DALTON TRANSACTIONS
·
2018
·Vol. 47
·期 11
·3864-3871
·
IF 4.099
Aolei Gao,Zhenhua Sun,Shaopeng Li,Xinjuan Hou,Huiquan Li,Qisheng Wu,Xinguo Xi
Li1.6Mn1.6O4 is a representative ion sieve material that is used to recover lithium from salt brines and bitterns owing to its high lithium ion adsorption capacity reaching 11.9–44 mg g−1. However, manganese dissolution during acid treatment hinders the industrial application of the material. For investigating the mechanism of manganese dissolution, the precursor Li1.6Mn1.6O4 and ion sieve H1.6Mn1.6O4 were prepared and characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FT-IR), chemical content analyses, diffuse reflectance infrared Fourier-transform spectroscopy (DRIFTS), and X-ray photoelectron spectroscopy (XPS). The results of XRD, SEM, and FT-IR showed that the bulk phase of Li1.6Mn1.6O4 retained the spinel structure, whereas the lattice diminished during acid treatment. The results of chemical content analyses showed that the bulk phase of Li1.6Mn1.6O4 contained a few trivalent manganese atoms and that the mean valence of manganese in the material increased during acid treatment. DRIFTS and XPS exhibited that the surface of Li1.6Mn1.6O4 was mostly full of tetravalent manganese and retained the spinel structure during acid treatment. In the proposed mechanism of manganese dissolution, an electron of trivalent manganese in the bulk phase transfers to the surface and is captured by tetravalent manganese within the acidic environment. Then, tetravalent manganese is converted to bivalent manganese after acquiring sufficient electrons, and dissolution occurs simultaneously.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
PubMed
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2021
·
IF 19.503
Runren Jiang,Guanghua Lu,Min Wang,Tianjian Dang,Jianchao Liu,Zhenhua Yan
Utilizing photocatalysis to degrade pollution is emerging as a promising way to treat wastewater, but is challenged by low efficiency and scanty toxicity cognition. In this work, Mn 3 O 4 /BiOCl based crystal plane engineering systems are applied for naproxen (NPX) degradation, and Mn 3 O 4 /BiOCl 010 displayed better degradation rate, which is 16 and 8 times than that of the Mn 3 O 4 /BiOCl 001 and BiOCl 010 . According to the degradation pathway analysis and biological toxicity experiments, the toxicity of the degradation solution increased first and then decreased, which may be caused by the mineralization of NPX and more toxic intermediates. Affected by the distinct internal charge transfer directions of the two crystal planes of BiOCl, Mn 3 O 4 /BiOCl 010 heterojunction system has a faster charge transform than that of Mn 3 O 4 /BiOCl 001 . Moreover, the valence cycle of Mn can further accelerate the charge transfer, which can also provide a powerful driving force for NPX elimination.
研究领域:
环境科学
·
光催化
·
毒理学
✓ 已验证
产品关联
DOI
高影响因子
Chinese Physics B
·
2022
·Vol. 31
·期 6
·068201
·
IF 1.652
Yuejun Ding,Feixiang Ding,Xiaohui Rong,Yaxiang Lu,Yong-Sheng Hu
Na-ion batteries (NIBs) are regarding as the optimum complement for Li-ion batteries along with the rapid development of stationary energy storage systems. In order to meet the commercial demands of cathodes for NIBs, O3-type Cu containing layered oxide Na0.90Cu0.22Fe0.30Mn0.48O2 with good comprehensive performance and low-cost element components is very promising for the practical use. However, only part of the Cu3+/Cu2+ redox couple participated in the redox reaction, thus impairing the specific capacity of the cathode materials. Herein, Mg2+-doped O3-Na0.90Mg0.08Cu0.22Fe0.30Mn0.40O2 layered oxide without Mn3+ was synthesized successfully, which exhibited improved reversible specific capacity of 118 mAh/g in the voltage range of 2.4–4.0 V at 0.2 C, corresponding to the intercalation/deintercalation of 0.47 Na+ (0.1 more than that of Na0.90Cu0.22Fe0.30Mn0.48O2). This work demonstrates an important strategy to obtain advanced layered oxide cathodes for NIBs.
研究领域:
电化学储能
·
材料科学
·
无机化学
·
能源材料
·
固态化学
✓ 已验证
DOI
高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2017
·Vol. 24
·期 8
·7499-7510
·
IF 2.741
Yu Chenglong,Chen Feng,Dong Lifu,Liu Xiaoqing,Huang Bichun,Wang Xinnan,Zhong Shengbang
Manganese-rich MnSAPO-34 molecular sieves were prepared by one-pot synthesis method for NO
x
abatement using the ammonia-selective catalytic reduction (NH 3 -SCR) technology and characterized using ICP, BET, XRD, FE-SEM, H 2 -TPR, NH 3 -TPD, XPS, and DR UV-Vis analyses. The experimental results indicate that the Mn content and chemical state, as well as the surface acidity, of the MnSAPO-34 molecular sieves significantly enhance their DeNO
x
efficiency at low temperatures (ca. 200–300 °C). The manganese-rich MnSAPO-34 was synthesized using a combination of triethylamine and diisopropylamine as the structural directing agents and high Mn loading ( n (MnO)/ n (P 2 O 5 ) = 0.4). The resulting catalyst exhibits the highest activity among all of the samples with a NO
x
conversion value of nearly 95% and a N 2 selectivity that is higher than 90% at 220–400 °C. In addition, this catalyst presents higher NO
x
conversion than the conventional V 2 O 5 -WO 3 /TiO 2 catalysts and other SAPO-based catalysts below 300 °C. Furthermore, the analytical results indicate that the manganese species in the catalyst are mainly in the form of a framework Mn(IV), which could play a significant role in the NH 3 -SCR process as the specific active species. The results suggest that controlling the types and content of the organic amine templates and variations in the surface acidity of the catalysts may significantly enhance the SCR activity at lower temperatures.
研究领域:
环境催化
·
材料化学
·
工业催化
·
大气污染控制
·
无机多孔材料
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）