查找使用阿拉丁产品的科研文献

Understanding the self-catalyzed decomplexation mechanism of Cu-EDTA in Ti3C2Tx MXene/peroxymonosulfate process

Daoyuan Zu,Haoran Song,Changping Li,Yuwei Wang,Rong Du,Rui Zhou,Wei Zhang,Shiting Pan,Yang Cai,Yongming Shen,Zhifeng Yang

Self-catalyzed decomplexation of Cu-ethylene diamine tetraacetic acid complex (Cu-EDTA) and recovery of Cu without addition of extraneous transition metals were achieved in Ti 3 C 2 T x MXene/peroxymonosulfate (Ti 3 C 2 T x /PMS) process. Free radical quenching experiments and electron spin resonance (ESR) measurements demonstrated that both hydroxyl radical (HO • ) and sulfate radical (SO 4 •- ) contributed to the degradation of Cu-EDTA. Activation of PMS by Ti 3 C 2 T x initiated Cu-EDTA decomplexation and released free Cu ions . Then, the formation of Ti-O-Cu bonds between Cu ions and Ti 3 C 2 T x accelerated the electron transfer from Ti 3 C 2 T x to Cu(Ⅱ) and triggered Cu(Ⅱ)/Cu(Ⅰ) cycle, which further enhanced PMS activation and led to the self-catalyzed decomplexation of Cu-EDTA. Simultaneous recovery of Cu was achieved due to the excellent absorption performance of negative charged Ti 3 C 2 T x towards Cu ions. This study revealed the self-catalyzed decomplexation mechanism of Cu-EDTA in the Ti 3 C 2 T x /PMS process and provided a feasible strategy for heavy metal complexes treatment.

Boosting Hydrogen Evolution through the Interface Effects of Amorphous NiMoO4–MoO2 and Crystalline Cu

Yue Yao,Enlai Hu,Zhiyu Wang,Yuanjing Cui,Guodong Qian

The rational design and synthesis of a highly efficient and cost-effective electrocatalyst for hydrogen evolution reaction (HER) are of great importance for the efficient generation of sustainable energy. Herein, amorphous/crystalline heterophase Ni–Mo–O/Cu (denoted as a/c Ni–Mo–O/Cu) was synthesized by a one-pot electrodeposition method. Thanks to the introduction of metallic Cu and the formation of amorphous Ni–Mo–O, the prepared electrocatalyst exhibits favorable conductivity and abundant active sites, which are favorable to the HER progress. Moreover, the interfaces consisting of Cu and Ni–Mo–O show electron transfers between these components, which might modify the absorption/desorption energy of H atoms, thus accelerating HER activity. As expected, the prepared a/c Ni–Mo–O/Cu possesses excellent HER performance, which affords an ultralow overpotential of 34.8 mV at 10 mA cm–2, comparable to that of 20 wt % Pt/C (35.0 mV), and remarkable stability under alkaline conditions.

Carbon sequestration during Fe(III)-Fulvic acid coprecipitation and kinetics of hydrated Cu(II)

Yihao Li,Hongmei Tang,Xiangqin Peng,Shiyang Tao,Jie Ding,Meiqing Chen,Pingxiao Wu,Nengwu Zhu

The dynamic interactions among iron (Fe) oxides and organic matter (OM) play vital roles in controlling the geochemical cycling of carbon (C) and toxic trace metals. Although the effects of OM on the Fe oxides transformation, and dynamic with toxic trace metals have been studied previously, it is still poor to understand the mechanistic and quantitative on the C sequestration during the Fe(III) mineralization process, and kinetics with hydrated Cu(II) in the acid drainage. In this study, Mössbauer spectroscopy, X-ray absorption spectroscopy (XAS), high resolution transmission electron microscopy (HRTEM), and density functional theory (DFT) were used to elucidate the underlying mechanism for the fine structure of iron minerals, fulvic acid (FA) sequestration and hydrated Cu(II) coordination on Fe oxides. FA dosages played an essential role in the formation of Fe oxides, which can inhibit the formation of Fe-O octahedrons and benefit to the Fe-O tetrahedron. FA molecules were mainly sequestrated on the surfaces of Fe oxides and van der Waals forces were the main interaction between FA and Fe oxides. The hydrated Cu(II) oxides mainly distributed on the surface of iron oxides as divalent oxidation states, and feasible coordinated with phenolic hydroxyl group of FA and Fe oxides. The knowledge of the dynamic coupling between Fe oxide transformation under the effect of FA and the fate of hydrated Cu(II) on Fe oxides provided the basis for predicting the geochemical process of Fe, C and toxic trace metals.

Fabrication and Sintering Behavior of Nano Cu–Ag Composite Paste for High-Power Device

Weishan Lv,Jiaxin Liu,Yun Mou,Yongjie Ding,Mingxiang Chen,Fulong Zhu

Direct synthesis of Cu-containing Beta zeolite without template for selective oxidation of cyclohexane

Zhang Wei,Xue Haonan,Wang Min,Wu Zeying,Ding Linlin,Deng Yaoyao,Wang Wei,Wei Xuejiao,Zhang Zhenwei,Xiang Mei

Cu-containing Beta zeolites (Cu-Beta) are straightforwardly synthesized in a one-pot method without template, where the crucial step is the co-hydrolysis/condensation of silica source and copper salt at the moderate acidic condition. In the solvent-free oxidation of cyclohexane with molecular oxygen (O 2 ), the best cyclohexane conversion result (9.7%) with a KA-oil (cyclohexanone and cyclohexanol) selectivity of 94.1% is obtained over Cu-Beta(100). Structure—activity relationship analysis indicates that the isolated tetrahedral framework Cu 2+ species and chemisorption oxygen species in high concentration on the catalyst surface enhannce the catalic performance. In addition, the catalyst can be easily separated and still remain stable after recycling five times, providing new insights into catalysts design for the catalytic oxidation of cyclohexane to KA-oil.

Superhydrophilic/underwater superaerophobic self-supporting CuS/Cu foam electrode for efficient oxygen evolution reaction

Ya-li Yao,Jin-mei He,Xin Yang,Lei Peng,Xue-dan Zhu,Kan-she Li,Meng-nan Qu

Hydrogen production by electrochemical overall water splitting is an economic and green approach to resolve the looming energy and environmental crisis. However, the electrocatalytic oxygen evolution reaction (OER) generally occurs at low rate due to the delayed reaction kinetics of four-electron transfer. Herein, a kind of crater-like micro-nano structure CuS three-dimensional electrode that was supported on a Cu foam was prepared and used as an electrode anode for overall water splitting. The superhydrophilic/underwater superaerophobic structure can significantly reduce the bubble adhesion on the electrode surface and improve the OER performance. The CuS/CF electrode showed good wettability and superaerophobicity with an underwater contact angle of 153.5°. The CuS/CF (CuS/Cu foam) electrode has been proved to have excellent electrocatalytic activity for water decomposition. In 1.0 M KOH solution, the OER overpotential is 350 mV at 10 mA cm −2 and the Tafel slope is 83 mV dec −1 . In acidic medium of 0.5 M H 2 SO 4 solution, the overpotential of hydrogen evolution (HER) is 134 mV at 10 mA cm −2 and the Tafel slope is 114 mV dec −1 . The underwater superaerophobic electrode still has strong stability after 10 h test. This work provides a new potential electrochemical catalyzed approach to water decomposition by constructing a super-infiltration electrode.

MOF-derived electrochemical catalyst Cu–N/C for the enhancement of amperometric oxygen detection

Wenyan Yin,Milin Zhang,Jingyuan Liu,Khaled Tawfik Alali,Jing Yu,Jiahui Zhu,Peili Liu,Rumin Li,Jun Wang

Electrochemical sensors using ionic liquids as electrolytes for oxygen detection are now getting more and more attention. Recently, an ionic liquid combined with an electrochemically active catalyst system has become popular for boosting the sensing performance of oxygen sensors. In this work, the imidazolyl-based ionic liquid 1-butyl-2,3-dimethylimidazole bis((trifluoromethyl)sulfonyl)imide [Bmmim][TFSI] is first prepared by a facile two-step method. Subsequently, a transition metal and N-codoped porous carbon oxygen reduction electrochemical catalyst Cu–N/C is synthesized by calcining the Cu-doped ZIF-8 precursor and then blending it in different ratios with the ionic liquid [Bmmim][TFSI] as composite electrolytes for oxygen detection. The composite electrolyte Cu–N/C/[Bmmim][TFSI] exhibits increased responses in cyclic voltammetry (CV) and chronoamperometry (CA) relative to that of the pure ionic liquid. Furthermore, the CV and CA data show that 6% Cu–N/C/[Bmmim][TFSI] has the optimum oxygen sensing response with an enhanced reduction peak current, a sensitivity of 0.1678 μA/[% O2] and a good linear fitting coefficient of 0.9991. In conclusion, the results confirm the success of using Cu–N/C as an electrochemical catalyst composed of the Cu–N/C/[Bmmim][TFSI] electrolyte for improving the responsivity, stability and sensitivity towards a wide range of oxygen concentrations.

Pd-Cu nanoalloy for dual stimuli-responsive chemo-photothermal therapy against pathogenic biofilm bacteria

Zefeng Wang,Yanling Peng,Yan Zhou,Shengnan Zhang,Jianxi Tan,Huan Li,Dinggeng He,Le Deng

Photothermal therapy (PTT) is a promising strategy for antimicrobial therapy. However, the application of PTT to treat bacterial infections remains a challenge as the high temperature required for bacterial elimination can partly damage healthy tissues. Selecting the appropriate treatment temperature is therefore a key factor for PTT. In this work, we designed a near-infrared/pH dual stimuli-responsive activated procedural antibacterial system based on zeolitic imidazolate framework-8 (ZIF-8), which was bottom-up synthesized and utilized to encapsulate both Pd-Cu nanoalloy (PC) and the antibiotic amoxicillin (AMO). This procedural antibacterial therapy comprises chemotherapy (CT) and PTT. The former disrupts the bacterial cell wall by releasing AMO in an acidic environment, which depends on the sensitive response of ZIF-8 to pH value change. With the progression in time, the AMO release rate decreased gradually. The latter can then significantly stimulate drug release and further complete the antibacterial effect. This impactful attack consisted of two waves that constitute the procedural therapy for bacterial infection. Accordingly, the treatment temperature required for antibacterial therapy can be significantly lowered under this mode of treatment. This antibacterial system has a significant therapeutic effect on planktonic bacteria (G + /G − ) and their biofilms and also has good biocompatibility; thus, it provides a promising strategy to develop an effective and safe treatment against bacterial infections. Statement of Significance We have developed a near infrared/pH dual stimuli-responsive activated procedural antibacterial system that combines enhanced antibiotic delivery with photothermal therapy and has highly efficient antimicrobial activity . The antibacterial effect of this therapy was based on two mechanisms of action: chemotherapy, in which the bacterial cell wall was first destroyed, followed by photothermal therapy. After exposure to irradiation with an 808 nm laser, the inhibition rates were 99.8% and 99.1% for Staphylococcus aureus and Pseudomonas aeruginosa , respectively, and the clearance rates for their established biofilms were 75.3% and 74.8%, respectively. Thus, this procedural antibacterial therapy has shown great potentiality for use in the photothermal therapy of bacterial infectious diseases, including biofilm elimination.

Effective construction of Cu, S-CQDs/BiVO4 composites through a facile and efficient route

Huadong Liu,Hao Sun,Du Ke Zhen,Cheng Jing liang,Sun XiaoYu

Monoclinic bismuth vanadate (m-BiVO 4 ) is a well-known photocatalytic material. However, its poor charge transport and photogenerated electron hole rapid recombination limit the application of m-BiVO 4 . In this paper, we successfully constructed a novel copper-sulfur co-doped carbon quantum dots (Cu, S-CQDs)/BiVO 4 nanocomposite through a facile and efficient route, which significantly improved the photocatalytic performance of BiVO 4 . The physicochemical properties of Cu, S-CQDs and Cu, S-CQDs/BiVO 4 samples were studied by various characterization. It was concluded from the degradation experiments that the photocatalytic degradation rate of rhodamine B reaches 99% in 60 min under natural light. The degradation curve compounds the quasi-primary kinetic model, and the kinetic coefficient of degradation is 0.07831 min −1 , which is 5.37 times than that of pure BiVO 4 . Moreover, the free radical scavenging experiments reveal that the hole and superoxide radicals play a major role in the photocatalysis process. After four cycles, the activity of photocatalyst exhibits high stability, which is extremely important for the photocatalytic process. In the summery, the prepared Cu, S-CQDs/BiVO 4 has many advantages, such as environmental-friendly, low cost and a wide range of applications.

Photocatalytic Degradation of Gaseous Benzene Using Cu/Fe-Doped TiO2 Nanocatalysts under Visible Light

Tao Tian,Jie Zhang,Lijiang Tian,Sijie Ge,Zhenyu Zhai

Visible-light-enhanced TiO2nanocatalysts doped with Cu and Fe were synthesized using the sol–gel method to investigate their performance in degrading gaseous benzene. The structure and morphology of mono- and co-doped TiO2(i.e., Cu/Fe-TiO2, Cu-Fe-TiO2) were characterized using SEM, EDS, XRD, BET, Raman, UV-vis-DRS, and XPS techniques. The results indicated that the presence of Cu/Fe mono- and co-doped TiO2leads to the formation of an anatase phase similar to pure TiO2. Furthermore, the introduction of Cu/Fe enhanced the presence of lattice defects and increased the specific surface area of TiO2. This enhancement can be attributed to the increase in oxygen vacancies, especially in the case of Cu-Fe-TiO2. Additionally, Cu-Fe-TiO2showed a higher concentration of surface-bound hydroxyl groups/chemically adsorbed oxygen and a narrower bandgap than pure TiO2. Consequently, Cu-Fe-TiO2exhibited the highest photocatalytic performance of 658.33 μgC6H6/(g·h), achieving a benzene degradation rate of 88.87%, surpassing that of pure TiO2(5.09%), Cu-TiO2(66.92%), and Fe-TiO2(59.99%). Reusability tests demonstrated that Cu-Fe-TiO2maintained a high benzene degradation efficiency of 71.4%, even after five experimental cycles, highlighting its exceptional stability and reusability. In summary, the addition of Cu/Fe to TiO2enhances its ability to degrade gaseous benzene by prolonging the catalyst’s lifespan and expanding its photoresponse range to include visible light.

Stabilizing Cu+ Species in Cu2O/CuO Catalyst via Carbon Intermediate Confinement for Selective CO2RR

Haojun Shi,Lingli Luo,Congcong Li,Yu Li,Tingting Zhang,Zhongliang Liu,Jialin Cui,Li Gu,Ling Zhang,Yanjie Hu,Huihui Li,Chunzhong Li

Copper oxide nanomaterials have been suggested to be efficient for highly selective multi-carbon (C 2+ ) production in CO 2 reduction reaction (CO 2 RR), due to the introduction of surface Cu + species from oxide catalysts. However, the Cu + species on the catalyst surface are prone to being reduced to Cu 0 under reductive conditions during CO 2 RR. Here, a network-structured catalyst is developed consisting of ultrafine Cu 2 O/CuO nanoparticles that harbor an abundance of pores. This catalyst is synthesized via flame spray pyrolysis (FSP) method and engineered to confine carbon intermediates, which subsequently cover the local catalyst surface and stabilize Cu + species. As a result, a C 2+ products Faradaic efficiency (FE) of approximately 80.0% at a partial current density of 320.0 mA cm −2 is achieved, and a large C 2+ to C 1 ratio of ≈9.7. In situ XRD and XPS spectra are employed to reveal the indeed presence of Cu + species on the catalyst surface during the CO 2 RR process, which extensively improves the adsorption of * CO intermediates and thus the C─C coupling reaction to form C 2+ products.

Point-of-need electrochemical detection of Cu²⁺ via target-accelerated growth of gold nanoparticles

Hancong Du,Jiarui Li,Fengling Tian,Wenli Zhu,Kaxi Chen,Mengxia Li,Shan Liao,Yali Yuan,Jinfang Nie,Yun Zhang

A point-of-care sensor was initially reported for portable detection of Cu 2+ ions. • It was based on the Cu 2+ -accelerated growth of gold nanoparticles. • These nanoparticles could enhance the conductivity of screen-printed electrodes. • Only a hand-held electrochemical reader was required to achieve a detection limit down to ∼1.6 nM. This paper initially reports an electrochemical method for point-of-care sensing of divalent copper (Cu 2+ ) ions by combining screen-printed electrodes (SPEs) with a hand-held current reader. In the buffer of 4-morpholineethanesulfonic acid, chloroauric acid can be slowly reduced into gold nanoparticles (GNPs). In the presence of Cu 2+ , the analyte is able to significantly promote the growth process of GNPs. These GNPs generated in the reaction solution then act as efficient electronic nanoconductors to greatly enhance the SPE’s conductivity leading to an enhanced current response. The enhancement degree of this current signal is positively proportional to Cu 2+ concentration in the sample. The results indicate that this new electrochemical method only requires disposable SPEs without functional modification and a user-friendly, portable current reader to linearly detect Cu 2+ in a concentration range of 24.41 - 6250 nM. Its detection limit is estimated to be about 1.6 nM (3σ rule), which is far lower than the maximum allowable concentrations in drinking water stipulated by the World Health Organization (∼30 µM) and the National Health Commission of China (∼15 µM). The acceptable recovery of Cu 2+ in several real water samples (i.e., drinking water, tap water and pond water) is between 98.03 and 106.95%. Download: Download high-res image (118KB) Download: Download full-size image