Nano Express
·
2020
·Vol. 1
·期 1
·010056
·
IF 0
Shuhong Xu,Ruohu Zhang,Hao Wu,Yiping Cui,Chunlei Wang,Haibao Shao
The incorporation of impurity cation as a way of introducing various novel functionalities provides an additional level of control over the electronic and optical properties of perovskite nanocrystals (NCs). However, the conventional post-synthetic cation exchange approaches suffer from large time and energy consumption. In this work, we developed a novel one-pot method to synthesize Mn-doped CsPbClxBr3−x NCs by merit of sonochemical technique, achieving dramatically rapid reduce of time and energy consumption. The localized hot spots with high transient temperature, pressure, and cooling rate, as well as an excellent stirring action of ultrasonic preparation facilitate the diffusion of Mn2+ in perovskite lattice. Besides, further reaction kinetics investigation reveals an apparent decrease of reaction order from original method (2.4) to our ultrasound-assisted method (1.0).
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DOI
Molecular Catalysis
·
2022
·
IF 5.089
Yi Yang,Jia Fang,Zhongwei Meng,Ping Pu,Qian Zhang,Chengcheng Yi,Suozhu Pan,Yalong Li
To solve the soot elimination and optimize catalyst diesel particulate filter (CDPF) regeneration strategies, a series of Mn-Ce catalysts with different Mn/(Mn+Ce) molar ratios are successfully synthetized by hydrothermal method and the complete catalytic oxidation of diesel engine soot are investigated. Compare to CeO 2 and MnO 2 , the catalytic promotion on soot combustion of Mn-Ce catalysts is more excellent by thermogravimetric experiments due to their better ability to activate oxygen species, which is consistent with results in characterization analysis. Among as-prepared catalysts, MC-0.40 has the best catalytic activity with the lowest starting temperature ( T s ), peak temperature ( T p ) and largest comprehensive combustion index ( S ) both in O 2 /N 2 and NO/O 2 /N 2 atmosphere. Influence factors on catalytic performance are studied. Weight ratios of soot/MC-0.40 catalyst are suitable at the range of 1:9–1:13, which makes soot combustion more easily. Ashes in the reaction process show adverse effects due to their ability to increase ignition point by inhibit heat and oxygen transfer. Mn-Ce catalysts are more sensitive and show better catalytic activity in NO atmosphere because of generations of abundant adsorbed species and NO adsorption/desorption. The three consecutive cycles of MC-0.40 catalyst are performed to study the catalytic stability, and thermogravimetric curves show that the potential reusability of MC-0.40 catalyst can be relatively accepted in soot combustion.
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JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2024
·
IF 9.4
Linna Dai,Xin Zhou,Yuan Yang,Pei Hu,Lijie Ci
Nonaqueous Li − O 2 battery (LOB) is considered one of the most promising energy storage system due to its ultrahigh theoretical specific capacity (3500 Wh kg −1 ). Introducing vacancies in CoMn 2 O 4 catalysts is regarded as an effective strategy to enhance the electrochemical performances of LOB. However, the relation between vacancy types in CoMn 2 O 4 and catalytic performances in the LOB remains ambiguous. Herein, ordered porous CoMn 2 O 4 with oxygen and metal vacancies is obtained via solvothermal reaction followed by temperature-controlled calcination using polystyrene spheres as templates. The increase in treatment temperature reduces the content of oxygen vacancies while increasing that of the metal vacancies. Notably, experimental results and theoretical calculations show that oxygen vacancies in CoMn 2 O 4 have a greater influence than metal vacancies in modulating the LiO 2 adsorption during the reaction processes and reducing the overpotential. CoMn 2 O 4 synthesized at 500 ℃ (CoMnO-500) with higher oxygen vacancies exhibits stronger adsorption onto the LiO 2 , facilitating the formation of film-like Li 2 O 2 . Therefore, an LOB with the CoMnO-500 catalyst presents the lowest overpotential of 1.2 V and longest cycle lifespan of 286 cycles at a current density of 200 mA g −1 . This study offers insights into the effect of CoMn 2 O 4 vacancies on the formation pathway of Li 2 O 2 discharge products.
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JOURNAL OF CATALYSIS
·
2024
·
IF 6.5
Fuping Song,Juping Zhang,Dongfang Li,Tao Zhu,Xing Zhu,Hua Wang
Oxidative dehydrogenation (ODH) of ethylbenzene is a promising process for styrene production. However, its application is limited by product overoxidation and purification requirements due to the co-feeding of mild oxidants. Herein, we report a facile manganese-based catalyst (K/Mn 3 O 4 -Al 2 O 3 ) and achieve competitive styrene selectivity of 88 % and ethylbenzene conversion of 95 % at 450 ℃ (84 % yield vs. ∼ 60 % yield in commercial dehydrogenation process at 600 ℃) under a cyclic redox ODH scheme. The introduction of Al 2 O 3 into MnO x restructures composite oxides and depresses bulk lattice-oxygen migration for the partial oxidation of ethylbenzene. The surface modification using potassium creates reactive sites and regulates surface properties, achieving ethylbenzene activation and high conversions. Highly active lattice oxygen in catalysts after bulk and surface modifications selectively converts ethylbenzene to styrene and water. This study provides an understanding of roles of manganese-based catalysts in styrene generation and offers a strategy to modulate lattice oxygen on catalysts.
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OPTICAL MATERIALS
·
2024
·
IF 3.8
Worku Lakew Kebede,Kuo Dong-Hau,Chen Xiaoyun
Metal oxide semiconductor photocatalysts have received remarkable consideration as a promising technology for environmental remediation and energy conversion. Oxysulfide semiconductors have narrow band gaps which are appropriate for photocatalytic removal of toxic organic pollutants under visible light illumination. For the elimination purpose of these pollutants, Mo(O,S) 2 , Mn(O,S) 2 , and Mn–Mo(O,S) 2 oxysulfide catalysts containing various Mn contents were synthesized at low temperatures via a simple method. The structural, morphological, electrochemical, compositional, and optical properties of the as-synthesized catalysts were exhaustively characterized. The photocatalytic degradation activity of the bares Mo(O,S) 2 , Mn(O,S) 2 , and other Mn–Mo(O,S) 2 compositions were evaluated over different types of organic pollutants under visible light illumination. The addition of Mn in Mo(O,S) 2 structure improved the photodegradation activity, and Mn–Mo(O,S) 2 -30 was found to be the best composition with superior photodegradation performance towards the four cationic, anionic, and neutral dyes. The degradation efficiency of 10 ppm of MB, and MO dyes reach 99.7 % and 98.6 %, within 30 and 120 min, respectively. Mn–Mo(O,S) 2 -30 catalyst also shows a good photodegradation performance on Rh B and NR organic pollutants. According to the recycling test, the catalyst exhibited excellent performance. The photodegradation follows pseudo-first order kinetics with a rate constant of 0.097 and 0.036 min −1 for MB and MO dyes, respectively. The trapping experiment showed that superoxide anion radicals (O 2 •- ) and holes (h + ) are the responsible active species for the degradation on MO and MB, respectively. The novelty of using Mn–Mo(O,S) 2 -30 for various dyes degradation lies in its remarkable catalytic properties.
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高影响因子
ACS Applied Materials & Interfaces
·
2022
·
IF 10.383
Xueqian Ji,Yuxing Xu,Qing Xia,Yuncheng Zhou,Jiechen Song,Hailan Feng,Pengfei Wang,Jun Yang,Qiangqiang Tan
With the increasing demand for high energy density and rapid charging performance, Li-rich materials have been the up and coming cathodes for next-generation lithium-ion batteries. However, because of oxygen evolution and structural instability, the commercialization of Li-rich materials is extremely retarded by their poor electrochemical performances. In this work, Li-deficient materials Li0.3NbO2 and (Nb0.62Li0.15)TiO3 are applied to functionalize the surface of Li1.2Mn0.54Ni0.13Co0.13O2, aiming to suppress oxygen evolution and increase structural stability in LIBs. In addition, a fast Li-ion transport channel is beneficial to enhance Li+ diffusion kinetics. The results demonstrate that the electrodes decorated with Li0.3NbO2 and (Nb0.62Li0.15)TiO3 materials exhibit more stable cycling stability after long-term cycling and outstanding rate capability.
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高影响因子
CRYSTENGCOMM
·
2019
·Vol. 21
·期 23
·3568-3575
·
IF 3.382
Kun Bai,Rihui Tan,Bao Ke,Xiaogang Xue,Jialong Zhao,Bingsuo Zou,Ruosheng Zeng
In recent years, halide perovskites have attracted great attention as a type of well-known material, especially inorganic perovskites like CsPbX3 (X = Cl, Br, and I). Herein, we introduce a new family of doped nanocrystals offering unique insights into the synthetic chemistry of doped perovskites. Mn-Doped Cs3Pb6.48Cl16 nanocrystals with pure dopant emission were prepared at room temperature with a low Mn/Pb feed ratio (>1.4). The band edge luminescence of Mn:Cs3Pb6.48Cl16 was almost completely inhibited, and the photoluminescence quantum yields (PL QYs) of Mn ions could reach up to 25%. Furthermore, the temperature-dependent PL spectra and temperature-dependent lifetime of the new family of doped nanocrystals indicated that the inflection point affects both the PL intensity and the PL lifetime of Mn2+ ions with increasing the temperature, which is related to the Mn/Pb ratio.
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高影响因子
Materials Research Express
·
2017
·Vol. 4
·期 8
·085028
·
IF 1.068
Guangguang Huang,Chunlei Wang,Shuhong Xu,Yiping Cui
For ultrasmall Mn-doped quantum dots (QDs), the energy transfer of the exciton to the Mn is the key factor for Mn emission. Herein, the Ag-induced electron trap state energy level, which is an intermediate energy level between the conduction band (CB) and 4T1 of Mn, is proposed for improving the energy transfer. After doping the Ag and forming Ag&Mn:ZnInS QDs, most excitons will first be captured by the intermediate energy level and then be transferred to Mn d-states, leading to enhanced photoluminescence (PL) quantum yields (QY) of the QDs from the original 17% (Mn:ZnInS QDs) to 30% (Ag&Mn:ZnInS QDs).
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高影响因子
DALTON TRANSACTIONS
·
2024
·Vol. 53
·期 4
·1849-1861
·
IF 3.5
Haodi Dong,Changcheng Liu,Que Huang,Yanjun Chen
Nowadays, the poor conductivity and unstable structure have become obstacles for the popularization of Na3V2(PO4)3 (NVP). In the current work, a dual-modified Mn0.1Cl0.3-NVP composite doped with Mn and Cl is prepared by a facile sol–gel method. When Mn2+ with a large ionic radius replaces small V3+, it can improve the stability of the NVP crystal structure. In addition, the replacement of V3+ by Mn2+ in a low valence state can generate redundant hole carriers, which is conducive to the rapid transport of electrons. The substitution of PO43− by Cl−, which is more electronegative, can reduce the impedance and facilitate the movement of Na+. Owing to the synergistic effect of Mn and Cl co-substitution, the structural stability of NVP was systematically enhanced, and the electron transfer and ion diffusion were effectively improved. Consequently, the optimized Mn0.1Cl0.3-NVP sample demonstrated superior electrochemical performance and kinetic properties. It exhibited a high reversible capacity of 109.2 mA h g−1 at 0.1C. Even at 15 and 30C, high discharge capacities of 70.3 mA h g−1 and 68.2 mA h g−1 were observed after 2000 cycles with capacity retention above 80%. Moreover, it delivered remarkable capacities of 77.1 and 73.4 mA h g−1 at 100 and 200C with retained capacity values of 50.3 and 47 mA h g−1, respectively, after 2000 cycles. Furthermore, the assembled Mn0.1Cl0.3-NVP//HC full cell delivered a high value of 94.7 mA h g−1 and lit LED bulbs, indicating its excellent application potential.
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高影响因子
CHEMICAL PAPERS
·
2025
·
IF 2.5
Zhao Chun-Yan,Hu Xiu-Li,Zhou Wei
Calcium looping represents a high-temperature method designed to capture CO 2 , making it appropriate for CO 2 capture from flue gases post-combustion in power plants after combustion or for integration with fuel transformation techniques in pre-combustion CO 2 sequestration systems. This method employs solid sorbents of CaO sourced from natural limestone, leveraging the chemical interaction of CaO with CO 2 , which ultimately results in the formation of CaCO 3 , thereby facilitating effective CO 2 capture. In this research, multiple metal-incorporated CaO-based sorbents were produced through the sol–gel method. Notably, the CaO-based sorbent with a Ca/Ce doping ratio of 15 demonstrates exceptional CO 2 capture ability and stability, maintaining 13.20 mmol/g of CO 2 adsorption capacity after 20 carbonation/calcination cycles. Various characterization techniques, including X-ray diffraction (XRD), N 2 physisorption, scanning electron microscopy (SEM), high-angle annular dark field scanning transmission electron microscopy/energy dispersive spectroscopy (HAADF-STEM/EDS), temperature-programmed-desorption with CO 2 (CO 2 -TPD), Fourier Transform Infrared Spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) are employed to demonstrate that the presence of nanoscale CeO 2 significantly enhanced the diffusion of CO 2 during the adsorption process.
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产品关联
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高影响因子
Journal of Environmental Chemical Engineering
·
2025
·
IF 7.2
Shuya Rui,Na Liu,Lingwei Ren,Yang Liu,Zian Liu,Binghui Wu,Hua Pan,Zhiping Ye
Traditional Mn-Ce catalysts for selective catalytic reduction (SCR) of NO with CO (CO-SCR) in iron and steel flue gases are often hindered by competitive adsorption of NO and CO, which compromises catalytic efficiency. In this study, we present a Ni-doped Mn-Ce catalyst that overcomes these challenges, achieving 96 % NO conversion, 98 % N 2 selectivity, and 44 % CO conversion at 175 °C. Comprehensive characterization of the catalyst reveals that Ni doping significantly enhances Mn-Ce interactions, boosting oxygen vacancy density and promoting efficient redox cycling between Mn 3 + /Mn 4+ and Ce 3+ /Ce 4+ . Diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) confirms preferential NO adsorption at oxygen vacancy sites, minimizing CO-NO competition and stabilizing the Langmuir-Hinshelwood mechanism, where both gases co-adsorb and react at oxygen-rich vacancies. Mechanistic insights suggest that Ni facilitates electron transfer, weakening the N–O bond in NO and accelerating its dissociation, resulting in faster NO reduction. This study establishes Ni doping as a promising strategy for improving the low-temperature performance of Mn-Ce-based CO-SCR catalysts, paving the way for more efficient catalytic systems.
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DOI
高影响因子
CERAMICS INTERNATIONAL
·
2025
·
IF 5.6
Zhengqing Pei,Jiawei Wang,Haifeng Wang,Kexin Zheng,Qian Wang,Xinjie Zhou,Dehua Ma,Ju Lu,Haijiao Xie
The spinel-structured LiMn 2 O 4 cathode material exhibits low specific capacity and rapid capacity decay under high current densities , significantly limiting its commercial application prospects. This study uses a coprecipitation and calcination method to dope Zn into LiMn 2 O 4 , discovering that doping Zn elements causes LiMn 2 O 4 to preferentially grow along the (110) and (100) crystal planes. The (110) and (100) crystal planes provide more Li ion channels, contributing to the improvement of rate performance. In the custom-designed LiZn 0.04 Mn 1.96 O₄ (LZMO-0.04) cathode, the strategic addition of Zn occupying Mn sites makes electrons more delocalized, increasing the free electron gas and enhancing the material’s conductivity. The LZMO-0.04 sample exhibits a rich variety of polymorphic morphologies, a lower Mn³⁺ content, and a higher Li⁺ diffusion coefficient . These optimization effects, resulting from the synergistic action of multiple factors, enabled the LZMO-0.04 sample to achieve an initial discharge capacity of 127.73 mAh/g with a capacity retention rate of 83.06 % after 300 cycles at a rate of 0.5C. Even with an increase to a high rate of 5 C over 1200 cycles, the capacity retention rate remained stable at 81.89 %, exhibiting excellent high-rate cycle stability.
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