Nanoscale
·
2019
·Vol. 11
·期 13
·6182-6191
·
IF 6.97
Jinjin Ma,Qianting Yao,John A. McLeod,Lo-Yueh Chang,Chih-Wen Pao,Jiatang Chen,Tsun-Kong Sham,Lijia Liu
Inorganic lead halide perovskite CsPbX3 (X = Cl, Br, or I) nanocrystals are promising candidate materials for light-emitting devices and optoelectronics. Mn-Doped CsPbX3 is of particular interest, as the Mn-doping introduces an additional emission band, making this material a promising white-light emitter. In this study, Mn-doped CsPb(Br/Cl)3 nanocrystals are prepared at room-temperature and ambient pressure. The chemical environment of Mn, and the luminescence of these nanocrystals are analyzed in detail using X-ray diffraction (XRD), extended X-ray absorption fine structure (EXAFS), X-ray absorption near-edge structure (XANES) and X-ray excited optical luminescence (XEOL). Although the introduction of Mn does not alter the long-range order of the CsPbX3 crystal, it leads to a local lattice contraction with the bond length of Mn–X much shorter than Pb–X. We also find excitation energy-dependence in both the intensity and wavelength of the perovskite excitonic emission band, while only in intensity of the Mn emission band. Detailed fitting of the XEOL reveals that the perovskite emission band is dual-channel, and it is the excitation energy-dependent intensity variation of these two channels that drives the observed red-shift of the combined emission band. Our findings also confirm that the Mn emission band is driven by exciton-Mn energy transfer and clarify the Mn chemical environment and the luminescence mechanism in Mn-doped CsPb(Br/Cl)3 nanocrystals.
研究领域:
材料科学
·
光电子学
·
纳米技术
·
固体物理
✓ 已验证
DOI
高影响因子
JOURNAL OF INDUSTRIAL AND ENGINEERING CHEMISTRY
·
2013
·
IF 2.145
Wei-guo Pan,Jie-nan Hong,Rui-tang Guo,Wen-long Zhen,Hong-lei Ding,Qiang Jin,Cheng-gang Ding,Shi-yi Guo
MnO x –CuO x /TiO 2 and MnO x –CuO x /Al 2 O 3 catalysts were prepared by sol–gel method and used for low temperature selective catalytic reduction of NO with NH 3 . The results showed that MnO x –CuO x /TiO 2 had better catalytic activity and SO 2 resistance than MnO x –CuO x /Al 2 O 3 in the temperature range of 100–250 °C. The properties of the catalysts were characterized by using XRD, N 2 adsorption, temperature programmed reduction (H 2 -TPR) and temperature programmed desorption (NH 3 -TPD). It was found that the support has a great impact on the acidity of catalyst; TiO 2 and Al 2 O 3 can promote the formation of Lewis acid sites and Brönsted acid sites respectively.
研究领域:
环境科学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2013
·
IF 2.112
Qiu-Hang Chen,Jie Zhang,Guo-Ping Chen,Rui-Qian Guo
Spindle-liked ZnSe and Mn:ZnSe quantum dots (QDs) were formed via an optimized greener approach, which may be attributed to the amine ligands adhering asymmetrically to the crystal facets. Powder X-ray diffraction (XRD) patterns revealed that the ZnSe and Mn:ZnSe QDs have a zinc blende cubic crystal structure. The crystallite size of ZnSe was calculated to be about 4 nm from the (1 1 1) peak width using the Scherrer equation, which was in agreement with the HRTEM findings. The fluorescence emission peak of as-prepared ZnSe and Mn:ZnSe QDs was 431 nm and 580 nm respectively. We investigated the effect of the reaction temperature, reflux time, precursor solvent, size of MnSe core and overcoating temperature of ZnSe layer on the optical properties of ZnSe and Mn:ZnSe QDs. It is shown that the precursor solvent plays a key role in the formation of the magic-sized QDs (MSQDs). And as a result, doped quantum dots (d-dots) showed a large Stokes shift and enhanced photoluminescence, and smaller size of the MnSe core and suitable overcoating temperature of ZnSe shell were identified as two key parameters for obtaining the high quality d-dots.
研究领域:
材料科学
·
光学
✓ 已验证
DOI
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.
研究领域:
催化化学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2022
·
IF 9.136
Lijun Niu,Lili An,Kaiting Zhang,Qian Chen,Xin Yu,Menglu Zhang,Mingbao Feng
The increased release of various emerging organic contaminants into natural waters has posed great threats to ecological safety and public health. The ensuing global water contamination has necessitated the development of highly efficient treatment strategies for water purification . Herein, we presented for the first time that the combined utilization of permanganate (Mn(VII)) and periodate (PI) could synergistically and rapidly accomplish complete destruction of different organic micropollutants (e.g., bisphenol F, methotrexate, and tetracycline) within 2–5 min. Comparatively, the single treatment only eliminated very small amounts of micropollutants. Mechanistic investigations were performed using the trapper-based electron spin resonance , scavenging and probe experiments, UV–vis spectra analysis, determination of iodine species, and multiple validation tests. These data collectively suggested that the highly reactive Mn(V)/Mn(VI) intermediates played the leading role in accelerating contaminant abatement within the Mn(VII)/PI oxidation system. Reactive oxygen/or iodine species ( 1 O 2 , OH, O 2 - , IO 3 , and IO 4 ) and low valence Mn species (Mn(II), Mn(III), and in-situ formed MnO 2 colloids) did not participate in decontamination in this process. Subsequently, the oxidized products of three micropollutants were determined, and the transformation pathways were clarified. Ring-opening, C-C bond cleavage, demethylation, carbonylation , and hydroxylation reactions mainly occurred in the degradation process. Notably, the combined system did not yield any toxic iodinated end products. Finally, the environmental risks of the degradation products were also evaluated based on in silico QSAR-based prediction tools. Overall, this study provides a novel, highly efficient, and green treatment technology, i.e., Mn(VII)/PI system, which could be employed for rapid and sustainable water decontamination.
研究领域:
环境科学
·
水处理
·
化学工程
·
污染控制
✓ 已验证
产品关联
DOI
高影响因子
APPLIED ORGANOMETALLIC CHEMISTRY
·
2025
·Vol. 39
·期 5
·e70141
·
IF 0
Huan Zhang,Wen-Qi Jin,Peng Li,Wei Gao,Xiu-Mei Zhang
A highly efficient photocatalyst, the CdS/Mn-MOF composite, was synthesized by first preparing a new 2D Mn-MOF (Mn(L)·H 2 O, H 2 L = 5-(2-benzothiazolyl)isophthalic acid) precursor through the solvothermal method and subsequently growing CdS nanoparticles. X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), UV–vis spectroscopy, and other techniques were utilized to characterize the structural, morphological, textural, compositional, and optical properties of the composites. The prepared photocatalysts, designated as X-CdS/Mn-MOF (where X = 50, 25, and 10, represents the mass percentage of CdS), were tested for photocatalytic performance. Among them, the 50-CdS/Mn-MOF sample exhibits the optimized degradation efficiency of 99.1% for Rhodamine B (RhB, 20 mg/L) in 50 min under visible light irradiation, which is 7.3 times and 2.4 times higher than that of Mn-MOF and CdS, respectively. Various test results indicate that the improved photocatalytic activity of CdS/Mn-MOF composites can be attributed to the formation of heterojunctions. Specifically, the heterojunctions enhance the separation efficiency of photogenerated carriers and effectively suppress the recombination of electrons and holes, thereby improving the overall efficiency of the photocatalytic reaction. Moreover, the presence of heterojunctions optimizes the material's band structure, facilitating more efficient carrier transport, which further enhances photodegradation performance. Radical quenching experiments confirmed hydroxyl radicals (·OH − ) and superoxide radical anions (·O 2 − ) played dominant roles in the photodegradation process. Additionally, the composite material also demonstrates good stability and reproducibility. The research further provides evidence that the efficiency of dye degradation can be significantly improved by the rational design of composite catalysts consisting of other semiconductors and MOFs.
研究领域:
材料科学
·
环境科学
✓ 已验证
DOI
CRYSTENGCOMM
·
2012
·Vol. 14
·期 24
·8440-8445
·
IF 3.842
Tingting Yao,Shufang Kou,Yanghui Sun,Qing Zhao,Jian Yang
Transition-metal doping in semiconductors is an important way to modulate their intrinsic properties or bring out new functionalities for applications. Here, elongated Mn-doped ZnSe1−xSx nanocrystals are synthesized through a facile one-pot reaction under mild conditions. These ZnSe1−xSx nanocrystals with a diameter of 2–4 nm have a cubic phase structure. EPR and PL spectra confirm the successful doping of Mn2+ into the ZnSe1−xSx nanocrystals, based on the corresponding hyperfine splitting constants and emission bands. The temporal evolution of UV-vis absorption and PL spectra indicates the growth-doping mechanism for the formation of the doped nanocrystals. Surface coating of these nanocrystals with a shell increases the quantum yield up to 35%. And the dual-function role of 1-dodecanethiol is confirmed in the formation of the elongated Mn-doped ZnSe1−xSx nanocrystals.
研究领域:
材料科学
·
光学
✓ 已验证
DOI
高影响因子
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
·
2021
·Vol. 104
·期 11
·5547-5556
·
IF 3.784
Jian Guo,Jianguo Chen,Jinrong Cheng,Qi Tan
Lead-free 0.75BiFeO 3 –0.25BaTiO 3 (0.75BF–0.25BT) ceramics have been extensively studied because of their high Curie temperature. The aging behavior and thermal stability of piezoceramics play decisive roles in their device applications. In this work, effects of Mn doping on the phase structure, aging behavior, and thermal stability of 0.75BF–0.25BT ceramics were characterized and related mechanisms were investigated. With the increase in Mn content, the typical rhombohedral phase of 0.75BF–0.25BT ceramics changed to the coexistence of pseudo-cubic and rhombohedral phases. Mn modification enhanced the aging behavior and thermal stability of ceramics obviously. The aging rates of d 33 and k p for 0.75BF-0.25BT ceramics with 1.0 mol% Mn are 1.3% and 1.1%, respectively, which are only 1/4 those values for the undoped ceramics. The variation of ε r of 0.75BF-0.25BT ceramics with 1.0 mol% Mn is half of undoped ceramics under 500℃. The depoling temperature of 0.75BF-0.25BT ceramics with 1.0 mol% Mn was 450℃, which is about 200℃ higher than that of undoped ceramics. The enhanced aging behavior results from the decreased defect concentrations, and the better thermal stability is owing to the significantly improved poling state due to the enhanced resistivity, large grain size, and decreased crystal distortion by Mn modification. These results reflect that a proper amount of Mn doping is an effective way to enhance the aging behavior and electric thermal stability.
研究领域:
材料科学
·
电子工程
✓ 已验证
产品关联
DOI
高影响因子
Nanomaterials
·
2019
·Vol. 9
·期 11
·1520
·
IF 4.034
Lei Qiu,Jiaxiong Xu,Xiao Tian
Ag and Mn dopants were incorporated into Cu2ZnSnS4thin film to reduce defects in thin film and improve thin film properties. Sol–gel and spin-coating techniques were employed to deposit Ag and Mn co-doped Cu2ZnSnS4thin films. The structures, compositions, morphologies, and optical properties of the co-doped thin films were characterized. The experimental results indicate the formation of kesterite structure without Ag and Mn secondary phases. The amount of Ag in the thin films is close to that in the sols. The co-doped Cu2ZnSnS4thin films have an absorption coefficient of larger than 1.3 × 104cm−1, a direct optical band gap of 1.54–2.14 eV, and enhanced photoluminescence. The nonradiative recombination in Cu2ZnSnS4thin film is reduced by Ag and Mn co-doping. The experimental results show that Ag and Mn incorporation can improve the properties of Cu2ZnSnS4thin film.Keywords:Cu2ZnSnS4;Ag and Mn co-doping;thin films;sol–gel preparation
研究领域:
材料科学
·
半导体物理
·
光电
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Environmental Chemical Engineering
·
2024
·
IF 7.4
Peng Zhao,Jingwei Liu,Wei Zhu,Jie Meng,Zhuang Li,Jinwei Qin,Xiaohui Wang,Haiqin Wan,Chao Yao,Lin Dong
Catalytic combustion is one of effective ways to remove short-chain alkanes. In this study, we elaborately designed a novel catalyst of in situ Co-Mn decorated LaMnO 3 perovskite for ethane catalytic combustion, in which extra Mn and Co species were introduced via acidic KMnO 4 and Co(NO 3 ) 2 solution precipitation method. The addition of Mn and Co could not only slightly etch LaMnO 3 , thereby increasing specific surface area and redox property, but also generate new active phase CoMn 2 O 4 , thus accelerating reaction. Among all the as-prepared catalysts, CMO/LMO-0.5 exhibited admirable ethane removal efficiency with a T 90 of 365 °C, a reaction rate of 0.46 mmol·g −1 ·h −1 , a TOF value of 0.64 mmol·g −1 ·h −1 , and excellent hydrothermal stability and reusability. Moreover, according to in situ DRIFTS, a possible pathway was proposed. This work can rationalize an alternative approach to develop an active catalyst for short-chain alkanes catalytic combustion or other catalytic systems.
研究领域:
催化化学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
WATER RESEARCH
·
2023
·
IF 12.8
Xuecong Qian,Shilong Wang,Haijun Cheng,Ziye Jia,Da Wang,Yandong Xie,Jinhao Duan,Yu Tian,Jun Ma
The oxidation kinetics of Mn(II) by free chlorine is relatively low under near-neutral pH conditions which limits the Mn removal efficiency in drinking water treatment. Therefore, this study investigated the oxidation efficiency of Mn(II) by the UV-enhanced chlorination (UV/chlorine) system and identified the responsible reactive radical species. The results show that the oxidation kinetic of Mn(II) was greatly enhanced by the UV/chlorine system under near-neutral pH or even acidic conditions. The pseudo-first-order reaction rate of Mn(II) at pH 8.0 (within the first 20 min) increased from 2.60 × 10 −5 s −1 to 3.41 × 10 −4 s −1 . Based on the scavenging experiments and the steady-state kinetic modeling, ClO · and ClO 2 , whose steady-state concentration (∼10 −10 M and ∼10 −9 M, respectively at pH 8.0) was at least 4 orders of magnitude higher than that of HO · and Cl · , were recognized as the dominant reactive species contributing to the oxidation of Mn(II). Kinetic model calculations indicate that the contribution of ClO · to the oxidation of Mn(II) was consistently maintained above 70 %, and ClO 2 also played an important role in the oxidation of Mn(II) especially under acidic and alkaline conditions. In addition, the background components of HCO 3 − and Cl − had negligible influence on the oxidation efficiency because they barely changed the concentration of the ClO · and ClO 2 . This study first demonstrates the important role of ClO 2 in the oxidation of Mn(II) in the UV/chlorine system, and the possible role of ClO 2 in the degradation of some organic pollutants needs to be carefully evaluated in the future.
研究领域:
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2023
·Vol. 34
·期 19
·1-13
·
IF 2.8
Hu Lifang,Yang Kun,Liu Xijing,Zhu Jichao,He Jie,Chen Xiaoyang
Semiconductor photocatalysis is a green and environmentally friendly antibiotic wastewater treatment technology without secondary pollution. In this paper, a series of montmorillonite (MMT) samples loaded with Cu, Mn, and Ni were prepared by impregnation method. The structure and spectral response of the as-prepared samples were characterized by powder X-ray diffraction, energy-dispersive spectroscopy, laser Raman spectroscopy, X-ray photoelectron spectroscopy, ultraviolet photoelectron spectroscopy, UV–Vis diffuse reflectance spectroscopy (UV–Vis DRS), electrochemical impedance spectroscopy, and photocurrent response test. The photocatalytic degradation of tetracycline hydrochloride (TCH) was carried out under simulated solar irradiation, and the photocatalytic properties of MMT samples with different loads were investigated. The characterization results show that Cu and Mn have strong interaction with MMT, and composite photocatalyst Cu 10 Mn 10 -MMT has the smallest Nyquist arc and higher photocurrent intensity. Degradation experiments on TCH showed that Cu 10 Mn 10 -MMT had the best photocatalytic degradation, with a degradation rate of 79.78%, three times that of the original MMT. Active substances capture experiments showed that h + and O 2 . − were the main active substances for the degradation of TCH by Cu 10 Mn 10 -MMT. After the combination of Cu, Mn, and MMT, the band structure changed, resulting in more h + and O 2 .− involved in the redox reaction, thereby improving the photocatalytic degradation performance of TCH. In this work, a promising photocatalyst is used to efficiently and greenly degrade antibiotic 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
危险品化学品经营许可证（带存储）