Nanoscale
·
2017
·Vol. 9
·期 8
·2824-2835
·
IF 7.367
Zhi-Qiang Zhou,Li-Yun Yang,Ren Yan,Jie Zhao,Yu-Qi Liu,Lu Lai,Feng-Lei Jiang,Thomas Maskow,Yi Liu
Although cation exchange (CE) has been studied for many years and some mechanisms were proposed, there is still a knowledge gap in CE and problems such as the need for high temperature and it being time-consuming are still unaddressed. We developed a new mild strategy for CE by introducing a new ideal template and first applied this doping strategy to detect Cd2+ and Hg2+. This strategy adopted Mn-doped ZnSe quantum dots (QDs) as the template and the introduction occurs via a two-step CE reaction: first Zn2+ was partially substituted by X (X = Cd2+, Hg2+, Cu2+, Ag+ or Pb2+), later Mn2+ (in the deep structure of QDs) was substituted by X. Remarkably, Mn2+ in the lattice can be easily substituted by a dopant and its replacement by a dopant helps to bury the metal ions. The ultra-fast introduction of Cd2+ and Hg2+ (70 minutes for Cd2+ and 19 minutes for Hg2+) was realized at room temperature; other metal ions such as Ag+, Cu2+ and Pb2+ can be buried at 50 °C. This mild reaction temperature offers a solution for introducing impurities without sacrificing the interfacial structure of nanocrystals. HRTEM, XPS and ICP measurements were applied to analyze the introduction process. Furthermore, the spectroscopic method was employed to analyze the introduction, migration and distribution of metal ions. Then, we proposed a mechanism for the chemical conversion of nanocrystals by CE. Through this strategy, full-color light-emitting doped QDs were fabricated. Strikingly, a new turn-on probe for the detection of Cd2+ and Hg2+ with improved selectivity was developed by adopting this doping strategy. The detection limit is 36 nM for Cd2+ and 20 nM for Hg2+, which is competitive with the limit of detection reported by other groups using QDs as sensors.
研究领域:
材料科学
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化学
·
环境科学
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产品关联
DOI
PubMed
高影响因子
FUEL
·
2024
·
IF 6.7
Wenxia Zhang,Hongtao Zhang,Mohamed Abbas,Juan Zhang,Zhijun Huang,Sibudjing Kawi,Jiangang Chen
The advancement of large-scale and environmentally-friendly solid-state synthesis methods is of paramount importance for the production of precipitated catalysts, notably Fe-based catalysts utilized in Fischer-Tropsch synthesis (FTS). In this study, we present an innovative solvent-independent, wastewater-free solid-state approach for the synthesis of highly efficient Fe/ZrO 2 catalysts, elucidating the mechanisms of promotion within this specific methodology. The prepared catalysts underwent rigorous evaluation under industrially-relevant FTS conditions (230–270 °C, 20 bar, and WHSV = 5400 mL/(g cat ⋅h)). A comprehensive suite of characterization techniques was employed to establish the intricate interplay between catalytic activity and structural attributes. We meticulously examined the impact of Na as an alkali promoter and the role of transition metals (Cu and Mn) in enhancing FTS catalytic performance. The catalytic outcomes obtained clearly demonstrate the pivotal role of the synergistic interaction between Mn and Na within the Na-Mn-Fe/ZrO 2 catalyst system in driving the FTS reaction. This synergism significantly enhances FTS performance, yielding an impressive CO conversion rate (89.91 %) while maintaining low selectivity to CH 4 (7.75 %). The incorporation of Mn and Na into the catalyst matrix enhances the dispersion of Fe 2 O 3 , thereby improving the reducibility of Mn/Fe oxides and elevating the electron density on the catalyst surface. These factors facilitate the formation of active Hägg iron carbide (χ-Fe 5 C 2 ), stimulating chain propagation and ultimately leading to the generation of valuable C 5+ hydrocarbon products, which underscores its potential as an optimal candidate for future industrial applications in Fe-based Fischer-Tropsch synthesis.
研究领域:
催化
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化学工程
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环境科学
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材料科学
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产品关联
DOI
高影响因子
CATALYSIS TODAY
·
2024
·
IF 5.2
Xiaoyu Zhang,Xin Xu,Xinyu Wang,Huibin Liu,Mingli Fu
The improvement of catalytic efficiency is of great significance to the removal of volatile organic compounds (VOCs), a class of key air pollutants leading to ground-level ozone pollution. Herein, a series of micro-spherical Ca-Mn mixed oxides (Ca x Mn y O z ), namely CaMn 3 O 6 , Ca 2 Mn 3 O 8 and CaMnO 3 , were prepared by a two-step precipitation method, and defects were constructed on which by selective dissolution to enhance the low-temperature catalytic performance in the oxidation of propane (C 3 H 8 ) as a representative short-chain alkane VOCs. The synthesized Ca x Mn y O z oxides demonstrated drastically different response to the dissolution modification initiated by acid treatment. Specifically, after acid dissolution, while CaMn 3 O 6 and Ca 2 Mn 3 O 8 maintained largely their original structures, the perovskite-type CaMnO 3 underwent lattice rearrangement and was transformed into γ-MnO 2 -like product with only a tiny amount of Ca. In C 3 H 8 oxidation, the catalytic performance of CaMnO 3 was significantly improved after selective dissolution, as indicated by a significant decrease of T 90 , i.e. the temperature to achieve 90% C 3 H 8 conversion, from 455 °C to 240 °C. Mechanistic investigation by in-depth X-ray photoelectron spectroscopy studies revealed that selective dissolution led to higher Mn 4+ concentrations and more oxygen vacancies on the oxide surfaces, thus facilitated electron transfer and O 2 activation in C 3 H 8 oxidation reactions. This study paves a new path for the design of cost-effective oxide catalysts toward the abatement of short-chain alkane VOCs.
研究领域:
催化
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环境科学
·
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2024
·
IF 5.5
Kui Yan,Ruixin Chen,Qi Ling,Ziwei Zhao,Zihan Zhou,Xuan Li,Jianguo Lv,Chunbin Cao,Gang He,Zhaoqi Sun,Miao Zhang
This research presents an innovative approach to the in-situ fabrication of Mn-doped NiFe 2 O 4 (Mn-NiFe 2 O 4 ) nanosheet arrays directly on nickel foam substrates. The formation of precursors on the nickel foam substrates is achieved through spontaneous corrosion, followed by a thermal treatment to form the Mn-NiFe 2 O 4 nanosheet arrays. The material's structure and morphology were thoroughly examined, revealing that the addition of Mn transforms the nanoporous structure on the nickel foam into a nanosheet structure. The average thickness of the nanosheets is 30 nm, and their primary composition is Mn-doped NiFe 2 O 4 . The resulting highly porous structure of these nanosheets provides numerous active sites and effective electron and ion diffusion channels, thereby increasing charge density and mechanical stability. Electrochemical assays show that the areal-specific capacity of the synthesized electrode material reaches 4.34 C cm −2 (areal-specific capacitance is 8.68 F cm −2 ) at 1 mA cm −2 . Notably, the constructed hybrid supercapacitor achieves a power density of 544 µW cm −2 at an energy density of 390 µWh cm −2 . Furthermore, capacitance retention is 95.2% after 5000 charging cycles. Additionally, the assembled device delivers robust and sustained energy output for LED displays and electric toy cars. This method streamlines the production flow of electrode materials, reducing energy consumption while significantly enhancing the areal capacitance of supercapacitors. The assembled hybrid supercapacitor structure diagram and the assembled devices provide power sources for electric toy cars and LED displays.
研究领域:
材料科学
·
电化学
·
纳米技术
·
能源存储
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2025
·
IF 6.3
Hongyu Wang,Tao Wang,Gonghao Li,Bo Wu,Ruijun Gao
Balancing increased recoverable strain with high phase transformation temperature is crucial for Cu-Al-Mn SMAs to cost-effectively overcome the service temperature limitation (<100°C) of NiTi-based SMAs. This study fabricated four types of Cu-12.5Al-3Mn SMAs modified with nano-Al₂O₃ p (0, 0.5, 1.0, and 1.5 wt%) using wire arc additive manufacturing (WAAM) with cored wires. It investigated the effects of nano-Al₂O₃ p on shape memory properties, exploring mechanisms via microstructural, phase, and hardness analysis. Results show that adding an appropriate amount of nano-Al₂O₃ p significantly enhances memory performance while maintaining high martensite transformation temperatures. The 0.5 wt% nano-Al₂O₃ p modified alloy exhibited optimal properties: a shape recovery rate of 87.77 % (13.8 % higher than the base alloy) and a recoverable strain of 7.02 % (>40 % higher than the commonly reported 5 %) under 8 % bending pre-strain. Its Ms temperature remained above 100°C (As, Af, Mf were largely unchanged), and full recovery time was halved compared to the unmodified alloy. The enhancement is attributed to nano-Al₂O₃ p strengthening the parent phase and improving thermoelastic martensite order via pinning. Their high stability under WAAM's high-energy heat source minimizes impact on alloy composition, while dispersed particles create lattice distortion and stress fields, reducing the energy barrier for martensitic transformation.
研究领域:
材料科学
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冶金学
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纳米技术
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机械工程
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产品关联
DOI
高影响因子
Reaction Kinetics Mechanisms and Catalysis
·
2025
·
IF 1.7
Cheng Lijun,Lei Juan,Ren Xiaoli,Chang Hong,Ju Baihe
In this study, a series of La-α-MnO 2 catalysts with different La doping amounts were prepared by hydrothermal method. It was found that the introduction of La could reduce the crystallinity of α-MnO 2 and increase the specific surface area of the catalyst. Furthermore, La doping can significantly weaken the Mn–O bond, increase the surface Mn 3+ and O ads content, and enhance the oxygen mobility and low-temperature reducibility. The catalytic results indicated that La doping could significantly improve the catalytic oxidation performance of toluene, and 1%La-α-MnO 2 catalyst exhibited the best catalytic activity for toluene oxidation. The toluene conversion rate reaches 90% when the reaction temperature is only 215 °C. In addition, 1%La-α-MnO 2 catalyst presented good stability and repeatability during 50 h durability test under water vapor.
研究领域:
催化化学
·
环境科学
·
材料化学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
Asian Journal of Pharmaceutical Sciences
·
2024
·
IF 10.7
Shengnan Huang,Chenyang Zhou,Chengzhi Song,Xiali Zhu,Mingsan Miao,Chunming Li,Shaofeng Duan,Yurong Hu
Postoperative tumor recurrence remains a predominant cause of treatment failure. In this study, we developed an in situ injectable hydrogel, termed MPB-NO@DOX + ATRA gel, which was locally formed within the tumor resection cavity. The MPB-NO@DOX + ATRA gel was fabricated by mixing a thrombin solution, a fibrinogen solution containing all-trans retinoic acid (ATRA), and a Mn/NO-based immune nano-activator termed MPB-NO@DOX. ATRA promoted the differentiation of cancer stem cells, inhibited cancer cell migration, and affected the polarization of tumor-associated macrophages. The outer MnO 2 shell disintegrated due to its reaction with glutathione and hydrogen peroxide in the cytoplasm to release Mn 2+ and produce O 2 , resulting in the release of doxorubicin (DOX). The released DOX entered the nucleus and destroyed DNA, and the fragmented DNA cooperated with Mn 2+ to activate the cGAS-STING pathway and stimulate an anti-tumor immune response. In addition, when MPB-NO@DOX was exposed to 808 nm laser irradiation, the Fe-NO bond was broken to release NO, which downregulated the expression of PD-L1 on the surface of tumor cells and reversed the immunosuppressive tumor microenvironment. In conclusion, the MPB-NO@DOX + ATRA gel exhibited excellent anti-tumor efficacy. The results of this study demonstrated the great potential of in situ injectable hydrogels in preventing postoperative tumor recurrence.
研究领域:
肿瘤学
·
生物材料学
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免疫学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2025
·Vol. 36
·期 14
·831
·
IF 2.8
Zhao Tianqun,Zeng Tianrui,Jin Shilei,Li Xiaohui,Yu Zhiqiang
BNT (BaO–Nd 2 O 3 –TiO 2 ) system was modified via doping using sol–gel method, and BNST-Mn/PTFE microwave dielectric composite was prepared by mechanical blending. Scanning electron microscopy (SEM), thermal dilatometer, and split post-dielectric resonator (SPDR) were used to characterize the microstructure, dielectric properties, and thermal properties of the composite materials. The results indicate that as the amount of ceramic filler supplied grows, the agglomeration of fillers becomes more pronounced. At a filler content of 10 wt%, the dispersion of the filler in the matrix resin is relatively uniform. The dielectric constant and dielectric loss of the composites increased, and the bonding ability between the two phases diminished with the increase in filler content. When the mass fraction of the ceramic was increased to 70 wt%, the dielectric constant of the composite was 10.92 and the Q·f value was measured at 3584 GHz. At the same time, the coefficient of thermal expansion (CTE) of the composites reached 23 ppm/°C, which was a good compatibility with the copper foil. Lichtenecker equation, Maxwell–Wagner equation, Jayasundere–Smith equation, and effective medium theory equation (EMT) were used to predict the dielectric constant of the composites. In comparison, the dielectric constant values calculated using the EMT equation were in good agreement with the experimental values, especially at low filling volumes. Also, the simulation results of the thermal expansion coefficient of composite materials using the Lichtenecker equation and its improved form are in good agreement with the experimental values.
研究领域:
材料科学
·
陶瓷与复合材料
·
介电材料
·
微波技术
✓ 已验证
产品关联
DOI
高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
·
2025
·
IF 7.7
Shiqing Luo,Xiaojie Sun,Lifang Zhang,Yanming Miao,Guiqin Yan
The excessive use of antibiotics has accelerated the rise of antimicrobial resistance (AMR), and rapid antimicrobial susceptibility testing (AST) is very important for the early detection, early prevention and treatment of AMR. On this basis, we combined manganese-doped zinc sulfide quantum dots (Mn-ZnS QDs) with aminated dendritic mesoporous silica nanoparticles (DMSNs-NH 2 ) to prepare Mn-ZnS QDs@DMSNs-NH 2 room-temperature phosphorescent (RTP) nanocomposites. H 2 O 2 can quench the RTP of Mn-ZnS QDs@DMSNs-NH 2 nanocomposites, while catalase-positive bacteria can cause the hydrolysis of H 2 O 2 . Hence, RTP detection of different antibiotic tolerance for Staphylococcus aureus ( S. aureus ) and methicillin-resistant Staphylococcus aureus (MRSA) was achieved. This sensing system can achieve rapid bacterial detection and AST through the difference in RTP intensity. Experimental results demonstrated that the linear detection range for bacteria is 0×10 5 -64×10 5 CFU·mL -1 , with a limit of detection (LOD) of 1×10 5 CFU·mL -1 for MRSA and 0.7×10 5 CFU·mL -1 for S. aureus . The pore confinement effect of DMSNs-NH 2 can induce the aggregation of Mn-ZnS QDs, which strengthens the RTP of Mn-ZnS QDs@DMSNs-NH 2 nanocomposites and improves the sensitivity of RTP detection. This method is not only free from sample background fluorescence interference, but also shortens the AST time (less than 90 min), making antibacterial treatment more time-saving and efficient and reducing patient pains. This nanosensor provides a new strategy for rapid clinical bacterial detection and effective assessment of antimicrobial susceptibility.
研究领域:
材料科学
·
生物医学工程
·
微生物学
✓ 已验证
产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2022
·
IF 9.136
Baicheng Yuan,Xinyi Huang,Shaojinlin Yang,Yi Yang,Zhihong Lin,Raphael Semiat,J. Paul Chen
Heavy metal contamination has become one of the greatest global environmental problems. In this study, a magnetic calcium-alginate hydrogel-sphere encapsulated with Fe–Mn–Zr ternary-metal composite (MCHETC) was prepared through a combined co-precipitation and extrusion approach and used for the adsorption of heavy metals in aqueous solutions. The active sites were dispersed in the MCHETC, which can be separated by the magnetic force for the ease in operation. Above 80% of ultimate adsorption was completed at a contact time of 5 h. The copper uptake history was well described by the intraparticle surface diffusion model, suggesting a multi-step process for the adsorption. The optimum pH for adsorption was 4; the maximum adsorption capacity was 103.1 mg-Cu/g. The adsorption capability well remained after the 5 adsorption–desorption cycles and the copper could be recovered. Furthermore, the adsorbent performed well in the nature water spiked with copper ions. The mechanism studies illustrated that the adsorption was mainly controlled by the ion-exchange reaction. This study demonstrated that the MCHETC adsorption technology may be used for heavy metal removal and recovery with higher efficacy.
研究领域:
环境科学
·
材料科学
✓ 已验证
DOI
高影响因子
Toxics
·
2024
·Vol. 12
·期 7
·524
·
IF 3.9
Yuanzhen Li,Yinming Fan,Yanhong Wang,Yinian Zhu,Zongqiang Zhu,Shengpeng Mo,Xiaobin Zhou,Yanping Zhang
VOCs can be used instead of ammonia as a reducing agent to remove NO, achieving the effect of removing VOCs and NO simultaneously. Due to the high energy consumption and low photocatalytic efficiency required for conventional thermocatalytic purification, photothermal coupled catalytic purification can integrate the advantages of photocatalysis and thermocatalysis in order to achieve the effect of pollutants being treated efficiently with a low energy consumption. In this study, samples loaded with Co and Mn catalysts were prepared using the hydrothermal method on Fe-MOF with various morphologies. The catalytic performance of each catalyst was analyzed by studying the effects of their physicochemical properties through various characterizations, including XRD, SEM, BET, XPS, H2-TPR, TEM and O2-TPD. The characterization results demonstrated that the specific surface area, pore volume, high valence Co and Mn atoms, surface adsorbed oxygen and the abundance of oxygen lattice defects in the catalysts were the most critical factors affecting the performance of the catalysts. Based on the results of the performance tests, the catalysts prepared with an octahedral-shaped Fe-MOF loaded with Co and Mn showed a better performance than those loaded with Co and Mn on a rod-shaped Fe-MOF. The conversions of acetone and NO reached 50% and 64%, respectively, at 240 °C. The results showed that the catalysts were capable of removing acetone and NO at the same time. Compared with the pure Fe-MOF without Co and Mn, the loaded catalysts showed a significantly higher ability to remove acetone and NO simultaneously under the combination of various factors. The key reaction steps for the catalytic conversion of acetone and NO on the catalyst surface were investigated according to the Mars–van Krevelen (MvK) mechanism, and a possible mechanism was proposed. This study presents a new idea for the simultaneous removal of acetone and NOxby photothermal coupling.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
GREEN CHEMISTRY
·
2025
·Vol. 27
·期 17
·4540-4550
·
IF 9.2
Yang Zhao,Ruguang Wang,Jisi Li,Jiaxin Guo,Quanlu Wang,Zheng Lv,Pengfei Yin,Tao Ling
Single-atom catalysts towards the oxygen reduction reaction (ORR) often suffer from unsatisfactory activity and poor stability. Herein, for the first time, we successfully modulated the electronic structure of the Mn–N–C catalyst by introducing chalcogen oxygen groups (XO2, X = S, Se, Te), which induce changes in the Mn–N bond length in the MnN4 structure, thereby modulating the electronic structure of the metal center Mn. The experimental results demonstrate that the introduction of XO2 groups results in the rearrangement of Mn 3d electrons, which can be strongly correlated with the ORR activity of the Mn–N–C catalysts, among which the SeO2 modification increases the kinetic current density of the Mn–N–C catalyst achieving a half-wave potential (E1/2) of 0.79 V versus the reversible hydrogen electrode, approaching that of Fe–N–C catalysts along with significant stability in acidic media. The promising performance of the Mn–N–C catalyst as a PGM-free cathode was confirmed through fuel cell testing. First-principles calculations demonstrate that the introduced XO2 group downshifts the d-band center of the Mn center, thus successfully optimizing the adsorption of oxygen intermediates. This finding significantly facilitates the activity enhancement of Mn–N–C catalysts via the construction of a geometric structure–electronic structure–catalytic property relationship.
研究领域:
材料科学
·
电化学
·
能源科学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）