with anodic H2 production but also reveals the mechanism of deactivation to provide design principles for Cu-based electrocatalysts with satisfactory stability. This article is protected by copyright. All rights reserved.

Cu2(OH)3Cl microspheres with self-assembled nanostructures through a dissolution regulation reaction and exhibits excellent antibacterial activity

Basic copper chloride (Cu2(OH)3Cl) microspheres with different surface nanostructure were synthesized via the dissolution regulation of calcite in CuCl2 solution. We studied the influence of CuCl2 concentration, reaction time and reaction temperature on the formation of Cu2(OH)3Cl, and the products were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, field emission scanning electron microscopy and transmission electron microscopy. The concentration of CuCl2 has a great influence on the dissolution rate of calcite, dispersed microsphere particles assembled by nano-blocks formed in 20 mM CuCl2 solution. The surface of Cu2(OH)3Cl microsphere change from nano-block to nano-rod with increasing the reaction time from 20 min to 2 h Cu2(OH)3Cl microspheres with surface structure changed from nano-sheet, nano-plate to nano-block with the reaction temperature increase from 37 °C to 70 °C. The Cu2(OH)3Cl microsphere also displays superior antibacterial properties against S. aureus and E. coli. This work displays a new strategy to synthesize functional materials by the use of dissolution regulation methods.

The ecological assessment of the purity of medicinal plant raw materials &lt;i&gt;Thymus serpyllum&lt;/i&gt; L. in the Trans-Urals of the Republic of Bashkortostan

The paper presents the results of the study of heavy metals content in plant raw materials Thymus serpyllum L. growing in the vicinity of the village of Arkaim, Sibay, the Republic of Bashkortostan. The content of mobile forms of Cu, Ni, Mn, Co, Fe, Cd in soils did not exceed the maximum permissible concentrations, with the exception of Zn (1,87 MPC) and Pb (3,16 MPC). It was found that the most mobile element in the soil was Pb (59,4%), while Ni (0,07%) was less mobile. The soils of the studied territory were classified as permissible according to the degree of pollution, and the ecological situation turned out to be relatively satisfactory. The results of the statistical analysis showed that the concentrations of heavy metals in plant ash had a high variability (above 21%), with the exception of Co, which was characterized by an average variability (up to 20%). Cu content in Thymus serpyllum L. plants did not exceed acceptable values. There were exceeding of the maximum permissible levels for Zn (3,889,72 times), Fe (6,457,9 times), Ni (108189 times), Cd (1,162,16 times), Co (3,75,6 times), Pb (4,610,8 times) in all organs of the plant Thymus serpyllum L. Mn concentrations exceeded the norms in the stems and roots of the species by 1,514,48 times, respectively. The most absorbed by plants Thymus serpyllum L. elements turned out to be Fe and Ni. In plants Thymus serpyllum L. Fe (124,3) and Ni (1567,5) belonged to the group of elements of energetic accumulation (IA 10), Zn (8,12), while Cu (8,04), Mn (4,44), Pb (2,08), Cd (1,75), Co (1,31) belonged to the group of elements of strong accumulations (IA 110). In plants of Thymus serpyllum L. Cu, Zn, Ni, Fe, Mn, Pb were distributed by acropetal type (acropetal coefficient 1,0), while Cd, Co were distributed by basipetal type (acropetal coefficient 1,0).

Metal oxide nanoparticles embedded in porous carbon for sulfur absorption under hydrothermal conditions

MOx (M = Zn, Cu, Mn, Fe, Ce) nanoparticles (NPs) embedded in porous C with uniform diameter and dispersion were synthesized, with potential application as S-absorbents to protect catalysts from S-poisoning in catalytic hydrothermal gasification (cHTG) of biomass. S-absorption performance of MOx/C was evaluated by reacting the materials with diethyl disulfide at HTG conditions (450 °C, 30 MPa, 15 min). Their S-absorption capacity followed the order CuOx/C > CeOx/C ≈ ZnO/C > MnOx/C > FeOx/C. S was absorbed in the first four through the formation of Cu1.8S, Ce2S3, ZnS, and MnS, respectively, with a capacity of 0.17, 0.12, 0.11, and 0.09 molS molM−1. The structure of MOx/C (M = Zn, Cu, Mn) evolved significantly during S-absorption reaction, with the formation of larger agglomerates and separation of MOx particles from porous C. The formation of ZnS NPs and their aggregation in place of hexagonal ZnO crystals indicate a dissolution/precipitation mechanism. Note that aggregated ZnS NPs barely sinter under these conditions. Cu(0) showed a preferential sulfidation over Cu2O, the sulfidation of the latter seemingly following the same mechanism as for ZnO. In contrast, FeOx/C and CeOx/C showed remarkable structural stability with their NPs well-dispersed within the C matrix after reaction. MOx dissolution in water (from liquid to supercritical state) was modeled and a correlation between solubility and particle growth was found, comforting the hypothesis of the importance of an Ostwald ripening mechanism. CeOx/C with high structural stability and promising S-absorption capacity was suggested as a promising bulk absorbent for sulfides in cHTG of biomass.

Identifying the Local Atomic Environment of the "Cu3+" State in Alkaline Electrochemical Systems.

CuO-based catalysts are active for the oxygen evolution reaction (OER), although the active form of copper for the OER is still unknown. We combine operando Raman experiments and density functional theory (DFT) electronic structure calculations to determine the form of Cu(O)xOHy present under OER conditions. Raman spectra show a distinct feature related to the active "Cu3+" species, which is only present under highly oxidizing conditions. DFT is used to produce theoretical Raman standards and match the unique Raman feature of copper under OER potentials. This method identifies a range of Cu3+-containing compounds which match the distinct Raman feature. We then integrate experimental electrochemistry to progressively eliminate possible structures and determine the stoichiometry of the active form as CuOOH, which likely takes the form of a surface-adsorbed hydroxide on a CuO surface. Bader charge analysis, site-projected wavefunctions, and density of states analysis show that electron density is removed from O 2p orbitals upon hydroxide adsorption, suggesting that the electronic structure exhibits d9L Cu2+ behavior rather than the local electronic structure of a formal Cu3+.

In Operando Photoswitching of Cu Oxidation States in Cu-Based Plasmonic Heterogeneous Photocatalysis for Efficient H2 Evolution.

Metal nanoparticles (NP) supported on TiO2 are known to be efficient photocatalysts for solar-to-chemical energy conversion. While TiO2 decorated with copper NPs has the potential to become an attractive system, the poor oxidative stability of Cu severely limits its applicability. In this work, we demonstrate that, when Cu NPs supported on TiO2 nanobelts (NBs) are engaged in the photocatalytic generation of H2 from water under light illumination, Cu is not only oxidized in CuO but also dissolved under the form of Cu+/Cu2+ ions, leading to a continuous reconstruction of nanoparticles via Ostwald ripening. By nanoencapsulating the CuOx (Cu/CuO/Cu2O) NPs by a few layers of carbon supported on TiO2 (TC@C), Ostwald ripening can be suppressed. Simultaneously, the resulting CuOx@C NPs are photoreduced under light illumination to generate Cu@C NPs. This photoswitching strategy allows the preparation of a Cu plasmonic photocatalyst with enhanced activity for H2 production. Remarkably, the photocatalyst is even active when illuminated with visible light, indicating a clear plasmonic enhancement of photocatalytic activity from the surface plasmonic resonance (SPR) effect of Cu NPs. Three-dimensional electromagnetic wave-frequency domain (3D-EWFD) simulations were conducted to confirm the SPR enhancement. This advance bodes for the development of scalable multifunctional Cu-based plasmonic photocatalysts for solar energy transfer.

Flame Aerosol Synthesis of Metal Sulfides at High Temperature in Oxygen Lean Atmosphere.

The development of a novel reactive spray technology based on the well-known gas phase metal oxide synthesis route provides innumerable opportunities for the production of non-oxide nanoparticles. Among these materials, metal sulfides are expected to have a high impact especially in the development of electrochemical and photochemical high surface area materials. As a proof-of-principle, MnS, CoS, Cu2 S, ZnS, Ag2 S, In2 S3 , SnS, and Bi2 S3 were synthesized in an O2 -lean and sulfur-rich environment. In addition, the formation of Cu2 S in a single droplet combustion experiment, is reported. The multi-scale approach combining flame sprays with single droplet combustion is expected to pave the way towards a fundamental understanding of the gas phase formation of metal sulfides in the future. The knowledge acquired will open the possibility for the development of a next generation gas-phase technology facilitating the scalable synthesis of functional binary/ternary metal sulfides. This article is protected by copyright. All rights reserved.

Dual color luminescence of Mn2+ doped lead-free Cs3Cu2I5 perovskite phosphors and their LED solid-state lighting and anti-counterfeiting applications

Cs3Cu2I5 have recently attracted far-flung and fervency interests with the characters of low cost, high photoluminescence quantum yield, green and non-toxicity. In addition, continuous tuning of the luminescence properties could be realized in Cs3Cu2I5, which would benefit its optical applications. Herein, Mn2+ is chosen as the luminescent center into Cs3Cu2I5 through solid-state ball milling method. Its structure and photoluminescence properties have been studied by various characterization methods such as X-ray powder diffractions, fluorescence spectroscopy, and element mapping. These results showed that Mn2+ doping into Cs3Cu2I5 makes little change on the crystal structure of Cs3Cu2I5. The copper ions and manganese ions exist stably in the form of Cu+ and Mn2+, respectively. After Mn2+ doping, a new emission peak appears at 560 nm except for the intrinsic blue emission of Cs3Cu2I5, thus realizing dual color luminescence. This material also exhibits excellent thermal stability, making it suitable for solid-state lighting and anti-counterfeiting applications.

Adsorption and Sequential Extraction of Copper in Technosols Prepared from Unconsolidated Mining Wastes Rich in Limestone, Bentonite, and Organic Matter

In this work the adsorption and immobilization of copper ions of four different Technosols constructed with wastes were tested. These soils were made from mixtures of limestone wastes, organic matter, sand, and bentonite. The methods used were “batch” and columns experiments, where the soils were in contact with a Copper (Cu) rich solution for 24 h and afterwards for 24-weeks. Total concentration of adsorbed Cu, sequential extraction in the Technosols and Cu concentration in the leachates were evaluated. The results showed that the Technosols have high efficiency to rapidly immobilize Cu ions, and the percentage of adsorption varied between 87 and 99% in the batch experiment after 24 h. The sequential extraction showed that the materials used in the construction of technosols demonstrated high affinity for the metal, especially the carbonates and organic matter, which adsorbed 14–16% and 10–16% respectively of total Cu added via solution. However, most of the adsorbed Cu was found in the residual fraction (50–64%), which represented the less labile form of Cu. These results demonstrate that in addition to adsorb great part of the Cu added via solution, the Technosols immobilize Cu in a highly stable form, representing a great option for the reclamation of contaminated-Cu areas. However, the decrease in pH with time (24 weeks) showed a strong influence on the adsorption of Cu in Technosols, influencing the amount of leached copper. We therefore recommend the design of Technosols with limestone wastes, bentonite, and organic matter with periodical control of pH for fast and efficient retention of Cu.

WITHDRAWN: Effects of pH on Ochrobactrum immobilises heavy metals during fly ash–sludge​ co-pyrolysis

In order to determine the optimal pH at which Ochrobactrum immobilises heavy metals during fly ash-sludge co-pyrolysis, we investigated the effects of pH on Ochrobactrum to adsorb or desorb heavy metals. The metallic forms of copper (Cu), zinc (Zn), and manganese (Mn) under different pH conditions during co-pyrolysis were analysed using the sequential extraction procedure (BCR). The stabilising mechanisms of Cu, Zn, and Mn caused by Ochrobactrum under different pH conditions during co-pyrolysis were characterised with Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD). Results indicated the following: (1) The heavy metals immobilised by Ochrobactrum were significantly affected by pH during fly ash-sludge co-pyrolysis. (2) The stable forms of Cu, Zn, and Mn increased most noticeably under neutral and weak alkaline conditions. (3) The neutral and weak alkaline conditions favoured the formation of crystallised materials as well as the preservation of chemical bonds. The results suggested that the effects of Ochrobactrum on the immobilisation of Cu, Zn, and Mn under neutral and weak alkaline conditions were optimal. The results of the study can provide a reference and basis for the harmless disposal of municipal sludge and fly ash and the efficient utilisation of Ochrobactrum . • pH had an effect on Ochrobactrum during fly ash-sludge co-pyrolysis. • pH 7 and pH 9 could improve the stabilisation of heavy metals by Ochrobactrum . • pH 7 and pH 9 could promote the preservation of the chemical bonds by Ochrobactrum . • pH 7 and pH 9 could promote the formation of crystallised materials by Ochrobactrum .