ACS Omega
·
2021
·
IF 3.512
Xiutao Li,Feng Zhang,Mengjie Zhang,Xiaomeng Zhou,Haijun Zhang
In this work, a series of rare earth-based metal–organic frameworks (RE-MOFs) with the same organic ligand were synthesized and studied as flame retardants on epoxy. Through thermogravimetric analysis, limiting oxide index, UL-94, and cone calorimeter tests, a Y-based MOF (Y-MOF) showed the best flame retardancy compared with a La-based MOF (La-MOF) and Ce-based MOF (Ce-MOF). Further research with Raman, X-ray photoelectron spectroscopy, and theoretical calculation revealed that the reasons for the different flame retardance performances of RE-MOFs resulted from the catalytic carbonizing abilities and the radical-trapping abilities of La, Ce, and Y.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
·
2021
·
IF 5.302
Yongchang Guo,Ying Zhang,Mathieu Allix,Shaowei Feng,Hong Sun,Cécile Genevois,Emmanuel Véron,Jianqiang Li
Pyrochlore-based glass-ceramics are attracting attention as a promising host material for immobilizing minor actinide in high-level wastes. However, the loading capacity of pyrochlore-based materials for actinide elements is to be improved, and only conventional synthetic approaches of powder sintering and glassy bulk crystallization were reported. Here, new (La,Y) 2 (Zr,Ti) 2 O 7 pyrochlore-based glass-ceramics were subtly designed and successfully prepared through a rapid melting and solidification process. The solidification behavior of samples with different cooling rates was investigated, the dense and crack-free (La,Y) 2 (Zr,Ti) 2 O 7 pyrochlore-based glass-ceramics were prepared at the cooling rate of 500 °C/s (within 1.5 s). The present amorphous La 2 O 3 -TiO 2 -Al 2 O 3 phase demonstrates the outstanding thermal stability compared with the currently used borosilicate glass for high-level waste immobilization due to the lack of conventional glass-forming components. The results show the great feasibility of this novel synthesis route for glass-ceramics by direct solidification and its good potential for immobilizing high-level wastes.
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2021
·
IF 10.588
Zhuo-Rui Jiang,Yuxin Li,Deyun Zhang,Yu-Xiao Zhou,Genbao Xu,Changhua Wang,Yeqing Lan,Jing Guo
Arsenite (As(III)) is more toxic and difficult to remove than arsenate (As(V)). In this study, an S-doped Cu-La bimetallic oxide (S-CuLaO) decorated with metal-organic framework (MOF) composite (S-CuLaO@UIO-66) was synthesized and applied for the adsorption of As(III). The maximum adsorption capacity of As(III) by S-CuLaO@UIO-66 was as high as 171 mg/g, which was much higher compared with other MOF compounds reported to date. The UIO-66 support improved the dispersion and reduced the size of the S-CuLaO particles, which increased the number of exposed adsorption reactive sites. Study of the mechanism revealed that the synchronous oxidation and adsorption significantly increased the removal of As(III). O 2 ∙ - was produced by the receiving electron from the dissolved oxygen from Cu(I) in S-CuLaO, which converted As(III) to As(V). Furthermore, the stability and reusability S-CuLaO@UIO-66 (without regeneration) was investigated at a low As(III) concentration (approximately 1000 µg/L) in deionized water and well water. The residual arsenic concentration ranged from 0.8 to 2.8 μg/L in deionized water and 3–58.2 μg/L in well water within 240 min during three cycles. Generally, this study suggests that combining an optimal oxide with a stable MOF is a promising approach for the fabrication of composite adsorbents.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF SOLID STATE CHEMISTRY
·
2019
·
IF 2.291
Peixi Hao,Linwen Jiang,Hanlei Zhao,Jiangtao Li,Shiwen Qiu,Hongbing Chen
The MFeO 3 : R 3+ (M = La, Gd; R = Eu, Er, Ho) nanocrystalline powders were successfully synthesized by the sol–gel combustion method using glycine-based gel at a low ignition temperature. The as-burnt products present honeycomb-like structure with many irregular continuous pores due to the releasing of a large amount of gas during the combustion reaction process. The lattice parameters and cell volumes of MFeO 3 :R 3+ (M = La, Gd; R = Eu, Er, Ho) nanocrystalline powders are compared in detail. The magnetic properties of all the samples were studied systematically. The results show that the doping of rare-earth ions enhanced greatly the coercivity of GdFeO 3 and LaFeO 3 as a result of the enhancement of magnetic anisotropy . The influence of doped rare-earth ions on the magnetic properties was summarized. The distinction of magnetism of MFeO 3 :R 3+ (M = La, Gd; R = Eu, Er, Ho) were explained in detail by the intrinsic magnetism of doped rare-earth ions. This work is significant for the application of rare-earth elements in other magnetic materials.
✓ 已验证
产品关联
DOI
高影响因子
CLAYS AND CLAY MINERALS
·
2019
·Vol. 67
·期 4
·253-264
·
IF 1.835
Xu Minhong,Qian Mengxia,Pan Guoxiang,Guo Yuhua,Wu Tao
Photocatalytic degradation of polluted water by means of minerals, such as clays and oxides, which have surfaces that exhibit catalytic properties, has been suggested to be a useful new strategy to promote both organic and inorganic pollutant degradation. Nevertheless, much still remains to be studied about the capability of mixed metal oxides derived from lanthanum-containing layered double hydroxides to promote pollutant removal by means of photocatalytic degradation with the mineral surfaces. The objective of the present study was to investigate the synthesis of ternary MgAlLa mixed-metal oxides (MgAlLa-M) with various Mg/Al/La molar ratios through a hydrotalcite-like precursor route by co-precipitation of appropriate amounts of metal salts from homogeneous solution, followed by calcination at 600°C. The crystal structure, surface morphology, and optical properties of the samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), and UV-Vis diffuse reflectance spectroscopy (DRS). Analysis by XRD showed that MgO, La 2 O 3 , MgAl 2 O 4 , and La 10 Al 4 O 21 phases coexisted in calcined samples as MgAlLa-M. The samples showed a small band gap of 3.11–3.35 eV according to DRS. The photocatalytic activities of the samples were evaluated by degradation of methylene blue (MB) under visible light irradiation. MgAlLa-M had better photocatalytic properties than hydrotalcite precursors, and the MgAlLa-0.5-M possessed the best photocatalytic activity. The photocatalytic degradation efficiency of MB dye with MgAlLa-0.5-M under visible light irradiation for 1 h was 99.89% in the presence of H 2 O 2 , which exceeded the binary MgAl-M (84.06%) under the same conditions. The high photocatalytic activity of the sample was attributed to the addition of La(III). In addition, the possible mechanism of photocatalytic degradation of MB by MgAlLa-M was discussed. The results showed that •O 2 – plays a major role in the MgAlLa-0.5-M/H 2 O 2 system.
✓ 已验证
产品关联
DOI
高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2023
·Vol. 30
·期 49
·108230-108246
·
IF 5.8
Zhang Xiao,Luo Shiwen,Duan Jiaxin,Lan Tao,Wei Yun
Adsorption is an effective method for the removal of hazardous substances from wastewater. In this work, a low-cost and environmental-friendly composite hydrogel material of sodium alginate doped with nitrogen doped carbon dots (SA@NCDs) was fabricated by impregnation for lanthanide and enhanced phosphorus adsorption in wastewater. The effects of NCDs doping amount, dosage, pH, initial solution concentration, adsorption time and temperature on the process of La (III) adsorption by SA@NCDs were investigated. The adsorption isotherms fitted to Langmuir isotherm model (R 2 = 0.9970–0.9989) and the adsorption kinetics followed pseudo-second-order kinetic model (R 2 = 0.9992). The maximum adsorption capacity of the adsorbent for La (III) was 217.39 mg/g according to the Langmuir model at 298.15 K. After five cycles, the removal efficiency of La (III) adsorbed by SA@NCDs was still 85.1%. Moreover, the loaded La (III) enhanced the adsorption of phosphorus. The La (III)-SA@NCDs-5 hydrogel adsorbent greatly improved the adsorption capacity for phosphorus compared with the La (III)-free adsorbent, and the adsorption amount can reach 9.64 mg-P/g. The SA@NCDs complex hydrogels for rare earth adsorption were prepared by introducing NCDs rich in amino group into SA hydrogels. The introduction of NCDs increases the adsorption sites of hydrogels, and also overcomes the problem that NCDs itself is difficult to recover in wastewater treatment applications. The lanthanide adsorbed material has a stable structure and can be used to remove phosphorus to deal with waste using the waste. It indicates the SA@NCDs hydrogel composite adsorbent have good potential for wastewater treatment. Graphical Abstract
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMOSPHERE
·
2023
·
IF 8.8
Hoang Nguyen Tien,Fredrick M. Mwazighe
In this work, a novel La-doped βPbO 2 (Ti/SnO 2 –Sb/La-βPbO 2 ) was prepared using electrodeposition method and applied to the degradation of prednisolone (PRD), 8-Hydroxyquinoline (8-HQ), and other typical organic pollutants. Compared with the conventional electrode Ti/SnO 2 –Sb/βPbO 2 , La 2 O 3 doping enhanced oxygen evolution potential (OEP), reactive surface area, stability and repeatability of the electrode. The 10 g L −1 of La 2 O 3 doping exhibited the highest electrochemical oxidation capability of the electrode with [•OH]ss being determined at 5.6 × 10 −13 M. The quenching experiments were conducted to confirm the main oxidizing species (here: •OH) in the electrochemical process. The study showed that the pollutants were removed in the electrochemical (EC) process with different degradation rates and indicated that the second-order rate constant of organic pollutants towards •OH ( k OP,•OH ) has a linear relationship with the degradation rate of organic pollutants ( k OP ) in the electrochemical process. Another new finding in this work is that a regression line of k OP,•OH and k OP can be used to estimate k OP,•OH of an organic chemical, which cannot be determined using the competition method. k PRD,•OH and k 8-HQ,•OH were determined to be 7.4 × 10 9 M −1 s −1 and (4.6–5.5) × 10 9 M −1 s −1 , respectively. Compared with conventional supporting electrolyte (like SO 4 2− ), H 2 PO 4 − and HPO 4 2− improved k PRD and k 8-HQ by 1.3–1.6-fold, while SO 3 2− and HCO 3 − inhibited k PRD and k 8-HQ significantly, down to 80%. Additionally, the degradation pathway of 8-HQ was proposed based on the detection of intermediates from GC-MS.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Materials Chemistry A
·
2019
·Vol. 7
·期 16
·9903-9911
·
IF 10.733
Kun Wang,Qilu Yao,Shaojun Qing,Zhang-Hui Lu
Hydrous hydrazine (N2H4·H2O) is considered to be a promising chemical hydrogen storage carrier due to its high hydrogen content (8.0 wt%), production of only N2 in addition to H2, and facile recharging as a stable liquid. In this work, for the first time, CoPt NPs supported on La(OH)3 are used as a highly effective catalyst for selective decomposition of N2H4. Surprisingly, the La(OH)3 nanosheet-supported CoPt NPs exhibit superior catalytic performance, releasing 3 equiv. (H2 + N2) with turnover frequency (TOF) values of up to 734.2 h−1 at 303 K and 2400 h−1 at 323 K; these are higher than those of most reported catalysts for the dehydrogenation of N2H4. Especially, CoPt/La(OH)3 can be easily separated from the reaction solution using a magnet due to its super-paramagnetic nature, and it can maintain its high activity and 100% selectivity even after five cycles. The high performance of CoPt/La(OH)3 can be attributed to the electronic interaction between Co and Pt, strong basic sites on the surface of La(OH)3 and a synergistic cooperative effect between the ultrafine CoPt NPs and the La(OH)3 support. The development of a high performance Co-based catalyst may promote the effective application of hydrous hydrazine as a promising hydrogen storage material.
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS
·
2019
·
IF 3.47
Zhi Zheng,Jun Wang,Yi Wei,Xuejun Liu,Fengwen Yu,Jianbing Ji
La-Fe modified Si-MCM-41 (La-Fe/Si-MCM-41) catalysts were prepared by the wet impregnation method and used in catalytic cracking of soybean oil (CCS) for biofuel production. The catalysts were characterized by BET, XRD, XPS, Py-FTIR and CO 2 -TPD. The results showed that the aromatics content increased with the increase in B/L value, while the content of oxygenated compounds decreased, indicating that Brönsted acid sites were the major active sites for deoxygenation and aromatization reactions. Compared with Si-MCM-41, the Brönsted acidity of LFM-6 sharply decreased from 22.49 to 5.86 μmol g −1 . Accordingly, the aromatics content was reduced from 37.51 wt.% to 14.52 wt.% which was lower than the limitation (15 wt.%) according to the global environmental legislation. However, for the LFM-6 catalyst, the excessive loss of Brönsted acid sites and sharp decrease in BET surface area and pore volume led to the decrease in deoxygenation. As a result, the fatty acids content increased from 2.71 wt.% to 16.67 wt.% and the acid value reached 35.20 mgKOH g −1 . When the La-Fe loading increased to 15 wt.%, part of fatty acids were converted into ketones by the active sites on Fe 2 O 3 /La 2 O 3 and strong Lewis acid sites on catalysts. Besides, the new weak Lewis acid and basic sites on Fe 2 O 3 /La 2 O 3 exhibited the synergistic effect on promoting the generation of alkenes. The CaO/LFM-6 composite catalysts prepared by the mechanical mixing of LFM-6 and CaO were used in CCS to reduce the acid value of biofuel. LFM-6-C-3 was proved to be an effective catalyst for CCS to produce biofuel with low aromatics (12.31 wt.%) and fatty acids (2.76 wt.%) content.
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2015
·Vol. 5
·期 55
·43906-43916
·
IF 3.84
Zakir Hussain,Li Daosheng,Li Xi,Kang Jianxiong
A study has been designed for a fluoride adsorbent synthesized by a co-precipitation approach of Mg(II), Al(III) and La(III) salts (MAL) in 2 : 1 : 2 ratios. The prepared material illustrated relatively stable fluoride adsorption potential and an amorphous structure at temperatures lower than 600 °C. The defluoridation capacity of a 2 g L−1 adsorbent dose at room temperature was observed to be between 24.08 to 98.28% for a 10 and 20.66 mg L−1 fluoride solution in a broad pH range (2 to 12), while for a 45.45 mg L−1 solution, it varied between 26.49 to 80.42%. The adsorption process on MAL was endothermic in nature (−ΔG), follows pseudo second order kinetics (R2 = 0.999) and best fitted with a Langmuir sorption isotherm model (R2 = 0.9985). The prepared material was characterized by XRD, SEM, BET, EDX, FTIR and XPS, whereas contact times, sorption kinetics, dosage and the effect of major co-existing anions were carried out for the optimization of the adsorbent. In addition to amphoteric behavior of Al(III) in the composite material, the effect of fluoride concentration and sorbent quantity in a batch process appeared to be important factors in maintaining the near neutral pH of the treated water. Similarly, one other factor, flow rate was found to affect the pH in the column adsorption process. Regeneration of up to 95.71% of the fluoride loaded adsorbent was achieved with a methanol and HCl mixture. The results showed that Al(III) acted as amphoteric reagent and keeps the pH within drinking water range or near neutral.
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2014
·Vol. 4
·期 13
·6500-6507
·
IF 3.708
Zhujian Huang,Pingxiao Wu,Hailing Li,Wen Li,Yajie Zhu,Nengwu Zhu
A series of La and Ce doped hydroxyl FeAl intercalated montmorillonite (FeAl-Mt) were prepared by a co-intercalation method for catalytic oxidation of Reactive Blue 19 (RB19) by a heterogeneous photo Fenton process under natural sunlight irradiation. The physicochemical properties of the obtained catalysts were deciphered by X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, X-ray photoelectron spectroscopy (XPS), X-ray absorption fine structure (XAFS) and UV-vis diffuse reflectance spectroscopy (DRS). The results showed that Ce or La doped FeAl Keggin polyoxocations were intercalated into the gallery of montmorillonite and the physicochemical properties of intercalated FeAl Keggin polyoxocations were mildly changed after Ce or La doping, resulting in defects and lattice vacancies. The doping of Ce or La could effectively improve the catalytic performance of FeAl-Mt measured by heterogeneous photo Fenton degradation of RB19 catalyzed by the obtained products. The synergistic effect between the doped element and FeAl intercalated montmorillonite played a crucial role in the enhancement of heterogeneous catalytic activity under natural sunlight irradiation.
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF NON-CRYSTALLINE SOLIDS
·
2024
·
IF 3.2
Jie Feng,Yongchang Zhu,Jichuan Huo,Zhu Cui,Liu Yang,Jing Li,Qian Wu
In this paper, using borosilicate glass was used as the base glass, using La 2 O 3 ,CeO 2 simulated trivalent and tetravalent lineage actinide nuclides, study the interaction between La 2 O 3 and CeO 2 in borosilicate and the properties of the cured body, and obtain the borosilicate cured body sample by solid melting method. By XRD, SEM-EDS, FTIR test results showed that adding CeO 2 at the fixed La 2 O 3 content will reduce the packing capacity of borosilicate glass to La 2 O 3 , but adding La 2 O 3 at the fixed CeO 2 content will increase the packing capacity of borosilicate glass to CeO 2 . Density tests showed that adding CeO 2 at the fixed La 2 O 3 content will increase the cured body density and then decrease, but adding La 2 O 3 at the fixed CeO 2 content will only increase the cured body density all the time.The results of 28 days of leaching experiments showed that the leaching rate of Ca and Si elements was kept at 10 –4 dot product in all samples, while the leaching rate of La and Ce elements remained at 10 –6 dot product or even lower, indicating the good chemical stability of the cured body.
✓ 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）