Mechanism Of Cu Research Articles

Corrosion-erosion behavior and mechanism of Cu[sbnd]Mo co-doped CoCrFeNi high-entropy alloy coating prepared by directed energy deposition

Developing cost-effective and high-performance high-entropy alloy (HEA) coatings on demand is imperative. This study designed a class of HEAs on-demand by synergistic doping of Cu and Mo elements based on the first-principles and multi-principal alloy design concept. A CoCrFeNiCu0.25Mo0.75 HEA coating with outstanding corrosion and slurry erosion wear performances was fabricated on the duplex stainless steel using the directed energy deposition technique. The corrosion mechanism of the HEA coating in 3.5 % NaCl and 0.5 M H2SO4 solutions and the slurry erosion wear mechanism under a slurry concentration of 5 wt% were analyzed in combination with the density functional theory. The results indicate that the SQS crystal model is a better predictor of phases and properties of HEA than the VCA model. The HEA coating is a cellular structure that consists mainly of a face-centered cubic phase structure and contains a small amount of homogeneous sigma nanocrystalline secondary phase precipitation. Meanwhile, the passive film of the HEA coating is mainly composed of metal oxides and hydroxides. Cu is not oxidized during the corrosion process and always exists in the metallic form, which serves as a barrier layer to prevent the transfer of point defects. Mo with a larger atomic size can induce lattice distortion, enhance the coating strength and hardness, and reduce the density of point defects. Further, the slurry erosion wear rate of the HEA coating is lower at a 30° impingement angle than 90° for brittle erosion mode. At the 30° impingement angle, micro-cutting and ploughing are the main wear mechanisms of the HEA coating, while at the 90° impingement angle, micro-indents and craters are the main wear mechanisms. In addition, the corrosion and slurry erosion wear performances of CoCrFeNiCu0.25Mo0.75 HEA coating are better than the most reported once-formed HEAs.

Exposure to copper activates mitophagy and endoplasmic reticulum stress-mediated apoptosis in chicken (Gallus gallus) cerebrum.

A large amount of copper (Cu) used in production activities can lead to the enrichment of Cu in the environment, which can cause toxicity to animals. However, the toxicity mechanism of Cu on the cerebrum is still uncertain. Hence, a total of 240 chickens were separated into four groups in this study to reveal the potential connection between mitophagy and endoplasmic reticulum (ER) stress-mediated apoptosis in the chicken cerebrum in the case of excess Cu exposure. The cu exposure situation was simulated by diets containing various levels of copper (11 mg/kg, control group; 110 mg/kg, group I; 220 mg/kg, group II and 330 mg/kg, group III) for 49 days. The results of histology showed that vacuolar degeneration was observed in the treated groups, and the mitochondria swell and autophagosomes formation were found under excess Cu treatment. Additionally, the expression of mitophagy (PINK1, Parkin, LC3I, LC3II and p62) and ER stress (GRP78, PERK, ATF6, IRE1α, XBP1, CHOP, and JNK) indexes were significantly upregulated under excess Cu exposure. Furthermore, the mRNA and protein expression of Bcl-2 were decreased, while Bak1, Bax, Caspase12, and Caspase3 were increased compared to the control group. In summary, this study demonstrated that an overdose of Cu could induce mitophagy and ER stress-mediated apoptosis in the chicken cerebrum. These findings revealed an important potential connection between Cu toxicity and cerebrum damage, which provided a new insight into Cu neurotoxicity.

A detailed investigation on the phase transformation mechanism during electroplating of Cu (In, Ga) Se2 films on FTO-glass substrates

In this study, an attempt has been made to acquire an in-depth understanding of the electroplating mechanism of Cu (In, Ga) Se2 quaternary thin films on FTO-glass substrates. A systematic approach starting with the study of unitary, binary, ternary, and finally quaternary deposition of the elements have been performed through cyclic voltammetry (CV). The salts used were CuCl2, H2SeO3, InCl3 and GaCl3 for each stage of deposition with varying combinations and proportions. CVs were first done for unitary Cu, Se, In and Ga elements, then binary combinations of Cu-In, Cu-Se, Cu-Ga, In-Se, In-Ga, and Se-Ga system, ternary baths of Cu-In-Se and Cu-In-Ga, In-Se-Ga and Cu-Se-Ga systems, and finally quaternary Cu-In-Ga-Se system. An optimum deposition potential of −0.65 V was chosen from the position of cathodic peaks for all the baths. A thorough structural and elemental analysis, defect densities, type of conductivity was carried out for the as-deposited films. Single step deposition of CIGS was found to be impossible, hence Ga was attempted to incorporate in the films through a two-stack approach. From the position and intensity of the cathodic peaks and the phase analysis, plausible mechanism has been proposed for the quaternary alloy.

Remediation mechanism of Cu, Zn, As, Cd, and Pb contaminated soil by biochar-supported nanoscale zero-valent iron and its impact on soil enzyme activity

Recently, heavy metal contaminated soil has been widespread concerned. Herein, rice straw-derived biochar-supported nanoscale zero-valent iron (nZVI@BC) composite was prepared and characterized, and its remediation performance in Cu, Zn, As, Cd, and Pb contaminated soil were evaluated. nZVI@BC demonstrated better immobilization effect on multiple heavy metals than biochar, and the residual component of Cu, Zn, As, Cd, and Pb increased by 10.27%, 7.18%, 7.44%, 9.26%, and 12.75%, respectively. After nZVI@BC treatment, the soil pH, the available iron, cation exchange capacity, total organic carbon, and dissolved organic carbon increased. Besides, soil enzyme (catalase, urease, and fluorescein diacetate hydrolase) activities significantly increased, especially, the catalase activity was doubled. Furthermore, the immobilization mechanism was explored, including surface adsorption, electrostatic attraction, ion exchange, coprecipitation, oxidation-reduction, and complexation. Additionally, the adsorption sites of Pb and Cu were more competitive, and As synergistically promoted the adsorption of Pb, forming a ternary surface complex PbFeAsO4OH. Therefore, it well demonstrates that nZVI@BC may be a potential technology for remediation of multiple heavy metals contaminated soil.

Synthesis of Cu–TiO2/CuS p-n heterojunction via in situ sulfidation for highly efficient photocatalytic NO removal

Cu doped TiO2/CuS (Cu–TiO2/CuS) p-n heterojunction was synthesized via in situ sulfidation method for efficient photocatalytic removal of NO at ppb-level. The results show that optimized Cu–TiO2/CuS heterojunction possessed a maximum efficiency of 85% for the removal of NO under visible light irradiation, which was approximately 8.5, 4.3 and 1.2 times that of CuS, TiO2 and Cu–TiO2, respectively. The improved photocatalytic performance is attributed to the enhancement of visible light absorption and charge carrier separation induced by the construction of p-n heterojunction. Meanwhile, the p-n heterojunction charge transfer mechanism of Cu–TiO2/CuS was verified by systematic investigations. The appropriate band structures of the two components and the internal electric field formed at the interface of the heterojunction were two factors for this charge transfer mechanism. Furthermore, the role of active species in NO removal was explored, and the corresponding mechanism for NO removal of the heterojunction was proposed. This work provides a promising approach for the synthesis of heterojunction photocatalysts and facilitates the application of photocatalysts in sustainable and efficient pollutant removal.

Removal of Copper(II) from Aqueous Environment Using Silk Sericin-Derived Carbon.

Sericin is a by-product of the silk industry. Its recycling contributes to environmental protection and the sustainable development of the cocoon silk industry. In this paper, on the basis of realizing sericin enrichment in solution, the Cu(II) adsorption capacities of sericin-derived carbon (SC), prepared at different pyrolysis temperatures, were studied. SC was characterized using scanning electron microscopy (SEM) and the zeta potential. The effects of the initial concentration of Cu(II), pH, adsorption temperature, and contact time on the adsorption process were evaluated, followed by an investigation of the mechanism of Cu(II) adsorption by SC. The results showed that SC has a porous structure that provides sites for Cu(II) adsorption. The maximum adsorption capacity of Cu(II) onto SC1050, 17.97 mg/g, was obtained at an adsorption temperature of 35 °C and a pH of 5.5. In addition, the pseudo-second-order kinetic model and Langmuir isotherm model correctly described the adsorption process of Cu(II) onto SC1050. Therefore, SC can act as a potential adsorbent for removing Cu(II) from water. This study helps promote the effective use of cocoon silk resources.

Effects of copper exposure on lipid metabolism and SREBP pathway in the Chinese mitten crab Eriocheir sinensis

Copper (Cu) is not only a common metal pollutant in the aquatic environment but also an essential trace element for aquatic organisms such as the Chinese mitten crab (Eriocheir sinensis). Cu is known to regulate lipid metabolism yet exert toxic effects if ingested in excess. However, the molecular regulatory roles of Cu in the lipid metabolism of crabs remains unclear. Thus, this study investigated the potential regulatory mechanism of Cu onto lipid metabolism of E. sinensis following acute Cu exposure. Crabs were exposed to environmental concentration of Cu (50 μg/L) for 96 h, and the expression of sterol regulatory element binding protein (SREBP) was knocked down by RNA interference (RNAi) to test its effect on Cu exposure. The results showed that RNAi significantly attenuated the Cu exposure-induced increase in lipid synthesis and triglycerides (TG) hydrolysis, while significantly inhibited the Cu exposure-induced decrease in fatty acid β-oxidation, suggesting that SREBP is involved in Cu-induced lipid metabolism. Subsequent analyses of the transcriptome results further revealed potential responsive genes of SREBP that were linked to lipid metabolism and immune regulation. Moreover, Cu may affect lipid metabolism through the TOR-SREBP pathway in E. sinensis. This work provides a reference for exploring the effects of Cu on lipid metabolism disorders in crustaceans.

Adsorptive removal of Cu(II) from aqueous solution by fermented sweet sorghum residues as a novel biosorbent

Sweet sorghum straw is a kind of natural wood cellulose with high porosity and high specific surface, which is theoretically conducive to the physical adsorption of heavy metal ions. In this paper, we reported a new biosorbent, the fermented sweet sorghum residues (FSSR), which is a byproduct of bioethanol production by fermentation of sweet sorghum straw, for the removal of Cu(II) from aqueous solution. The properties of the adsorption of Cu(II) on SSR and FSSR were studied and compared. The adsorption process of Cu(II) by SSR and FSSR conformed to the Elovich kinetic model. The isothermal adsorption process conformed to the Freundlich and the Tempkin models. The adsorption capacity of FSSR for Cu(II) was increased with the increase of pH. The adsorption mechanism of Cu(II) by FSSR was mainly attributed to ion exchange. SSR and FSSR were characterized by SEM-EDS, FTIR and XRD. The surface of FSSR had microporous structure, the content of –OH and other active functional groups increased. The fermentation has a certain destructive effect on the crystal structure of cellulose with the increase of amorphous structure. Therefore, fermentation process could be regarded as an effective means of microbial modification, to destroy the structure of the straw and result in the porous structure, which improved the adsorption capacity of SSR for heavy metals. FSSR could be used as a potential biosorbent for heavy metal removal from aqueous solution. Ethanol fermentation might be an effective method to improve performance of biosorbent for Cu adsorption.

Electrochemical Reduction and Preparation of Cu-Se Thermoelectric Thin Film in Solutions with PEG.

Investigation of Cu(II) and Se(IV) electrochemical reduction processes in solutions with poly(ethylene glycol) (PEG) provides important theoretical guidance for the preparation of Cu-Se alloy films with stronger thermoelectric properties. The results reveal that PEG adsorbing on the electrode surface does not affect the electrochemical reduction mechanism of Cu(II), Se(IV), and Cu(II)-Se(IV), but inhibits the electrochemical reduction rates. The surface morphology and composition change with a negative shift in the deposition potentials. The Cu-Se alloy film, which was prepared at 0.04 V, was α-Cu2Se as-deposited and P-type thermoelectric material after annealing. The highest thermoelectric properties were as follows: Seebeck coefficient (α) was +106 μV·K−1 and 1.89 times of Cu-Se alloy film electrodeposited in Cu(II)-Se(IV) binary solution without PEG; resistivity (ρ) was 2.12 × 10−3 Ω·cm, and the calculated power factor (PF) was 5.3 μW·cm−1K−2 and 4.07 times that without PEG.

Oral Administration of Copper Chloride Damages DNA, Lowers Antioxidant Defense, Alters Metabolic Status, and Inhibits Membrane Bound Enzymes in Rat Kidney.

Copper (Cu) is a heavy metal that is widely used in industries and is also an essential micronutrient for living beings. However, excess Cu is toxic and human exposure to high levels of this metal results in numerous adverse health effects. We have investigated the effect of oral administration of copper chloride (CuCl2), a Cu(II) compound, on various parameters of oxidative stress, cellular metabolism, and DNA integrity in the rat kidney. This was done to delineate the molecular mechanism of Cu(II) toxicity. Adult male rats were randomly divided into five groups. Animals in four CuCl2-treated groups were separately administered single acute oral dose of CuCl2 at 5, 15, 30, and 40mg/kg body weight. Animals in the fifth group were not given CuCl2 and served as the control. All rats were sacrificed 24h after the dose of CuCl2 and their kidneys removed. CuCl2 administration led to significant alterations in enzymatic and non-enzymatic parameters of oxidative stress. It changed the activities of metabolic and membrane bound enzymes and also decreased the activities of brush border membrane enzymes. CuCl2 treatment dose-dependently enhanced DNA damage and DNA-protein crosslinking in renal cells, when compared to the control group. The administration of CuCl2 also resulted in marked morphological changes in the kidney, with more prominent alterations at higher doses of CuCl2. These results clearly show that CuCl2 impairs the antioxidant defense system resulting in oxidative damage to the kidney.

Effects of cooling rate on the microstructure control and liquid–liquid phase separation behavior of Cu–Fe–P immiscible alloys

In this article, the influences of cooling rate on the microstructure evolution and liquid–liquid phase separation behavior of Cu–16.2Fe–4.5 P immiscible alloys were systematically investigated. With the cooling rate changing from 1580 K/s to 30 K/s, Cu–16.2Fe–4.5 P metallic samples were still composed of Cu, Fe2P, Fe3P and Cu3P phases according to XRD analyses. With the cooling rate as 1580 K/s, it was observed that Fe–P particles as secondary phase exhibited nearly spherical shape with a uniform dispersion in Cu-rich matrix, which was attributed to the suppressed Marangoni convection and Stokes motion. As the cooling rate decreasing to 30 K/s, an evolving core-shell structure in this alloy was observed to be formed due to the relatively sufficient liquid separation occurrence. Furthermore, it was found that a Fe2P layer was formed to be encapsulated secondary phase, in which Fe3P and Cu particles were also examined. In addition, the microstructure evolution mechanism of Cu–16.2Fe–4.5 P alloys with different cooling rate was also applied.

Synthesis, crystal structures and anti-cancer mechanism of Cu(II) complex derived from 2-acetylpyrazine thiosemicarbazone

Anti-cancer activity of 2-acetylpyrazinethiourea derivatives against NCI-H460, A549, HepG2 and HeLa cell lines was evaluated, with IC50 values ranging from 2.64 to 19.43 µM, among which N,N-diethyl-2-(1-(pyrazin-2-yl)ethylidene)hydrazinecarbothioamide (L4) showed the highest anti-cancer activity (IC50 = 2.64 ± 0.15 µM). L4 reacted with copper bromide, and consequently, Cu(II)-N,N-diethyl-2-(1-(pyrazin-2-yl)ethylidene)hydrazinecarbothioamide (4a) was formed and isolated. This complex was characterized by single crystal X-ray diffraction, elemental analysis, and infrared spectroscopy. L4 is a tridentate ligand that forms a new mononuclear complex with Cu(II). X-Ray diffraction of single crystals showed that 4a crystallizes in the triclinic crystal system in the P-1 space group. The anti-lung cancer (A549) activity of 4a (IC50 = 0.35 ± 0.02 µM) was increased sevenfold compared with that of L4. The detection of anti-cancer mechanisms suggested that the cytotoxicity of 4a is due to its promotion of apoptosis of A549 cells and inhibition of cell cycle. The mechanism by which 4a promotes apoptosis involves a high level of reactive oxygen species, which causes a decrease in the mitochondrial membrane potential and the cleavage of caspase-7 and caspase-9.

RAIRS Characterization of CO and O Coadsorption on Cu(111).

In a study preliminary to investigating CO2 dissociation, we report our results on oxygen and carbon monoxide coadsorption on Cu(111). We use reflection adsorption infrared spectroscopy and Auger electron spectroscopy to characterize and quantify adsorbed species. On clean Cu(111), the CO internal stretch mode appears initially at 2077 cm–1 for a surface temperature of ∼80 K. We accurately reproduce the previously determined redshift of the absorption band with increasing CO coverage. We subsequently oxidize the surface by exposure to O2 at 300 K to ensure O2 dissociation. The band’s frequency and line shape of subsequently adsorbed CO at ∼80 K are not affected. However, the maximum absorbance and integrated peak intensities drop with increasing O coverage. The data suggest that CO is not adsorbed near O, likely as a consequence of the mechanism of Cu(111) surface oxidation by O2 at 300 K. We discuss whether our RAIRS results may be used to quantify CO2 dissociation in the zero-coverage limit.

Fabrication of nitrogen-doped graphene quantum dots hybrid membranes and its sorption for Cu(II), Co(II) and Pb(II) in mixed polymetallic solution

With the rapid development of new–energy batteries, heavy-metals pollution from spent batteries has drawn much attention. Various techniques are recently proposed to delete or eliminate such pollution. Among which, membrane sorption exhibits exceptional advantages for the separation of multi-metal solution. For such a purpose, nitrogen-doped graphene quantum dots (N-GQDs) hybrid membranes were fabricated via sol–gel technique and hydrothermal synthesis, in which the precursor powder of N-GQDs was obtained by the combination of urea (used as a nitrogen source) and citric acid (used as a carbon source). Subsequently, the N-GQDs precursor was mixed with silane and PVA to generate N-GQDs hybrid membranes (NHMs). Competitive sorption of Cu(II), Co(II) and Pb(II) in the mixed polymetallic solution, such as a mixed Cu(II), Co(II) and Pb(II) ternary solution, a mixed Cu(II), Pb(II), Ca(II), Co(II) and Cr(III) quintuple solution, was investigated. It indicated that Cu(II) sorption on NHMs had better selectivity in these mixed polymetallic solutions. Moreover, sorption mechanism of Cu(II), Co(II) and Pb(II) demonstrates that the sorption of NHMs for Cu(II) and Pb(II) abided by Elovich model, indicating the properties of heterogeneous chemisorption. Such a trend shows that the sorption via chemical process between the active sites on the top-layer of NHMs, and Cu(II) and Pb(II) is one of the dominant interfering factors. Desorption testing demonstrated that EDTA-2Na is a best de-sorbent for Cu(II) sorption on NHMs and the number of cycles of these membranes can reach up to 10 times. These findings suggest that NHMs can be used to adsorb Cu(II), Co(II) and Pb(II) from mixed polymetallic solution, indicating promising applications in the successive separation of wastewater containing multiple mixed toxic metals from spent new-energy batteries and other metal-containing wastewater.

Aging process and strengthening mechanism of Cu–Cr–Ni alloy with superior stress relaxation resistance

With the development trend of connectors to high-current and high-temperature service, copper alloy connectors are required to have superior stress relaxation resistance. In this work, the optimal aging parameter was explored via stress relaxation resistance, strength, microhardness, and conductivity. And the strengthening mechanism of stress relaxation was investigated through the TEM and EBSD microscopic characterization. The results show that the Cu–Cr–Ni alloy reached the peak aging state under 450 °C for 1 h and obtained excellent properties. Especially, the percentage of residual stress in the relaxation test reached 93.1%. The microhardness associated with aging strengthening showed a positive correlation with yield strength and stress relaxation resistance. Then the microhardness after aging can be used as a simple evaluation index of stress relaxation resistance. The Cu–Cr–Ni alloy with superior stress relaxation resistance is mainly related to dislocation strengthening, second phase strengthening, and the coexistence of spinodal decomposition and ordering.

Effects of cross-sectional area and aspect ratio coupled with orientation on mechanical properties and deformation behavior of Cu nanowires

Metal nanomaterials exhibit excellent mechanical properties compared with corresponding bulk materials and have potential applications in various areas. Despite a number of studies of the size effect on Cu nanowires mechanical properties with square cross-sectional, investigations of them in rectangular cross-sectional with various sizes at constant volume are rare, and lack of multifactor coupling effect on mechanical properties and quantitative investigation. In this work, the dependence of mechanical properties and deformation mechanisms of Cu nanowires/nanoplates under tension on cross-sessional area, aspect ratio of cross-sectional coupled with orientation were investigated using molecular dynamics simulations and the semi-empirical expressions related to mechanical properties were proposed. The simulation results show that the Young’s modulus and the yield stress sharply increase with the aspect ratio except for the 〈110〉{110}{001} Cu nanowires/nanoplates at the same cross-sectional area. And the Young’s modulus increases while the yield stress decreases with the cross-sectional area of Cu nanowires. However, both of them increase with the cross-sectional area of Cu nanoplates. Besides, the Young’s modulus increases with the cross-sectional area at all the orientations. The yield stress shows a mildly downward trend except for the 〈111〉 Cu nanowires with increased cross-sectional area. For the Cu nanowires with a small cross-sectional area, the surface force increases with the aspect ratio. In contrast, it decreases with the aspect ratio increase at a large cross-sectional area. At the cross-sectional area of 13.068 nm2, the surface force decreases with the aspect ratio of the 〈110〉 Cu nanowires while it increases at other orientations. The surface force is a linearly decreasing function of the cross-sectional area at different orientations. Quantitative studies show that Young’s modulus and yield stress to the aspect ratio of the Cu nanowires satisfy exponent relationship. In addition, the main deformation mechanism of Cu nanowires is the nucleation and propagation of partial dislocations while it is the twinning-dominated reorientation for Cu nanoplates.

Catalyst-enhanced micro-galvanic effect of Cu3N/Cu-bearing NiTi alloy surface for selective bacteria killing

NiTi alloy stent is widely applied to the treatment of coronary artery disease, however, stent associated bacterial infection may occur because of its lack of antibacterial ability. Endowing the selective antibacterial ability is promising for NiTi alloy but still remains a considerable challenge. Here, a novel NiTi alloy surface embedded with cuprous nitride/copper nanoparticles (Cu3N/Cu NPs) was constructed by sequential Cu and N plasma immersion ion implantation & deposition (PIII&D). First, the Cu atoms evenly nucleated and grew into Cu nanoparticles on the NiTi alloy surface during Cu PIII&D process followed by partially transforming to Cu3N by N PIII&D treatment. Due to the electrocatalysis of Cu3N, Cu and N PIII&D modified NiTi alloy surface demonstrated a catalyst-enhanced micro-galvanic effect, which produced excellent antibacterial abilities against both Gram-negative and positive bacteria. The antibacterial mechanism of Cu and N PIII&D NiTi alloy surface was verified to primarily correlate with the blocked ATP synthesis and oxidative stress of bacteria due to the overconsumption of protons and the production of reactive oxygen species (ROS) by continuous catalyst-enhanced micro-galvanic reaction. Meanwhile, this modified NiTi alloy surface showed an enhancement effect on the adhesion and proliferation of human umbilical vein endothelial cell. This study provides a new sight for how to endow implant with selective antibacterial ability.

MXene-mediated electron transfer in Cu(II)/PMS process: From Cu(III) to Cu(I)

There exists an obvious contradiction between Cu(III) generation and Cu(I) contribution in reductants enhanced Cu(II)/peroxymonosulfate (PMS) process because the involved electron transfer pathways were always ignored in previous studies. This study investigated the MXene-mediated electron transfer mechanism in Cu(II)/PMS for the first time. The introduction of MXene significantly promoted atrazine degradation under acidic condition because the in-situ generation of Cu(I) was an excellent activator for PMS. Under alkaline condition, although addition of MXene generated a large amount of Cu(I), the degradation of atrazine was inhibited due to that the conversion of Cu(I) to Cu(III) was interrupted. The strong metal-support interaction (SMSI) altered the reactive intermediate species from Cu(III) (two-electron transfer) to hydroxyl radical (HO•) and sulfate radical (SO4•-) (one-electron transfer) under alkaline condition. This work proposed a novel MXene-mediated electron transfer mechanism and improved the understanding of Cu(III)/Cu(I) transformation pathway.

Remediation of Cu and As contaminated water and soil utilizing biochar supported layered double hydroxide: Mechanisms and soil environment altering

Preparing materials for simultaneous remediation of anionic and cationic heavy metals contamination has always been the focus of research. Herein a biochar supported FeMnMg layered double hydroxide (LDH) composites (LB) for simultaneous remediation of copper and arsenic contamination in water and soil has been assembled by a facile co-precipitation approach. Both adsorption isotherm and kinetics studies of heavy metals removal by LB were applied to look into the adsorption performance of adsorbents in water. Moreover, the adsorption mechanisms of Cu and As by LB were investigated, showing that Cu in aqueous solution was removed by the isomorphic substitution, precipitation and electrostatic adsorption while As was removed by complexation. In addition, the availability of Cu and As in the soil incubation experiments was reduced by 35.54%–63.00% and 8.39%–29.04%, respectively by using LB. Meanwhile, the addition of LB increased the activities of urease and sucrase by 93.78%–374.35% and 84.35%–520.04%, respectively, of which 1% of the dosage was the best. A phenomenon was found that the richness and structure of microbial community became vigorous within 1% dosage of LB, which indirectly enhanced the passivation and stabilization of heavy metals. These results indicated that the soil environment was significantly improved by LB. This research demonstrates that LB would be an imaginably forceful material for the remediation of anionic and cationic heavy metals in contaminated water and soil.

Dislocation evolution in copper in the absence and presence of hydrogen

In the absence and presence of hydrogen, the change of dislocation structure as increasing strain in a coarse-grained polycrystalline Cu was compared. By classifying dislocation structure with crystallographic orientation, it was found that hydrogen has almost no effect on the tensile property and dislocation evolution in coarse-grained Cu. Density functional calculation was used to reveal the underlying dislocation-H interaction mechanism in Cu. The electron structure interaction between Cu and H was the main factor that inhibited the hydrogen accumulation around dislocation, and it was attributed as the principal reason for high resistance to hydrogen embrittlement of coarse-grained Cu.