Catalysis Science & Technology
·
2015
·Vol. 5
·期 5
·2959-2972
·
IF 5.426
Ran Zhang,Li Guo,Chen Chen,Jizhong Chen,Angjun Chen,Xiuge Zhao,Xuerui Liu,Yuhe Xiu,Zhenshan Hou
A novel highly active Mn-doping ceria heterogeneous catalyst (MnOx–CeO2) was prepared and dedicated to the catalytic synthesis of aliphatic carbamates from CO2, aliphatic amines and methanol in one step. The as-obtained catalyst can attain a high yield of carbamate up to 82%, and can also be recycled at least four times through a simple procedure. It was observed that the Mn doping to ceria can alleviate the catalyst deactivation in consecutive catalytic recycles. In this regard, the role of Mn doping in the ceria in the synthesis of the aliphatic carbamates was investigated by means of X-ray diffraction (XRD), Raman spectra, specific surface areas (BET), thermogravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS), CO2-temperature programmed desorption (CO2-TPD) and in situ diffuse reflectance infrared Fourier transform (DRIFT). The characterization demonstrated that the presence of MnOx in the ceria can not only inhibit the formation of stable carbonate species on the surface of the catalyst but also promote the decomposition/consuming of the carbonaceous species during the synthesis of aliphatic carbamates so as to allow improvement of the recyclability of the catalyst.
研究领域:
催化化学
·
材料科学
✓ 已验证
DOI
高影响因子
ANALYTICAL LETTERS
·
2024
·
IF 1.6
Jing Yang,Zhe Lv,Bo Yang,Xiangdong Guo,Feiyong Qu,Yanping Miao,Dehui Li,Hongmei Gao,Wei Li
Photoluminescence enhancement provides an effective way to improve the performance of quantum dots. In this study, lead(II) determination was demonstrated based on phosphorescence enhancement using 1-thioglycerol-capped Mn-doped ZnS quantum dots. Under the optimized conditions, good linear correlations were obtained for Pb2+ from 10.00 to 5000 nM and 0.05000 to 100.0 mM with correlation coefficients of 0.9997 and 0.9979 and a detection limit of 2.56 nM. The method demonstrates good linearity and selectivity, suitable sensitivity, easy operation, and the determination of Pb2+ in Chinese herbal medicine.
研究领域:
分析化学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2025
·
IF 8.2
Yifeng Xia,Hua Hao,Cheng Tao,Minghe Cao,Zhonghua Yao,Hanxing Liu
Dielectric capacitors are essential in advanced electronics and power systems due to their high power density and fast charge–discharge rates. However, their application is limited by their low energy storage density and efficiency. Aurivillius-phase ferroelectrics have shown promise as energy storage materials, but their low polarization and significant hysteresis remain critical challenges. In this study, we present a simple and cost-effective defect-engineering strategy to enhance the energy storage performance of SrBi5Ti4FeO18 thin film through Mn doping. Mn incorporation suppresses oxygen vacancy formation and induces tensile chemical stress in the lattice, which simultaneously enhances maximum polarization and reduces the hysteresis. Additionally, the reduction in oxygen vacancies promotes grain refinement, reduces leakage current, and significantly enhances the breakdown strength. The optimized SrBi5Ti3.91Mn0.09FeO18 thin film achieves an ultrahigh energy storage density of 105 J/cm3 with improved efficiency of 70% at 3569 kV/cm. Moreover, it demonstrates good frequency stability (100 Hz to 10 kHz), thermal stability (20–160 °C), and fatigue endurance over 105 cycles. This work provides a feasible method for developing advanced dielectric capacitors with high energy storage performance by the rational design and precise control of defects.
研究领域:
材料科学
·
电子工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Jiahao Liu,Qingnian Li,Hanyu Tu,Jie Feng,Xiaofei Fan,Ze Mi,Hongpei Han,Xiaoqian Ma,Qi Liang,Zheng Zhang,Hongshuai Hou,Pengfei Rong,Wenhu Zhou
Radiotherapy is a cornerstone in the treatment of malignant tumors, yet its efficacy is often hindered by intrinsic and acquired resistance mechanisms, notably limited radiation availability and tumor hypoxia within inner tumor region. This study introduces a multifunctional nanosensitizer, CD Bi,Mn-FA @CaP, with high tumor accumulation and deep penetration capabilities via dynamic conformational change. CD Bi,Mn-FA was bismuth manganese-doped carbon dots, offering radiosensitizing properties and catalase-like activity for oxygen generation. Folic acid modification further enhances tumor cell targeting. These carbon dots are encapsulated in calcium phosphate nanoparticles to form CD Bi,Mn-FA @CaP, which demonstrates improved in vivo circulation and tumor accumulation via the enhanced permeability and retention (EPR) effect. Upon encountering the acidic tumor microenvironment, the encapsulation degrades, releasing smaller CD Bi,Mn-FA particles that deeply penetrate tumor tissues. In vitro and in vivo experiments establish that CD Bi,Mn-FA @CaP effectively targets tumor tissue, enhances radiotherapy-induced apoptosis, and suppresses tumor growth. Notably, the nanoparticle achieves a 40 % tumor cure rate and ensures 100 % survival within 45 days post-treatment. Biocompatibility studies confirm minimal systemic impact, with efficient renal and fecal elimination, indicating promising clinical translational potential. This study introduces a novel radiation therapy sensitization strategy and underscores the potential of such size changeable nanoparticles as an advanced targeted drug delivery system for tumors.
研究领域:
生物医学工程
·
肿瘤学
·
纳米医学
✓ 已验证
产品关联
DOI
高影响因子
Water
·
2024
·Vol. 16
·期 13
·1795
·
IF 3
Mengxue Li,Lanbao Zhu,Jing Wang,Li Ma,Zhengwei Pan,Wenwei Ji,Xiaoyu Sun,Ruping Li,Xia Li,Shilong Duan,Yule Tao
Mn-substituted FeOOH with different Mn/(Mn + Fe) molar ratios are synthesized, and characterized using FESEM, XRD, FTIR, ICP-OES, BET, Zeta potential, TG-DSC, XPS, and VSM. The results show that the actual doping amounts of Mn are 0%, 3.05%, 6.13%, 9.04%, 12.70%, and 15.14%, respectively. The substitution of Mn promotes the transformation of goethite from FeOOH to MnFe2O4, resulting in a saturation magnetization intensity of up to 14.90 emu/g for G-Mn15%, laying a theoretical foundation for magnetic recovery. The specific surface area of Mn-substituted FeOOH increases from 57.15 m2/g to 315.26 m2/g with an increasing Mn substitution amount. Combined with the abundant oxygen-containing functional groups such as -OH, Fe-O, and Mn-O on the surface, sufficient active sites are provided for the efficient adsorption of U(VI). The TG-DSC analysis results indicate that the substitution of Mn improves the thermal stability of goethite. In addition, XPS analysis results indicate that the substitution of Mn leads to the conversion of Fe3+to Fe2+in goethite, and the conversion of Mn2+to Mn3+replaces Fe3+in the structure of goethite. Fe-O and Mn-O coordinate participate in the adsorption and reduction process of U(VI). The batch experiment results show that the substitution of Mn promotes the adsorption performance of goethite for U(VI). When T = 303 K, pH = 4.0, m/V = 0.5 g/L, and I = 0.01 mol/L NaCl, the maximum adsorption capacity of G-Mn15% for U(VI) is 79.24 mg/g, indicating the potential value of Mn substitution for goethite in the treatment of uranium-containing wastewater.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2021
·
IF 8.128
Pei Liu,Weiquan Cai,Junwu Chen,Zhichao Yang,Jinpeng Zhou,Zhijun Cai,Jiajie Fan
Mn-doped activated carbon microspheres (MnO x /ACS) with super-high adsorption capacities and deep removal capability for hexavalent chromium (Cr(VI)) were successfully prepared via an ammonium persulfate-assisted hydrothermal method followed by potassium oxalate activation using KMnO 4 and sucrose as raw materials. Their -physical and chemical properties, as well as those of Mn-doped non-activated carbon spheres (MnO x /CS), were characterized by XRD, SEM, TEM, EDS-mapping, XPS, N 2 adsorption–desorption, ICP-AES, and elemental analysis. It was found that the manganese oxide (MnO x ) particles were uniformly embedded within the carbon spheres via layer-by-layer capture, and the MnO x /ACS exhibited strong redox activity because of the multivalent nature of MnO x , resulting in excellent adsorption performance via reduction. In particular, MnO x /ACS-4 with a Mn content of 1.06 wt% and a specific surface area of 1405.7 m 2 g −1 achieved a maximum adsorption capacity of 660.7 mg g −1 ; this can reduce Cr(VI) content to less than 0.05 mg L -1 , which meets the corresponding Chinese drinking water quality standard when the initial concentration of Cr(VI) is less than 400 mg L -1 . Furthermore, this highly efficient method can be extended to prepare V-, Mo-, or W-doped carbon microspheres with significantly enhanced adsorption performance for Cr(VI) compared to bare activated carbon sphere, indicating their good application prospect for the deep removal for heavy metal ions from wastewater.
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
ELECTROCHIMICA ACTA
·
2022
·
IF 7.336
Tao Xu,Fanghui Du,Ling Wu,Zhongxu Fan,Lina Shen,Junwei Zheng
The urgent demands of developing Co-free materials for lithium ion batteries with high energy density for next generation electric vehicles have driven the attention of researches to LiNiO 2 stabilized by doping of common elements. Among those elements, manganese is usually used to stabilize cathode material crystal structures to achieve better electrochemical performances. However, the Li + /Ni 2+ cation disorder causing by Mn doping is greatly neglected of the effect on electrochemical behaviors. In order to elucidate the exact effect of Mn-doping, herein, we synthesize Mn-doped LiNiO 2 with extra low Mn content by using the solid-state element thermal interdiffusion strategy. Under calcination at high temperature, with the spherical species coated with Mn-containing gel as the precursor, Mn can be evenly doped into the framework of LiNiO 2 material. It is demonstrated that the small amount of Mn-doping can greatly stabilize both the crystal structure of LiNiO 2 and integrity of the secondary particles during the electrochemical cycling to provide the excellent electrochemical cycling performance and thermal stability of the materials. Nevertheless, the rate capability of the materials is strongly dependent on the amount of the doped Mn, due to the Li + /Ni 2+ cation mixing formed in the synthesis process and introduced in the electrochemical cycling. In the presence of a tiny quantity of the doped Mn, the enlarged crystal lattice would be favorable to the diffusion of the Li + ions in the crystal. However, serious Li + /Ni 2+ cation mixing of the materials with high content of the Mn-doping deteriorates the rate performance of the materials. Thus, in this case, the Mn content is optimized to be 4 mol%, endowing the material with an initial capacity of 202 mAh g −1 at 0.1 C, and a capacity retention of 85.41% after 200 cycles at 0.5 C. For the Mn-doped LiNiO 2 materials, it is suggested that to control the Li + /Ni 2+ cation mixing would be crucial for gaining the materials with superior electrochemical performance.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF LUMINESCENCE
·
2021
·
IF 3.599
Yanbin Li,Chaoyang Ma,Wanggui Ye,Chuandong Zuo,Yuzhen Wang,Xiaofei Shen,Zhanglin Chen,Chen Chang,Xuanyi Yuan,Yongge Cao
Developing new phosphor ceramics with higher thermal conductivity is a matter of priority for high power solid-state lighting. Herein, translucent red-emitting AlN : Mn phosphor ceramic with high thermal conductivity (72.37 W m −1 K −1 at 25 °C) and high luminescence thermal stability are successfully fabricated by pressureless sintering at 1800 °C for 3 h. Preparation process, photoluminescence , afterglow and electronic compensation mechanisms were discussed in detail. TEM analysis showed that the tiny grain boundaries are composed of disordered Al 2 O 3 phases. The EPR and TL spectra were used to reveal the O-related trap distribution. The AlN: Mn phosphor ceramics have brightly red afterglow with the longest afterglow time of 88 s and possess high luminescence thermal stability, that is to say, the luminescence intensity at 250 °C preserves 93.7% of that at room temperature . The encapsulated AlN: Mn LED device has a very bright red emission peak at 598 nm with a color purity of about 99%, indicating great application potential in solid-state lighting.
研究领域:
材料科学
·
光学工程
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2022
·
IF 7.139
Zhijie Zhang,Simin Chen,Sipeng Chen,Zeyu Yuan,Yanxiong Fang,Dai Dang,Yuying Zheng
Designing an electrocatalyst for hydrogen production from water splitting that is highly efficient, stable, and free of noble metals is necessary but challenging. The phosphorus compound is considered a viable candidate for producing hydrogen from water split, but its electrocatalytic performance needs further improvement. Herein, we present an easy and straightforward method for constructing Mn-doped Co 2 P yolk-shell lychee spheres. The Co nano prisms are used as a self-sacrificing template to conduct an ion exchange reaction with manganese ions, constructing Co oxide yolk-shell spheres with Mn–Co hydroxide nano-blocks. After in-suit phosphating at low temperature, Mn-doped Co 2 P with yolk-shell structure and lychee morphology is formed. The Mn-doped Co 2 P with an optimized Mn and Co molar ratio (0.125) exhibits excellent hydrogen evolution performance in alkaline and acidic electrolyte. The overpotentials can reach 10 mA cm −2 at 98 mV and 72 mV, respectively, and the Mn–Co 2 P-0.125 catalyst has faster electron transfer efficiency and larger electrochemically active surface area. The experimental results ascertain that doping an appropriate amount of Mn significantly changes the morphology and structure, thereby affecting the exposure of active sites, and modulating the electronic structure around Co 2 P. Under the dual regulation of morphology and electronic structure, the electrocatalytic process is accelerated, enhancing its catalytic activity .
研究领域:
材料科学
·
能源化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2022
·
IF 6.371
Yumeng Liang,Weiquan Zhan,Yuan Yuan,Noe Zamora-Romero,Feifei Jia,Bingqiao Yang,Zamoniddin Nasrddinov,José Luis Arauz-Lara,Shaoxian Song
The necessity for application of molybdenum disulfide (MoS 2 ) in photocatalytic reduction field required speedy improvement with high reduction and adsorption performance. Here, manganese (Mn) and oxygen (O) dual-doping strategy were taken for demonstrating that enhancing photocatalytic reduction could achieve simultaneous modulation of the reduction and adsorption parameters by optimizing the electronic configuration and hydrophilicity ability in MoS 2 . Benefiting from the Mn and O dual-doping collective effect, the developed Mn,O-MoS 2 exhibited outstanding photocatalytic reduction and recovery performances of gold(I) from thiosulfate leaching solutions with reduction capacity of 1386.98 mg/g and the corresponding recovery of 92.50%. Besides, Mn and O atoms dual doping in MoS 2 accelerated the recovery rate, which was 3 folds higher compared with that of MoS 2 . Experimental and first-principle approaches suggested that the reduction and adsorption ability of MoS 2 were strengthened through tuning the electronic structure and surface property with Mn and O dopants : (1) Mn atoms notably enhanced the conductivity and optimized the electronic structure for facilitating the reduction performance; (2) The incorporated O atoms greatly promoted the adsorption of [Au(S 2 O 3 ) 2 ] 3- by improving the affinity of water molecules and Mn,O-MoS 2 . The work provides a promising strategy to manipulate two-dimensional materials for various applications about catalysts and adsorbent.
研究领域:
材料科学
·
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
Small
·
2023
·
IF 13.3
Xiao Gong,Qingqing Xu,Jiurong Li,Yan Ma,Xiaoyan Li,Wanze Wu,Hangxiang Wang
The aggregation-caused quenching has always limited the high concentration and solid-state applications of carbon nanodots. While the aggregation-induced emission effect, dominated by intramolecular motion, may be an effective means to solve this problem. Here, hydrophobic solid-state red-light carbon nanodots (M-CDs) with 95% yield are synthesized by a one-step hydrothermal method using 2,2'-dithiodibenzoic acid as the carbon source and manganese acetate as the dopant source. The disulfide bond of 2,2'-dithiodibenzoic acid serves as the symmetry center of molecular rotation and Mn catalyzes the synthesis of M-CDs, which promotes the formation of the central graphitic carbon structure. The M-CDs/agar hydrogel composites can achieve fluorescence transition behavior because of the special fluorescence transition properties of M-CDs. When this composite hydrogel is placed in water, water molecules contact with M-CDs through the network structure of the hydrogels, making the aggregated hydrogels of M-CDs fluorescence orange-red under 365 nm excitation. While in dimethyl sulfoxide, water molecules in the hydrogels network are replaced and the M-CDs fluoresce blue when dispersed, providing a potential application in information encryption. In addition, high-performance monochromatic light-emitting diode (LED) devices are prepared by compounding M-CDs with epoxy resin and coating them on 365 nm LED chips.
研究领域:
材料科学
·
化学
·
光学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
RSC Advances
·
2019
·Vol. 9
·期 5
·2343-2352
·
IF 3.049
Feng Zhao,Shuangde Li,Xiaofeng Wu,Renliang Yue,Weiman Li,Yunfa Chen
CuO–CeO2 nanocatalysts with different amounts of Mn dopping (Mn/Cu molar ratios of 0.5 : 5, 1 : 5 and 1.5 : 5) were synthesized by flame spray pyrolysis (FSP) method and tested in the catalytic oxidation of CO. The physicochemical properties of the synthesised samples were characterized systematically, including using X-ray diffraction (XRD), Raman spectroscopy, field-emission scanning electron microscopy (FESEM), Brunauer–Emmett–Teller (BET), X-ray photoelectron spectroscopy (XPS), oxygen-temperature programmed desorption (O2-TPD), hydrogen-temperature programmed reduction (H2-TPR) and in situ diffuse reflectance infrared Fourier transform spectroscopy (in situ DRIFTS). The results showed that the 1Mn–Cu–Ce sample (Mn/Cu molar ratio of 1 : 5) exhibited superior catalytic activity for CO oxidation, with the temperature of 90% CO oxidation at 131 °C at a high space velocity (SV = 60 000 mL g−1 h−1), which was 56 °C lower than that of the Cu–Ce sample. In addition, the 1Mn–Cu–Ce sample displays excellent stability with prolonged time on CO stream and the resistance to water vapor. The significantly enhanced activity was correlated with strong synergetic effect, leading to fine textual properties, abundant chemically adsorbed oxygen and high lattice oxygen mobility, which further induced more Cu+ species and less formation of carbon intermediates during the CO oxidation process detected by in situ DRIFTS analysis. This work will provide in-depth understanding of the synergetic effect on CO oxidation performances over Mn doped CuO–CeO2 composite catalysts through FSP method.
研究领域:
催化化学
·
材料科学
·
环境科学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）