Journal of Physical Chemistry C
·
2021
·
IF 4.126
Qianrui Lv,Chong Li,Lijing Zhang
Developing strategies to modify lead-based metal halide perovskite lattice has become an increasingly important effort because of the need to control fundamental material properties. In this paper, we introduced a flow microreactor for the continuous synthesis of Mn-substituted methylammonium lead tribromide (CH3NH3Pb1–xMnxBr3) quantum dots. The original crystal structure can be retained at high Mn content (x = 0.3). The size and photoluminescence peak of the CH3NH3Pb1–xMnxBr3 quantum dots can be tuned by varying the molar ratio of Pb/Mn. With increasing Mn content, the photoluminescence peak shifted gradually to shorter wavelengths. Mn-substitution also affects the air stability for the quantum dots. CH3NH3Pb0.7Mn0.3Br3 shows the best air stability, and polystyrene can be used to protect the quantum dots. Compared to CH3NH3PbBr3 quantum dots, CH3NH3Pb1–xMnxBr3 quantum dots may prove to be a less toxic and valuable optoelectronic material meeting the requirements for different practical applications.
研究领域:
材料科学
·
光学
✓ 已验证
DOI
高影响因子
Journal of Saudi Chemical Society
·
2015
·
IF 2.523
Lijie Wang,Xi Zhang,Peng Zhang,Zetan Cao,Junhua Hu
Mn doped TiO 2 was synthesized by hydrothermal treatment of titanium boride and manganese chloride. The doped nano powders were fabricated by adding ammonium water into the mother solution which was obtained hydrothermally. The calcination of precursory powders took place at the temperature of 400–600 °C which resulted in the formation of anatase with a small amount of rutile phase. The shift of valence band maximum (VBM) toward the lower binding energies was observed by measuring the position of VBM with reference to the Fermi level, which contributed to the significant red-shift of absorption edges. X-ray photoelectron spectroscopy (XPS) measurement shows that manganese exists in both 4+ and 3+ valance states, which may have a temperate replacing of Ti 4+ because of the charge compensation compared with 2+ and 3+ valence states. The property of photoelectric conversion was detected by evaluating the photocurrent under visible light (>420 nm), and the fluorescence spectra also proved that 6%-Mn doped TiO 2 (DM6) shows a better photoelectric conversion performance.
研究领域:
材料科学
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光催化
✓ 已验证
DOI
高影响因子
Environments
·
2024
·Vol. 11
·期 7
·136
·
IF 3.5
Junhao Zheng,Mei Jiang,Qingzhu Li,Weichun Yang
Fe/Mn (hydr)oxides are metallic compounds that exhibit significant redox activity in environmental media and play a pivotal role in geochemical processes, thereby influencing the fate of metals in porous media. The morphology of Fe/Mn (hydr)oxides in natural environments and their interactions with trace metals are significantly influenced by the presence of natural organic matter (NOM). However, there is limited understanding regarding the formation, transport, and stability of Fe/Mn (hydr)oxides in the environment. The present study employed humic acid (HA) as a representative NOM material to investigate the positive influence of HA on the formation of Fe/Mn colloids. However, there remains limited comprehension regarding the formation, transport, and stability of Fe/Mn (hydr)oxides in the natural environment. In this study, we investigated the positive effect of natural organic matter (NOM) on the formation of Fe/Mn colloids using humic acid (HA) as a representative NOM material. We comprehensively characterized the chemical and physical properties of HA–Fe/Mn colloids formed under various environmentally relevant conditions and quantitatively analyzed their subsequent aggregation and stability behaviors. The findings suggest that the molar ratios of C to Fe/Mn (hydr)oxide play a pivotal role in influencing the properties of HA–Fe/Mn colloids. The formation and stability of HA–Fe/Mn colloids exhibit an upward trend with increasing initial molar ratios of C to Fe/Mn. Redox and metal–carboxylic acid complexation reactions between HA and hydrated iron/manganese oxides play a pivotal role in forming colloidal HA–Fe/Mn complexes. Subsequent investigations simulating porous media environments have demonstrated that the colloidal structure resulting from the interaction between HA and Fe/Mn facilitates their migration within surrounding porous media while also enhancing their retention in the surface layers of these media. This study offers novel insights into the formation and stabilization mechanisms of HA–Fe/Mn colloids, which are pivotal for comprehending the behavior of Fe/Mn colloids and the involvement of Fe/Mn (hydr)oxides in geochemical cycling processes within porous media.
研究领域:
环境科学
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地球化学
·
胶体化学
✓ 已验证
产品关联
DOI
高影响因子
FUEL
·
2023
·
IF 7.4
Xin Guo,Zhiyong Ding,Na Kang,Liu Yang,Yuanjiang Wang,Cheng Zhang,Zhaoqiang Li,Tiantian Zhang,Yan Wang,Yu Wang,Hao Qu
The zeolite-based catalyst is a promising option for the selective catalytic reduction (SCR) of nitrogen oxides (NO x ) due to its low toxicity. However, the challenge lies in its low-temperature activity. This study developed a multi-component catalytic system consisting of Ce/Mn/Cu-loaded Beta zeolite to reduce NO x . With fixed contents of Cu and Mn, we investigated the NH 3 -SCR process and the mechanism of action of the rare-earth species (i.e., Ce) in the system. Upon optimization of the content of Ce, the Ce/Mn/Cu-loaded Beta zeolite demonstrated enhanced low-temperature activity compared to samples loaded with Cu or Cu/Mn in the temperature range of 150–250 °C. When Ce was loaded in an appropriate proportion, it regulated the oxidation state of Cu, optimizing active adsorption species for NO and strengthening the strength of Brønsted acid sites in the catalyst. These synergetic effects led to improved NH 3 -SCR catalytic performance. This study can contribute to a better understanding of multiple metal-loaded zeolites in the NH 3 -SCR process and inform future design of Beta-type catalysts.
研究领域:
催化化学
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
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2022
·
IF 24.319
Menglu Xu,Yibing Zhang,Huaqin Yin,Jinnan Wang,Aimin Li,Philippe François-Xavier Corvini
Co-ZFO@Mn-CN with 1 O 2 and O 2 •− as main reactive oxygen species was synthesized for catalytic ozonation , which could efficiently degrade organic pollutants . EPR and XPS analysis indicated that lattice doping of Co induced formation of abundant of OVs, which could provide localized electrons for O 3 activation with the generation of HO 2 • /O 2 •− . 1 O 2 and H 2 O 2 were produced by the recombination of HO 2 • /O 2 •− . DFT calculation demonstrated that H 2 O 2 was deprotonated to generate HOO − , which preferred to form HOO-Mn-N X bonds with Co-ZFO@Mn-CN. Under the attack of O 3 , HOO-Mn-N X bonds were broken with the generation of HO 2 • and HO 3 • /O 3 •− , not only accelerating 1 O 2 production for organics degradation but also avoiding Mn(Ⅱ) sites oxidation . Combining advantages of OVs and HOO-Mn-N X , Co-ZFO@Mn-CN achieved 70–100% mineralization for different organic pollutants . Thus, this work provided a simple and efficient way for enhancing the utilization of O 3 by the synergistic effect of OVs and HOO-Mn-N X bonds, also improving ROS transformation.
研究领域:
环境科学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2017
·Vol. 53
·期 2
·1286-1296
·
IF 2.599
Cao Sheng,Zheng Jinju,Dai Chencheng,Wang Lin,Li Chengming,Yang Weiyou,Shang Minghui
In this report, doping concentration-dependent photoluminescence (PL) properties of Mn-doped ternary Zn–In–S quantum dots (QDs) were studied by using steady-state and time-resolved PL spectroscopy. The QDs PL was firstly significantly intensified with the increasing Mn doping concentration and then decreased after the doping concentration increased up to 7.5 at.%. However, their decay lifetimes exhibit a monotone decrease with Mn doping concentration ranged from 0 to 10 at.%. It can be concluded that the PL intensity was mainly determined by two factors: one was the increased efficiency of energy transfer from host excitons to Mn 2+ ion accepter, and the other was the decreased efficiency of the emission from a Mn 2+ ion, which was caused by the increased component of exposed Mn 2+ ions on QDs surface and the accelerated interaction between adjacent dopants. The competition of above two exciton relaxation dynamics processes determined the trend of the PL intensity, while the latter was responsible for the monotonously decreased lifetime of the Mn 2+ ion emission with the increasing Mn doping concentration.
研究领域:
材料科学
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光学
✓ 已验证
产品关联
DOI
高影响因子
Catalysts
·
2018
·Vol. 8
·期 12
·642
·
IF 3.465
Yan Gao,Tao Luan,Mingyang Zhang,Wenke Zhang,Wenchen Feng
A series of Mn−Fe−Ce−Ox/γ-Al2O3nanocatalysts were synthesized with different Mn/Fe ratios for the catalytic oxidation of NO into NO2and the catalytic elimination of NOxvia fast selective catalytic reduction (SCR) reaction. The effects of Mn/Fe ratio on the physicochemical properties of the samples were analyzed by means of various techniques including N2adsorption, scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), H2-temperature-programmed reduction (TPR), NH3-temperature-programmed desorption (TPD) and NO-TPD, meanwhile, their catalytic performance was also evaluated and compared. Multiple characterizations revealed that the catalytic performance was highly dependent on the phase composition. The Mn15Fe15−Ce/Al sample with the Mn/Fe molar ratio of 1.0 presented the optimal structure characteristic among all tested samples, with the largest surface area, increased active components distributions, the reduced crystallinity and diminished particle sizes. In the meantime, the ratios of Mn4+/Mnn+, Fe2+/Fen+and Ce3+/Cen+in Mn15Fe15−Ce/Al samples were improved, which could enhance the redox capacity and increase the quantity of chemisorbed oxygen and oxygen vacancy, thus facilitating NO oxidation into NO2and eventually promoting the fast SCR reaction. In accord with the structure results, the Mn15Fe15−Ce/Al sample exhibited the highest NO oxidation rate of 64.2% at 350 °C and the broadest temperature window of 75–350 °C with the NOxconversion >90%. Based on the structure–activity relationship discussion, the catalytic mechanism over the Mn−Fe−Ce ternary components supported byγ-Al2O3were proposed. Overall, it was believed that the optimization of Mn/Fe ratio in Mn−Fe−Ce/Al nanocatalyst was an extremely effective method to improve the structure–activity relationships for NO pre-oxidation and the fast SCR reaction.
研究领域:
环境科学
·
催化化学
✓ 已验证
DOI
高影响因子
JOURNAL OF CHEMICAL CRYSTALLOGRAPHY
·
2022
·Vol. 53
·期 1
·145-151
·
IF 0.582
Zhang Lirong,Qi Feiyan,Shele Muge,Namila E.,Qi Liming,Baiyin Menghe
One quaternary selenidoantimonate of [Mn(en) 3 ]CdSb 2 Se 5 ( 1 ) (en = ethylenediamine) was prepared under 1,2-propanediamine condition by mild solvothermal method. Single-crystal X-ray diffraction analysis reveals that compound 1 crystallizes in the monoclinic space group C 2/c. Its structure consists of infinite 1D [CdSb 2 Se 5 ] n 2n− anionic chains and [Mn(en) 3 ] 2+ cations. Meanwhile, “Z” shaped eight-membered [Cd 2 Sb 2 Se 4 ] and six-membered [CdSb 2 Se 3 ] rings are alternately found. As estimated from UV–Vis absorption spectrum, the band gap of 1 is 2.58 eV. Compound 1 also showed rapid response and excellent reproducibility based on photoelectric test. In addition, the magnetic and other properties of 1 were studied. Graphical Abstract The manuscript describes the synthesis, crystal structure, single-crystal X-ray diffraction, elemental analysis, photoelectric response, thermogravimetric analysis, magnetic properties, infrared spectroscopy and UV-Vis diffuse reflectance spectroscopy of [Mn(en) 3 ]CdSb 2 Se 5 . The photoelectric response of compound 1 was explored, and a highly repetitive and stable photocurrent curve was found, indicating that 1 is a typical p-type semiconductor. In addition, the magnetism of compound 1 was also studied, which showed that 1 had antiferromagnetic behavior.
研究领域:
材料科学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
Surfaces and Interfaces
·
2025
·
IF 6.3
Jing Fan,Liang Guo,Fenhong Song
This study employed the hydrothermal method to dope Mn into Sn 3 O 4 , which was then combined with g-C 3 N 4 through calcination to prepare an II-type Mn-Sn 3 O 4 -x/CN composite photocatalyst. The impact of Mn-Sn 3 O 4 loading on the photocatalytic performance was discussed. The synthesized composite catalysts exhibited remarkable hydrogen production performance under visible light, with Mn-Sn 3 O 4 -10/CN demonstrating the highest performance. Characterization techniques confirmed the successful preparation of the catalysts, and the light absorption capacity, charge separation and transport efficiency of Mn-Sn 3 O 4 -10/CN are significantly improved compared to catalysts with other ratios. This study developed a Mn-Sn 3 O 4 -x/CN composite catalyst with high stability and good hydrogen production rate. It provides further directions for the research of g-C 3 N 4 -based composite catalysts.
研究领域:
材料科学
·
能源科学
✓ 已验证
产品关联
DOI
高影响因子
Nanomaterials
·
2020
·Vol. 10
·期 9
·1745
·
IF 4.324
Ze Sun,Liuting Zhang,Nianhua Yan,Jiaguang Zheng,Ting Bian,Zongming Yang,Shichuan Su
Magnesium hydride (MgH2) has been considered as a potential material for storing hydrogen, but its practical application is still hindered by the kinetic and thermodynamic obstacles. Herein, Mn-based catalysts (MnCl2and Mn) are adopted and doped into MgH2to improve its hydrogen storage performance. The onset dehydrogenation temperatures of MnCl2and submicron-Mn-doped MgH2are reduced to 225 °C and 183 °C, while the un-doped MgH2starts to release hydrogen at 315 °C. Further study reveals that 10 wt% of Mn is the better doping amount and the MgH2+ 10 wt% submicron-Mn composite can quickly release 6.6 wt% hydrogen in 8 min at 300 °C. For hydrogenation, the completely dehydrogenated composite starts to absorb hydrogen even at room temperature and almost 3.0 wt% H2can be rehydrogenated in 30 min under 3 MPa hydrogen at 100 °C. Additionally, the activation energy of hydrogenation reaction for the modified MgH2composite significantly decreases to 17.3 ± 0.4 kJ/mol, which is much lower than that of the primitive MgH2. Furthermore, the submicron-Mn-doped sample presents favorable cycling stability in 20 cycles, providing a good reference for designing and constructing efficient solid-state hydrogen storage systems for future application.Keywords:hydrogen storage;MgH2;Mn-based catalysts;catalytic effect;reversibility
研究领域:
材料科学
·
化学工程
·
能源存储
✓ 已验证
产品关联
DOI
PubMed
高影响因子
OPTICAL MATERIALS
·
2019
·
IF 2.687
Mingrui Tan,Ning Sui,Qinghui Liu,Zhihui Kang,Lin Wang,Wenquan Wang,Qiang Zhou,Hanzhuang Zhang,Yinghui Wang
Low-toxicity zinc blende Mn–CuInS (MCIS) thin films and a corresponding optical switch were fabricated and examined using multiple measurements. Transient absorption spectroscopy indicated that multiple carrier processes occurred during carrier relaxation. The optical switch devices showed good responsivity and stability. The kinetics of the photo-generated charge carriers were affected by carrier concentration and showed no electric-field dependence. These prepared devices showed potential for rapid photodetection applications.
研究领域:
材料科学
·
光学工程
·
半导体物理
✓ 已验证
产品关联
DOI
高影响因子
Analytical Methods
·
2013
·Vol. 5
·期 21
·6094-6099
·
IF 1.855
Jing Ma,Fang Wang,Meng Fan,Tianyi Wang,Wei Bian,Shaomin Shuang
The room temperature phosphorescence (RTP) of quantum dots (QDs) offers many advantages compared with fluorescence, such as a longer emission lifetime, wider gap between excitation and emission spectra and minimal interference. Hence, the RTP properties of QDs and their potential for phosphorescence detection have drawn more and more attention. In this paper, N-acetyl-L-cysteine (NAC)-capped Mn-doped ZnS QDs were synthesized by a hydrothermal method. The QDs displayed a strong phosphorescence emission peak at 590 nm upon excitation at 315 nm. Because their RTP was efficiently quenched by hydrochlorothiazide (HCT), a novel RTP method for determination of HCT was developed. The results showed that under the optimized conditions, the changes of RTP intensity showed a good linear relationship with the concentration of HCT in the range of 2.5 to 95 μM, with a limit of detection of 1.25 μM and relative standard deviation of 0.44%. The related theories preliminarily demonstrated the dynamic quenching mechanism. In addition, this method was successfully applied to the analysis of practical samples. The recovery of spiked solutions ranged from 94–104%.
研究领域:
分析化学
·
材料科学
✓ 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）