查找使用阿拉丁产品的科研文献

Photocatalytically Active Semiconductor Cu3P Unites with Flocculent TiN for Efficient Removal of Sulfamethoxazole

Huancong Shi,Xulei Yao,Shijian Lu,Yuanhui Zuo,Tao Zheng,Liangquan Jia

Sulfamethoxazole is a widely—used antibiotic with high water solubility and low biodegradability, which was considered a refractory environmental pollutant. Hence, a series of functionalized hybrids uniting Cu3P with TiN were prepared. The Cu3P/TiN—x composites remarkably removed the sulfamethoxazole in solution compared with Cu3P and TiN alone. All the as—prepared Cu3P/TiN—x hybrids integrated the advantages of strong adsorption and photocatalysis and achieved removal rates above 70% of sulfamethoxazole. Among the composites, the Cu3P/TiN—2 with a 1:1 molar ratio of Cu: Ti reached a 90% removal rate under dark adsorption for 30 min and subsequent photodegradation for 120 min. The enhanced performance of the Cu3P/TiN—x composites is attributed to the introduced flocculent TiN with a large specific surface area and high conductivity that provide more reactive sites and high electron transferability. Meanwhile, the strong corrosion resistance and chemical stability were also beneficial to the improved performance. Cycling experiments further demonstrate the stability and reliability of the composites. In addition, the capture experiments indicated that the superoxide radical (·O2−) and hydroxyl radical (·OH) played a major role in sulfamethoxazole degradation.Keywords:Cu3P/TiN;plasmonic photocatalyst;sulfamethoxazole;photodegradation

Synthesis of N-(2-ethylhexyl)-pyridine-4-carboxamide and its synergistic behaviors with dinonylnaphthalene sulfonic acid for the selective extraction of nickel and cobalt

Wensen Liu,Hui Su,Jian Zhang,Lina Wang,Yahui Liu,Jie Liang,Zhaowu Zhu

The hydrometallurgical process for the recovery of nickel and cobalt requires a complex and expensive impurity removal process. Solvent extraction is widely used in industry for the separation, purification, and concentration of metals. However, current commercial extractants encounter some difficulties when cobalt and nickel are extracted from solutions containing a large amount of impurities such as manganese and calcium. There is an urgent need to develop new reagents for the selective extraction of Ni and Co. In this study, N-(2-ethylhexyl)-pyridine-4-carboxamide (NEHPCA) was synthesized, and the metal extraction capacity of its synergistic solvent extraction (SSX) system with dinonylnaphthalene sulfonic acid (DNNSA) and tributyl phosphate (TBP) modifier was examined. The experimental results show that the selectivity of the new SSX system has the order Cu > Ni > Co > Zn > Mn > Ca > Al ≈ Cr (III) ≈ Mg ≈ Fe (III), with excellent selectivity for nickel and cobalt. Using an organic phase composed of 0.7 M NEHPCA, 0.35 M DNNSA, and 0.2 M TBP under 1:1O/A operation, after three-stage theoretical extraction, more than 99% of nickel and cobalt can be recovered from a synthetic leaching solution of nickel laterite ore. Mechanistic studies showed that NEHPCA and water molecules participate in the internal coordination of metals, and DNNSA provided coordination anions to achieve charge balance, forming the Ni complex in this SSX system which existed most likely in the form of [Ni(NEHPCA) 2 (H 2 O) 4 ](DNNS) 2 in the organic phase.

Approaching the structure-property relationship of sintered metal nano/microparticles from the perspective of the agglomerate size effect

Guannan Yang,Haiqi Lai,Wei Lin,Jing Tong,Zhen Peng,Jun Cao,Jiye Luo,Yu Zhang,Chengqiang Cui

In this study, we explore the structure-property relationship of sintered metal nano/microparticles from the perspective of the agglomerate size effect. Through sintering experiments and mechanical tests of Cu particle pastes with different solvents, a linear correlation between the agglomerate size in the particle paste ( L a ) and the size of large-scale cavities in the sintered structure ( L c ) is revealed, and a negative correlation between the cavity size and the shear strength of the sintered structure is discovered. Based on these results, a quantitative model is proposed to predict the overall strength of the sintered structure ( τ f ). A relationship τ f = τ c /(1 + √(2 L cmax / d )) is established, which fits the experimental results very well. The model reveals that the relative agglomerate size ( L a / d ) or relative cavity size ( L c / d ) plays a more important role than the particle size ( d ) itself in terms of defining the final sintering properties of metal nano/microparticles.

Integration of ultrafine CuO nanoparticles with two-dimensional MOFs for enhanced electrochemical CO2 reduction to ethylene

Linlin Wang,Xin Li,Leiduan Hao,Song Hong,Alex W. Robertson,Zhenyu Sun

To facilitate the electrochemical CO 2 reduction (ECR) to fuels and valuable chemicals, the development of active, low cost, and selective catalysts is crucial. We report a novel ECR catalyst consisting of CuO nanoparticles with sizes ranging from 1.4 to 3.3 nm anchored on Cu metal-organic framework (Cu-MOF) nanosheets obtained through a one-step facile solvothermal method. The nanocomposites provide multiple sites for efficient ambient ECR, delivering an average C 2 H 4 faradaic efficiency (FE) of ~50.0% at –1.1 V (referred to the reversible hydrogen electrode) in 0.1 mol/L aqueous KHCO 3 using a two-compartment cell, in stark contrast to a C 2 H 4 FE of 25.5% and 37.6% over individual CuO and Cu-MOF respectively, also surpassing most newly reported Cu-based materials under similar cathodic voltages. The C 2 H 4 FE remains at over 45.0% even after 10.0 h of successive polarization. Also, a ~7.0 mA cm −2 C 2 H 4 partial geometric current density and 27.7% half-cell C 2 H 4 power conversion efficiency are achieved. The good electrocatalytic performance can be attributed to the interface between CuO and Cu-MOF, with accessible metallic moieties and the unique two-dimensional structure of the Cu-MOF enhancing the adsorption and activation of CO 2 molecules. This finding offers a simple avenue to upgrading CO 2 to value-added hydrocarbons by rational design of MOF-based composites.

Comparative study of the electrocatalytic N2 reduction property of a Cu4 cluster with μ2-/μ3-OH and a Cu2 complex with μ2-OH

Wei Wang,Jing-Zhe Li,Shi-Jian Luo,Zi-Xuan Yao,Kuan-Guan Liu

Using the atomic precisely structurally characterized clusters as electrocatalysts can provide some possible structure information about the active intermediate during the electrocatalytic N 2 reduction reaction (NRR) process. A Cu4 cluster, named [(bpy) 4 Cu 4 (C 10 H 8 SO 3 ) 4 (OH) 4 ]•4H 2 O ( 1 ), has been synthesized and fully characterized by IR, SXRD, XPS, EPR, et al. Single crystal structural analysis reveals that the core structure of the cluster has a step-scheme conformation with two μ 2 -OH and two μ 3 -OH groups. Electro-catalysis studies of this cluster show that it can achieve a highest NH 3 yield of 2.18 μg h −1 mg −1 and a FE of 0.97 % at −0.6 V. The excellent NRR performance may be attributable to the additional μ 3 -OH groups, based on the contrastively study of the other electrocatalysts of the Cu powder and the Cu 2 complex, named [(μ 2 -OH)(μ 2 -Cl)(bpy) 2 Cu 2 Cl 2 ] ( 2 ), with one μ 2 -OH group in its structure. This work provides some structure information about the possible active sites during the NRR process and inspires us to develop new cluster as efficient electrocatalysts for advancing sustainable NH 3 production. Using the atomic precisely structurally characterized clusters as electrocatalysts can provide some possible structure information about the active intermediate during the electrocatalytic N 2 reduction reaction (NRR) process. A Cu4 cluster, named [(bpy) 4 Cu 4 (C 10 H 8 SO 3 ) 4 (OH) 4 ]•4H 2 O ( 1 ), has been synthesized and fully characterized by IR, SXRD, XPS, EPR, et al. Single crystal structural analysis reveals that the core structure of the cluster has a step-scheme conformation with two μ 2 -OH and two μ 3 -OH groups. Electro-catalysis studies of this cluster show that it can achieve a highest NH 3 yield of 2.18 μg h −1 mg −1 and a FE of 0.97 % at −0.6 V. The excellent NRR performance may be attributable to the additional μ 3 -OH groups, based on the contrastively study of the other electrocatalysts of the Cu powder and the Cu 2 complex, named [(μ 2 -OH)(μ 2 -Cl)(bpy) 2 Cu 2 Cl 2 ] ( 2 ), with one μ 2 -OH group in its structure. This work provides some structure information about the possible active sites during the NRR process and inspires us to develop new cluster as efficient electrocatalysts for advancing sustainable NH 3 production.

Leakage Rate Control of Magnetic Powder Seals by Lubricant Coatings on Magnetic Nanoparticles and Flow Field Simulation

Zhenghao Li,Decai Li

Synergistic effects of tungsten coating on the microstructure, thermophysical and mechanical properties of graphite flakes reinforced copper matrix composites

Xiaozhen Wang,Yishi Su,Qiubao Ouyang,Di Zhang

With the rapid development of the miniaturization and high-integration of electronic devices, conventional thermal conductive materials cannot ensure the safety and reliability of the high-power devices in working environments. It is urgent to develop thermal management materials with excellent thermophysical and mechanical properties . In this work, the tungsten-coated graphite flakes (GFs(W)) were prepared by the immersion reduction, and the GFs(W) reinforced copper matrix composites (GFs(W)/Cu composites) were prepared by the vacuum hot-pressing sintering. Based on the microstructure and surface analysis, the W coating obtained at 900 °C and 200 g/L AMT appears the excellent surface structure and interfacial adhesion, which transfer the interfacial bonding from mechanical combination to mechanical-metallurgical synergy between the GFs and Cu. In addition, the volume fraction of W coating has a threshold to improve properties of the GFs(W)/Cu composites, in which the GFs(6 W)/Cu composites show the outstanding comprehensive performance: the in-plane thermal conductivity and flexural strength are 879.0 ± 10.0 Wm −1 K −1 and 166.9 ± 3.4 MPa respectively, which are improved by 22.3% and 356.0%, and the lowest coefficient of thermal expansion is 4.3 ± 0.5 ppmK −1 . To sum up, it provides an effective way to develop novel structural and functional integrated graphite/copper composites for thermal management.

Enhanced Thermoelectric Performance of Cu2Se via Nanostructure and Compositional Gradient

Lin Bo,Fujin Li,Yangbo Hou,Min Zuo,Degang Zhao

Forming co-alloying solid solutions has long been considered as an effective strategy for improving thermoelectric performance. Herein, the dense Cu2−x(MnFeNi)xSe (x= 0–0.09) with intrinsically low thermal conductivity was prepared by a melting-ball milling-hot pressing process. The influences of nanostructure and compositional gradient on the microstructure and thermoelectric properties of Cu2Se were evaluated. It was found that the thermal conductivity decreased from 1.54 Wm−1K−1to 0.64 Wm−1K−1at 300 K via the phonon scattering mechanisms caused by atomic disorder and nano defects. The maximumzTvalue for the Cu1.91(MnFeNi)0.09Se sample was 1.08 at 750 K, which was about 27% higher than that of a pristine sample.Keywords:thermoelectric material;nanostructured;interfacial engineering;multi-scale scattering centers

Brazing of TiAl and Ti2AlNb alloys using high-entropy braze fillers

Z. Sun,X.X. Zhu,H.Z. Chen,L.X. Zhang

To address the excessive formation of brittle compounds when brazing TiAl alloys, a TiZrHfCoNiCu high-entropy brazed filler was developed to realize the brazing of TiAl/Ti 2 AlNb couples. The TiAl/Ti 2 AlNb brazed joints can be divided into 4 zones, i.e., 2 diffusion zones at the TiAl/braze filler, Ti 2 AlNb/braze filler interfaces and 2 zones divided inside the brazed seam. α 2  + γ-TiAl were the main reaction products formed at the TiAl/braze filler interface and α 2 + Ti 0.5 Al 0.12 Nb 0.38 were the main reaction products at the Ti 2 AlNb/braze filler interface. Effects of brazing temperatures on the interfacial microstructure and mechanical properties of the TiAl/Ti 2 AlNb brazed joints were investigated. When brazing at 1100°C/15 min, the highest shear strength can reach 157 MPa (room temperature), and 123 MPa (650°C) respectively. The relationship between the microstructure and the corresponding mechanical response were discussed in detail. This research can offer new insights on developing desirable brazing filler when joining TiAl and TiAl based alloys.

Macro-encapsulated metallic phase change material over 1000 °C for high-temperature thermal storage

Nan Sheng,Yunfei Ge,Yunqi Guo,Chunyu Zhu,Zhonghao Rao

This study reports the successful fabrication of Cu@Al 2 O 3 macro-encapsulated metallic PCMs for high-temperature thermal storage over 1000 °C. Cu powders are employed as raw material which are spherulitized to core balls in millimeter-size, and subsequently the core balls are cladded with Al 2 O 3 ceramic shells. After the low-temperature pre-sintering and subsequent high-temperature sintering treatment, the Cu@Al 2 O 3 macrocapsules which contain gaps between the shells and cores are successfully prepared. The core balls are consisted of Cu powders which are not densified but are porous, offering buffer spaces to accommodate the thermal volume expansion during high-temperature sintering and melting of Cu. As a comparison, Cu@Al 2 O 3 macrocapsules prepared by directly coating the commercial solid Cu balls are leaky. Thermal analysis indicates that the metallic core PCM has a melting temperature of 1063 °C and a latent heat of around 210 J/g. The macrocapsules are also highly durable as confirmed by the melting-solidification cycling test. These results demonstrate that the Cu@Al 2 O 3 macrocapsules are applicable as high-temperature heat storage media, which can find useable applications in advanced high-temperature thermal energy storage systems .

A green slurry electrolysis to recover valuable metals from waste printed circuit board (WPCB) in recyclable pH-neutral ethylene glycol

Kaixin Liu,Shuquan Huang,Yangxin Jin,Lan Ma,Wen-Xiong Wang,Jason Chun-Ho Lam

The continuous growth of e-waste necessitates an efficient method to recover their metal contents to improve their recycling rate. The successful recovery of the metallic component from Waste Electrical and Electronic Equipment (WEEE) can generate great economic benefits to incentivize the industrial recycling effort. In this study, we report the use of slurry electrolysis (SE) in pH-neutral ethylene glycol (EG) electrolyte to extract and recover the metallic component from waste printed circuit broad (WPCB) powder. The system operates at room temperature and atmospheric pressure, and the electrolyte can be recycled multiple times with no signs of chemical degradation . The EG electrolyte system can oxidize the metallic component without triggering anodic gas evolution, which allowed us to incorporate a reticulated vitreous carbon (RVC) foam anode to maximize the capture and oxidation of the metal content. The system demonstrated up to 99.1% Faraday efficiency for the cathodic metal deposition and could recover Cu from the WPCB powder in a selective manner of 59.7% in the presence of 12 other metals. The SE reaction system was also scalable and displayed no compromises on the Cu recovery selectivity . With the ability to leach and recover metallic content from WPCB in a mild and chemically benign condition, the SE system displayed much promise to be adapted for industrial-scale metal recovery from WPCB.

Laser-Engraved Boron-Doped Diamond for Copper Catalyzed Non-Enzymatic Glucose Sensing

Qian Gao,Wangyang Zhang,Chaopeng Zhao,Weishan Yan,Suqin Han,Yanyan Li,Qiao Liu,Xi Li,Duo Liu

Robust and high-performance electrochemical electrodes for non-enzymatic glucose sensing are in constant demand. Herein, a hierarchical nonenzymatic glucose sensing electrode on boron-doped diamond (BDD) is fabricated using high-speed laser engraving and pulsed electrodeposition of Cu nanostructures. The obtained electrode contains a densely packed Cu nanoflake (CuNF) array periodically decorated on the laser-engraved BDD. The hierarchical nanoarchitecture combines the d-band catalytic activity of the CuNFs with the low capacitive background current of the engraved BDD substrate, thus enabling fast, precise, and high signal-to-noise ratio detection of trace glucose. Outstanding performances that combine high sensitivity of 2119 µA cm –2 m m –1 , ultrafast response time of <1 s, and low detection limit of 0.2 × 10 −6 m are experimentally demonstrated. Furthermore, the electrode exhibits excellent cyclicality and anti-interference ability, and maintains 90% of its initial responsivity after being stored in air for >8 months, indicating great stability for practical usage.