ANALYTICA CHIMICA ACTA
·
2022
·
IF 6.911
Xue Wang,Futing Wen,Liu He,Jiangyu Su,Ping Jiang,Daiping He
Defects engineering as an effective strategy was widely utilized to modulate catalytic performance for heterogeneous catalysts through tuning surface electronic surface and creating more active sites. In this work, porous Co–Mn oxide nanosheets with abundant oxygen vacancies (OVs-CMO NSs) were prepared via a simple “one-stone-two-birds” method. OVs were verified by various characterizations and found more favorable for O 2 absorption and activation to produce more reactive O2•- radical, resulting in an improved oxidase-like activity in initiating 3,3′,5,5′-tetramethylbenzidine (TMB) oxidation , with a lower K m value of 0.00717 mM and a higher V max of 2.086 × 10 −7 M/s. Since heparin (Hep) shows an inhibition effect on OVs-CMO NSs-TMB chromogenic system due to strong absorption, a colorimetric sensing platform for Hep detection was established. The present colorimetric detection shows high sensitivity, good selectivity and reliability for normal goat serum. This work not only provides a high-performance non-precious metal oxidase mimic prepared by simple surface defect engineering, but also builds a sensitive colorimetric method for Hep detection.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2023
·
IF 15.1
Kang-Hui Hu,Chao-Qiong Zhu,Bao-Ping Zheng,Lang Qiu,Fang Wan,Yang Song,Ben-He Zhong,Zhen-Guo Wu,Xiao-Dong Guo
Li-rich Mn-based oxide cathodes are one of the most promising cathode candidates for high energy density over 400 Wh kg −1 , deriving from oxygen redox of Li-O-Li configuration. However, the deep oxygen oxidation would lead to the formation of peroxides and superoxides (O 2 n − , 0 < n ≤ 2) and even oxygen (O 2 ), accompanied by crystal phase transformation and structure collapse. Herein, an integrative strategy of simultaneously regulating the right amount of oxygen vacancies (OVs) and B-atom doping is proposed to achieve differentially modification of both R-3 m and C2/m phases. Firstly, Rietveld refinement, HRTEM and in situ XRD results reveal that the linear increase of OVs content is achieved by regulating the amount of BN and the selective introduction of OVs inside the C2/m phase makes the oxygen partial pressure lower in the weak O-Li-O bonds of TM-layer and inhibits oxygen release at over 4.5 V. Meanwhile, kinetics test shows oxygen defects would accelerate the Li + diffusion and reduce the electronic impedance driven by uneven local charge distribution. Secondly, lattice analysis shows the strong covalent B-O bonds located at the tetrahedral site not only prevent the overoxidation of the oxygen atoms at high voltage, but also hinder the migration of Mn atoms through tetrahedral sites, which effectively avoids the damage of the crystal structure. As a result, the modified cathode exhibits the excellent discharge specific capacity of 272 mA h g −1 at 0.1C, higher rate performance of 145 mA h g −1 at 5C, an outstanding capacity retention rate of 93% at 1C and lower voltage decay value of 0.43 V after 200 cycles. This promising strategy could simultaneously achieve both high energy density and superior cycling stability and help to advance industrial application of Li-rich Mn-based Cathodes.
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2023
·
IF 22.1
Wang Song,Qianni Cheng,Li Han,Jiawei Ji,Yandi Cai,Wei Tan,Jingfang Sun,Changjin Tang,Lin Dong
Manganese oxide-based catalysts exhibit excellent low-temperature denitration efficiency, making them potential candidates for application. Herein, the relationship between reaction stability and phase structure for MnO 2 , Mn 2 O 3 and Mn 3 O 4 was disclosed. The NO conversion for Mn 2 O 3 drastically reduced after 120 h reaction, while minor decline was detected for MnO 2 and Mn 3 O 4 . Based on dedicate qualitative and quantitative analyses on the deposits over catalyst surface, deactivation trigged by ammonium nitrate (AN) deposition was confirmed. Different from penta-coordinated Mn 4+ on MnO 2 (110) and tri-coordinated Mn 2+ , penta-coordinated Mn 4+ on Mn 3 O 4 (101), the unique tetra-coordinated Mn 3+ on Mn 2 O 3 (200) could stabilize the nitrates and make it difficult to be removed via decomposition or reaction and accumulate continuously, which resulted in the significant deactivation. This research could not only unveil the poisoning mechanism of MnO x based catalysts, but also provide new insights into the relationship between the catalytic stability and surface Mn-O microstructure.
✓ 已验证
产品关联
DOI
高影响因子
Laser & Photonics Reviews
·
2023
·
IF 11
Wen Li,Yunyun Li,Ying Wang,Zhengyang Zhou,Chao Wang,Yiyang Sun,Jianyong Sheng,Jiawen Xiao,Qian Wang,Shunsuke Kurosawa,Maksym Buryi,David John,Karin Paurová,Martin Nikl,Xiaoping OuYang,Yuntao Wu
The urgency for cost-effective, high-resolution, flexible X-ray imaging detectors is generating great demand for scintillators with low-temperature processability, high scintillation yield, and negligible afterglow. X-ray imaging materials are currently dominated by inorganic scintillators in the form of rigid films and bulk crystals, which have inherent limitations including high-temperature, complex synthesis, and considerable challenges toward advanced nonplanar imaging. Here, high-performance and flexible X-ray scintillators based on novel zero-dimensional (0D) (BTPP) 2 MnX 4 (BTPP = benzyltriphenylphosphonium; X = Cl, Br) halides are reported. They emit bright green light originating from the 4 T 1 - 6 A 1 transition of Mn 2+ under X-ray excitation. In particular, (BTPP) 2 MnBr 4 single crystals exhibit excellent air- and radiation-stability, a high scintillation yield of 53 000 photons MeV −1 , a low detection limit of 89.9 nGy air s −1 , and an ultralow afterglow comparable to commercial Bi 4 Ge 3 O 12 (BGO) single crystals. Moreover, the (BTPP) 2 MnCl 4 @polydimethylsiloxane (PDMS) flexible scintillation screens achieve a high spatial resolution of 14.1 lp mm −1 and realize high-quality imaging results of nonplanar objects. This study demonstrates that the flexible scintillation screens based on low-dimensional Mn(II) hybrid halides have significant potential for low-dose and high-resolution X-ray imaging applications.
✓ 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.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2023
·
IF 13.6
Yang Zong,Hua Zhang,Hao Liu,Jun Xu,Zhengwei Zhou,Xiaomeng Zhang,Ting Zhang,Deli Wu
Mn(II) is among the most efficient catalysts for the periodate (PI)-based oxidation process . In-situ formed colloidal MnO 2 simultaneously serves as the catalyst and oxidant during the degradation of organic contaminants by PI. Here, it is revealed that the complexation of Mn(II) by ethylene diamine tetraacetic acid (EDTA) further enhances the performance of PI-based oxidation in the selective degradation of organic contaminants. As evidenced by methyl phenyl sulfoxide probing, 18 O-isotope labeling, and mass spectroscopy , EDTA complexation modulates the reaction pathway between Mn(II) and PI, triggering the generation of high-valent manganese–oxo (Mn V –oxo) as the dominant reactive species. PI mediates the single-electron oxidation of Mn(II) to Mn(III), which is stabilized by EDTA complexation and then further oxidized by PI via the oxygen-atom transfer step, ultimately producing the Mn V –oxo species. Ligands analogous to EDTA, namely, [S,S]-ethylenediaminedisuccinic acid and L -glutamic acid N , N -diacetic acid, also enhances the Mn(II)/PI process and favors Mn V –oxo as the dominant species. This study demonstrates that functional ligands can tune the efficiency and reaction pathways of Mn(II)-catalyzed peroxide and peroxyacid-based oxidation processes.
✓ 已验证
产品关联
DOI
PubMed
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.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Chemical Science
·
2021
·Vol. 12
·期 13
·4779-4788
·
IF 9.825
Yong Yang,Mehmed Z. Ertem,Lele Duan
The [fac-Mn(bpy)(CO)3Br] complex is capable of catalyzing the electrochemical reduction of CO2 to CO with high selectivity, moderate activity and large overpotential. Several attempts have been made to lower the overpotential and to enhance the catalytic activity of this complex by manipulating the second-coordination sphere of manganese and using relatively stronger acids to promote the protonation-first pathway. We report herein that the complex [fac-Mn(bpy-CONHMe)(CO)3(MeCN)]+ ([1-MeCN]+; bpy-CONHMe = N-methyl-(2,2′-bipyridine)-6-carboxamide) as a pre-catalyst could catalyze the electrochemical reduction of CO2 to CO with low overpotential and high activity and selectivity. Combined experimental and computational studies reveal that the amide NH group not only decreases the overpotential of the Mn catalyst by promoting the dimer and protonation-first pathways in the presence of H2O but also enhances the CO2 electroreduction activity by facilitating C–OH bond cleavage, making [1-MeCN]+ an efficient CO2 reduction pre-catalyst at low overpotential.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2021
·
IF 7.312
Li Li,Qian Zhang,Yuecheng She,Yongbo Yu,Junming Hong
Mn–Fe bimetal catalyst possesses excellent activation properties, and the enhancement of Mn/Fe redox cycle for electron transfer is related to the crystalline structure and surface functional groups. Therefore, material structure optimization is an effective strategy to improve its activation performance in advanced oxidation . In this study, Mn–Fe LDO catalyst with strong Mn/Fe synergistic effect was synthesized, and used for bisphenol A degradation. Under the condition of 0.4 g/L Mn-Fe LDO, 1.5 mM PMS and pH 7.0, Mn-Fe LDO/PMS system exhibited excellent degradation performance that 100% of BPA (20 mg/L) and 72.0% of COD could effective be degraded within 50 min. Five-run recycle and metal ions leaching experiments proved the excellent reusability and stability of Mn-Fe LDO. To deepen the understanding of catalytic mechanism, the synergistic effect and electron transfer between Mn and Fe were confirmed via XPS and CVs results. Moreover, the indispensable role of surface hydroxyl groups were clarified via phosphate masking experiment, ATR-FTIR and LSV analysis. The presence of Mn and Fe active sites and hydroxyl groups on Mn-Fe LDO surface could efficiently promote electron transfer, thus accelerating the redox cycles of Mn 3+ /Mn 2+ and Fe 3+ /Fe 2+ . The generation of SO 4 ·− and HO· as the main radicals was occurred on the surface of Mn-Fe LDO, and SO 4 ·− played a major role during the reaction. On the basis of these experimental conclusions, the mechanisms of Mn–Fe LDO/PMS system for high-efficiency BPA degradation were proposed. GC-MS analysis was performed to detect the BPA degradation intermediates and propose the possible degradation pathways.
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2021
·Vol. 11
·期 6
·3371-3379
·
IF 3.361
Zesheng Chen,Kun-huan He,Runzhi Wei,Yiju Lv,Zheng Liu,Guo-Cheng Han
A new metal–organic framework (MOF) compound [Mn2(2,2′-bca)2(H2O)2]n (Mn-MOFs) was successfully synthesized by solvothermal method, and Mn-MOFs@Zn material was prepared by loading zinc phosphate onto Mn-MOFs by ball milling, then Mn-MOFs@Zn was added to the water-based acrylic paint to prepare Mn-MOFs@Zn@acrylic coating. The AC impedance test results showed Mn-MOFs@Zn@acrylic coating has higher corrosion inhibition performance and stability to mild steel when compared with blank coating. The impedance modulus of the blank coating in the low frequency region decreased by 90%, and the Rct showed a trend of first increasing and then decreasing over time, the maximum Rct was only 303.8 Ω, which was only Mn-MOFs@Zn@acrylic coating one-seventh of the Rct value. The artificial scratch experiment showed that the Mn-MOFs@Zn@acrylic coating only slightly corrodes at the scratches, because Mn-MOFs@Zn material made the coating a self-repairing function and improved the durable anticorrosion performance of the acrylic coating.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2020
·
IF 9.038
Wei Ding,Huaili Zheng,Yongjun Sun,Zhiwei Zhao,Xinyu Zheng,Yuyang Wu,Weilong Xiao
As(III) oxidation to As(V) is deemed necessary for better arsenic removal, and separation is still the optimal approach for water remediation from As(III). Herein, sulfite (SIV) was adopted to activate MnFe 2 O 4 for simultaneous oxidation and adsorption of As(III) in neutral water. The As(III) removal was more efficient than a peroxidation of As(III) followed by adsorption. The adsorption capacity of MnFe 2 O 4 /S(IV) for As(III) (26.257 mg g −1 ) was much higher than those of MnFe 2 O 4 alone for As(III) (9.491 mg g −1 ) and As(V) (9.142 mg g −1 ). The mechanistic study corroborated that intermediate Mn(III) was the dominant oxidant responsible for rapid oxidation of As(III), and the dual roles of S(IV) as a complexing ligand and a precursor of oxysulfur radicals accelerated the redox cycle of Mn(II)/Mn(III). Moreover, S(IV) enhanced arsenic adsorption by driving more production of monodentate complexes. As(III) can be effectively removed over a wide range of temperatures (283.15–313.15 K) and pH (3–10) with the optimal pH of 7. The effect of coexisting ions and reusability of MnFe 2 O 4 were also investigated. Especially, the superior performance of MnFe 2 O 4 /S(IV) for As(III) removal in various water matrixes may help develop new removal technologies based on active Mn(III) for the water decontamination from As(III).
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Materials Chemistry A
·
2020
·Vol. 9
·期 4
·2292-2300
·
IF 11.301
Yafang Qi,Xiaoyue Zhao,Yao Liu,Dongxing Kou,Wenhui Zhou,Zhengji Zhou,Shengjie Yuan,Yuena Meng,Sixin Wu
In Cu2ZnSn(S,Se)4 photovoltaic devices, the exceptionally high density of 2CuZn + SnZn donor defects may induce bandgap fluctuations and thus limit Voc and PCE enhancement. We have previously reported that the partial substitution of Ag for Cu in Cu2ZnSn(S,Se)4 provides a promising way to effectively suppress CuZn defects and considerably enhance the cell performance for Cu2ZnSn(S,Se)4 photovoltaic devices. However, the bandgap fluctuations and detrimental band tailing fundamentally still limit cell performance. On the basis of a Ag-substituted CZTSSe system, in this paper, we demonstrate that partially substituting Zn with Mn could be a feasible tactic to pronouncedly decrease the bandgap fluctuations and prevent detrimental band tailing. Our in-depth investigation reveals that Mn substitution could increase depletion width, decrease the defect densities of the CuZn acceptor and 2CuZn + SnZn donor, and enable grain boundary (GB) inversion in a (Cu,Ag)2ZnSn(S,Se)4-based cell. As a result, an impressive PCE of 11.81% was achieved when the Mn substitution level was 10%, with a Voc of 478 mV, a Jsc of 37.89 mA cm−2, and an FF of 65.23%. This is so far the highest efficiency among Mn-substituted CZTSSe-based photovoltaic devices. By thoroughly understanding these photoelectric properties of the CZTSSe-based photovoltaic devices, we believe that the breakthrough in device efficiency will come soon through our continuous efforts.
✓ 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）