JOURNAL OF ALLOYS AND COMPOUNDS
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2019
·
IF 4.175
Yurong Ren,Xiaofang Lai,Minhao Guo,Ruiqi Wang,Jun Deng,Jikang Jian
Three layered quaternary sulfides, NaLi M S 2 ( M = Mn, Fe, Co) were synthesized by solid-state reactions. They adopt a trigonal CaAl 2 Si 2 -type structure (S.G. P -3 m 1) with Li and M randomly distributed at the tetrahedral metal site. Magnetic measurements reveal spin-glass ground states for these compounds, in contrast to the long-range antiferromagnetic order in the ternary counterpart NaFe 1.6 S 2 . As evidenced by electrical resistivity and optical measurements , all these three compounds show semiconducting nature, consistent with the results of first-principles calculations. The measured band gaps are 3.4 eV and 1.25 eV for NaLiMnS 2 and NaLiCoS 2 , respectively. Photoelectric measurements on NaLiCoS 2 demonstrate its potential application in photovoltaic devices .
研究领域:
材料科学
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固体化学
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凝聚态物理
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无机化学
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功能材料
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高影响因子
CHEMICAL ENGINEERING & TECHNOLOGY
·
2015
·Vol. 38
·期 2
·291-296
·
IF 2.442
Chen Zhou,Yexin Zhang,Lingjun Hu,Hongfeng Yin,Wei Guo Wang
Mn-doped La 0.8 Sr 0.2 CoO 3 perovskite oxides (La 0.8 Sr 0.2 Co 1– x Mn x O 3 ; x = 0, 0.1, 0.3, 0.5) were synthesized by a modified sol-gel method. The phase-pure oxides were obtained. CoO and carbonates were formed on the surface of La 0.8 Sr 0.2 CoO 3 . With increasing doping content, these impurities were reduced while the stability of the perovskite structure was improved. The valence state of B-site ions and the amount of absorbed oxygen were influenced by Mn doping. The catalytic activity of the perovskite catalysts was investigated for CO oxidation and simultaneous removal of CO, C 3 H 8 , and NO. For CO and NO removal, La 0.8 Sr 0.2 Co 0.9 Mn 0.1 O 3 exhibited the best performance. For C 3 H 8 removal, the reactivity was promoted linearly with the doping content. The structure-activity relationship is also discussed.
研究领域:
材料科学
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催化化学
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Sustainable Energy & Fuels
·
2024
·Vol. 8
·期 23
·5524-5534
·
IF 5
Yihong Zhu,Juping Zhang,Dongfang Li,Tao Zhu,Xing Zhu
Chemical looping dry reforming of methane (CL-DRM) is an efficient pathway for the conversion of methane and CO2 into synthesis gas ready for the Fischer–Tropsch process, which largely depends on the redox behavior of oxygen carriers. Perovskite-structured metal oxides are promising candidates for CL-DRM due to the structural diversity brought about by elemental doping. Herein, we proposed to fabricate a highly active oxygen carrier via functionally designed Mn-based perovskite oxides via polymetallic doping. Cu-doping in the B-site of SrMnO3−δ reveals a significant anti-coking effect in the high-temperature continuous CH4/CO2 redox process. Ni-doping in the B-site boosts the performance of methane activation resulting in high methane conversion. Moreover, Ce-doping in the A-site elevates oxygen migration and enhances partial oxidation of methane to H2 and CO as well as the re-oxidation of reduced perovskite oxides. Considering the roles of Cu, Ni and Ce doping of SrMnO3−δ, a polymetallic-doped perovskite of Sr0.8Ce0.2Mn0.7Cu0.1Ni0.2O3−δ was synthesized and evaluated in CL-DRM. The optimized perovskite oxide demonstrated exceptional performance with a methane conversion of 85% and a CO selectivity of 93% throughout 30 redox cycles at 850 °C. In the redox reactions, the transition metals of Mn, Cu, and Ni agglomerated during the reduction but could return to a well-dispersed state after re-oxidization with CO2. The perovskite oxide exhibits self-structural-regenerability and the nano-scale agglomeration–dispersion cycle ensures the high structural stability of the material in the successive CL-DRM cycles. This study provides an important insight into the regulation of catalytic activity, oxygen mobility and carbon-resistance via doping of perovskite oxides with various kinds of compatible elements in both A and B sites.
研究领域:
材料科学
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催化化学
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能源工程
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化学工程
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可持续化学
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高影响因子
Catalysts
·
2022
·Vol. 12
·期 12
·1606
·
IF 4.501
Ruicheng Li,Jianhua Xiong,Yuanyuan Zhang,Shuangfei Wang,Hongxiang Zhu,Lihai Lu
In this study, a Co-Mn/CeO2composite was prepared through a facile sol-gel method and used as an efficient catalyst for the ozonation of norfloxacin (NOR). The Co-Mn/CeO2composite was characterized via XRD, SEM, BET and XPS analysis. The catalytic ozonation of NOR by Co-Mn/CeO2under different conditions was systematically investigated, including the effect of the initial solution’s pH, Co-Mn/CeO2composite dose, O3dose and NOR concentration on degradation kinetics. Only about 3.33% of total organic carbon (TOC) and 72.17% of NOR could be removed within 150 min by single ozonation under the conditions of 60 mg/L of NOR and 200 mL/min of O3at pH= 7 and room temperature, whereas in the presence of 0.60 g/L of the Co-Mn/CeO2composite under the same conditions, 87.24% NOR removal was obtained through the catalytic ozonation process. The results showed that catalytic ozonation with the Co-Mn/CeO2composite could effectively enhance the degradation and mineralization of NOR compared to a single ozonation system alone. The catalytic performance of CeO2was significantly improved by the modification with Mn and Co. Co-Mn/CeO2represents a promising way to prepare efficient catalysts for the catalytic ozonation of organic polluted water. The removal efficiency of NOR in five cycles indicates that Co-Mn/CeO2is stable and recyclable for catalytic ozonation in water treatment.Keywords:antibiotics;catalytic ozonation;emerging contaminant;Co-Mn/CeO2;norfloxacin
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高影响因子
Processes
·
2022
·Vol. 10
·期 12
·2562
·
IF 3.352
Yuxi Gao,Baofang Jin,Xiaodong Wu,Zhenguo Li,Rui Ran,Duan Weng
Two Mn0.15Ce0.85O2−δmixed oxides were synthesized by a co-precipitation method using Mn(NO3)2and KMnO4as the manganese precursors, respectively. Structural analyses by X-ray powder diffraction and Raman spectroscopy reveal the formation of MnOx-CeO2solid solutions. The Mn0.15Ce0.85O2−δcatalyst prepared from the high-valent manganese precursor exhibits higher activity for the catalytic oxidation of NO. The advantage of KMnO4is related to the improved redox property of the catalyst as supported by H2temperature-programmed reduction (TPR) and O2temperature-programmed desorption (TPD). The Mn-Ce interactions create more Mn4+, Ce3+and oxygen vacancies on the KMnO4-synthesized mixed oxides based on the Raman and X-ray photoelectron spectra (XPS).Keywords:solid solutions;precursor;oxidation state;lattice defects;NO oxidation
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Journal of Environmental Chemical Engineering
·
2023
·
IF 7.7
Qian Wang,Can He,Yue Shan,Zhongguo Zhang,Jiuyi Li
The aim of this study is to investigate the degradation efficiency and mechanism of atenolol (ATL) by catalytic ozonation with Al 2 O 3 supported manganese-cerium mixed oxides (Mn-Ce@Al 2 O 3 ), prepared by the impregnation-calcination method. The Mn-Ce@Al 2 O 3 with 0.2 wt% manganese and 0.2 wt% cerium exhibited superior catalytic performance, resulting in complete ATL degradation and 63% mineralization. Mn-Ce solid solution on the surface significantly increased the specific surface area (279.5 m 2 /g). High amount of Ce 3+ , Mn 3+ and high density of surface-active oxygen were contained on the surface of the catalyst, which facilitates the formation of oxygen vacancies and promotes the electron transfer in the catalyst. Combined with the low charge transfer resistance, surface protonated hydroxyl group, which was the active site of 0.2Mn-Ce@Al 2 O 3 , was more likely to adsorb ozone and decompose it into reactive oxygen species . O 2 · − and •OH were found to be the dominant active radicals for ATL degradation and mineralization that followed first-order kinetics. 17 intermediates were identified and 3 main degradation pathways were summarized, in order to provide reference for the complete mineralization of ATL.
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高影响因子
Journal of Physical Chemistry C
·
2023
·
IF 3.7
Liang Jing,Qingmei Cen,Qi Pang,Jin Zhong Zhang
In this work, lead-free zero-dimensional (0D) all-inorganic perovskite Mn2+-doped Cs2InCl5·H2O microcrystals (MCs) with introduced Bi3+ ion were synthesized by supersaturation recrystallization at room temperature. The electronic bandgap of the MCs is tuned from ∼5.1 to ∼3.1 eV, and the electronic absorption is enhanced in the 200–400 nm region by Bi3+ incorporation. Upon excitation at 365 nm, the MCs with introduced Bi3+ exhibit strong red emission peaking at 640 nm, which is attributed to the Mn2+ transition (4T1g → 6A1g). Simultaneous Mn2+ and Bi3+ incorporation into Cs2InCl5·H2O shows 60 times enhancement of the 640 nm emission band compared to Mn2+ alone. This PL enhancement is attributed to the energy transfer (ET) from the [BiCl6]3– octahedron, which acts as a UV light absorber and exciton donor, to [MnCl6]4–. In addition, a yellow-light-emitting diode (LED) device based on the Cs2In0.45Bi0.55Cl5·H2O:17%Mn MCs was fabricated and evaluated, showing high color saturation at a drive current of 420 mA and good stability. This study demonstrates a new method for achieving efficient red emission by incorporating ns2 metal ions and Mn ions in 0D lead-free metal halides.
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高影响因子
CATALYSIS COMMUNICATIONS
·
2022
·
IF 3.51
Haoxuan Wei,Jujiao Zhao,Md. Hasibur Rahaman,Quanfeng Wang,Jun Zhai
In this study, the catalytic activity of soluble Mn(III) ions, soluble Mn(III)-pyrophosphate (PP), and solid Mn(III) (α-MnO 2 ) towards peroxymonosulfate (PMS) activation was investigated through carbamazepine (CBZ) degradation. The degradation efficiency of CBZ was negligible when soluble Mn(III) ions or Mn(III)-PP were used as catalysts, while 99.7% of CBZ was degraded in the α-MnO 2 /PMS system with no soluble Mn(III) ions detected. The degradation efficiency of CBZ reduced by 18% with the solid Mn(III) content decreasing. Hence, the solid Mn(III) made the major contribution to PMS activation. This study supported a better understanding of the role of Mn(III) in PMS activation.
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高影响因子
FUEL
·
2022
·
IF 8.035
Mingqiang Chen,Wei Dai,Yishuang Wang,Zhiyuan Tang,Hong Li,Chang Li,Zhonglian Yang,Jun Wang
Lignin catalytic depolymerization (LCD) into liquid fuels and aromatic chemicals in supercritical ethanol systems is one of the most effective strategies for efficient utilization of biomass resources. In this study, a series of sepiolite (SEP) supported Mo-Mn catalysts with different Mn/Mo ratios were prepared and applied to LCD. Experimental results for lignin and 2-phenoxy-1-phenyl ethanol (PP) confirmed that Mo/Mn species promoted the breakage of β-O-4 bonds, Mn additive effectively inhibited the alkylation of intermediates, and Mn/Mo ratios distinctly affected the yields of lignin oil (LO) and guaiacols. All as-prepared Mn-Mo/SEP catalysts achieved approximately 100 % conversions of lignin and PP. Various characterization results demonstrated that Mn/Mo ratios could regulate the particle sizes of metal oxides as well as the concentration of oxygen vacancies (O V ) and surface acidic sites. In 3Mn1Mo/SEP, the appropriate interaction among SEP , Mn and Mo species reduced the particle sizes of metal oxides and rendered the crystalline phase structure in a relatively complex state, which undoubtedly generated massive steps/corners on its surface and then enhanced the hydrogenation reaction. Furthermore, the 3Mn1Mo/SEP contained many O V and suitable distribution of Lewis and Brønsted acid sites, which facilitated the adsorption of oxygen-containing intermediates and further hydrogenation and deoxygenation. Therefore, 3Mn1Mo/SEP achieved 45.7 % of LO yield with an HHV of 32.31 MJ/Kg and the highest selectivity to phenols (85.61 %) and yield of guaiacols (308.9 mg/g lignin). In addition, the plausible reaction network for LCD was proposed based on the results of experiments and characterizations.
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高影响因子
ENVIRONMENTAL RESEARCH
·
2022
·
IF 8.431
Yajie Guo,Xinyu Zhang,Dandan Zhang,Shunlin Li,Hui Wang,Yiyin Peng,Zhaoyong Bian
The present work demonstrates a simple one-step pyrolysis method for the synthesis of a catalytic sludge-based carbon (SBC) biochar containing Fe and Mn from dehydrated sludge with added KMnO 4 and Fe(II). The electrocatalytic degradation of triclosan (TCS) in water was evaluated using an Fe/Mn-SBC cathode to promote a heterogeneous Fenton-like reaction. The catalyst generated at 500 °C exhibited an abundant porous structure and a relatively high surface area, and produced an electrode with better conductivity and electron diffusion . The presence of metal oxides changed the surface structure defects of this biochar and enhanced its catalytic performance while increasing the electrochemically active surface area by 72.68 mF/cm 2 compared with plain SBC. TCS was degraded (91.3%) within 180 min by oxygen species generated in situ on an Fe/Mn-SBC cathode because the activation energy for oxygen reduction was lowered by 4.62 kJ/mol. The degradation of TCS followed pseudo first-order kinetics and was controlled by TCS diffusion and interfacial chemical reactions between adsorbed TCS and the electrode. Possible TCS degradation pathways were devised based on the main intermediates, and 1 O 2 was found to be more important than •OH radicals. Through toxicity test and prediction, the toxicity of degradation was gradually reduced. This study demonstrates a simple and ecofriendly method for the electrocatalytic degradation of organic pollutants.
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DOI
PubMed
高影响因子
NANOTECHNOLOGY
·
2022
·Vol. 33
·期 45
·455703
·
IF 3.953
Lei Wang,Hengbin Mao,Junhui Li,Yi Li,Mingliang Li,Jinpeng Zhu,Bingbing Fan,Wen Liu,Gang Shao,Hongliang Xu,Hailong Wang,Rui Zhang,Hongxia Lu
CsPbX3 (X = Cl, Br, I) semiconductor nanocrystals (NCs) have excellent optical and photoelectric properties, and are potential core materials for various photoelectric devices. However, the toxicity of Pb and instability have been the key limitations to application of NCs. Herein, using MnBr2 and MnBr2·4H2O as manganese sources, heavy Mn-doped CsPbBr3 (Mn:CsPbBr3) NCs are synthesized by high-energy ball grinding, which avoids high temperature, a large number of polar solvents and atmosphere protection required in traditional liquid phase methods. However, when MnBr2·4H2O is used as the raw material, infinite solid solution doping can be achieved, and the synthesized Mn:CsPbBr3 NCs show smaller particle size, stronger PL intensity and stability. The reason is that presence of crystal water plays a similar role to wet milling in the ball milling process, and can promote the passivation effect of oleylamine (OAm) on nanocrystal defects and the connection between them. In addition, a simple, easy-operating and beneficial to commercial production method for the preparation of Mn:CsPbBr3 NCs/EVA flexible films is proposed, which can effectively improve the stability of Mn:CsPbBr3 NCs. This study is expected to provide an effective way for the synthesis and stability improvement of CsPbX3 NCs doped with different ions.
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DOI
PubMed
高影响因子
International Journal of Environmental Research and Public Health
·
2022
·Vol. 19
·期 15
·9437
·
IF 4.614
Qianli Guo,Xianhu Qi,Jian Zhang,Bo Sun
Aqueous complexes of Mn(III) ion with ligands exist in various aquatic systems and many stages of water treatment works, while HSO3−is a common reductant in water treatment. This study discloses that their encounter results in a process that oxidizes organic contaminants rapidly. Pyrophosphate (PP, a nonredox active ligand) was used to prepare the Mn(III) solution. An approximate 71% removal of carbamazepine (CBZ) was achieved by the Mn(III)/HSO3−process at pH 7.0 within 20 s, while negligible CBZ was degraded by Mn(III) or HSO3−alone. The reactive species responsible for pollutant abatement in the Mn(III)/HSO3−process were SO4•−and HO•. The treatment efficiency of the Mn(III)/HSO3−process is highly related to the dosage of HSO3−because HSO3−acted as both the radical scavenger and precursor. The reaction of Mn(III) with HSO3−follows second-order reaction kinetics and the second-order rate constants ranged from 7.5 × 103to 17 M−1s−1under the reaction conditions of this study, suggesting that the Mn(III)/HSO3−process is an effective process for producing SO4•−. The pH and PP:Mn(III) ratio affect the reactivity of Mn(III) towards HSO3−. The water background constituents, such as Cl−and dissolved organic matter, induce considerable loss of the treatment efficiency in different ways.Keywords:Mn(III);bisulfite;advanced oxidation processes;sulfate radical;micropollutant abatement
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高影响因子
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