APPLIED CATALYSIS A-GENERAL
·
2019
·
IF 4.63
Liu Zhong,Qingyan Fang,Xin Li,Quan Li,Cheng Zhang,Gang Chen
Various catalysts were synthesized by the redox-precipitation (RP) and co-precipitation (CP) methods, and their catalytic performances for the complete catalytic oxidation of lean methane combustion were investigated. The synthetic catalysts were characterized by BET, XRD, Raman, XPS, TG, UV–vis and H2-TPR. MnCe-RP showed 50% methane conversion to CO 2 at ˜446 °C, which was 23 °C lower the temperature required for MnCe-CP. The active components (K x Mn 8 O 16 ) in the bulk and on the surface of MnCe-RP were confirmed. The redox-precipitation method synthesized open nanorod and nanosphere catalysts containing K x Mn 8 O 16 and Mn 5 O 8 , whereas the co-precipitation method synthesized agglomerate catalysts containing only Mn 5 O 8 . The higher surface-concentrations of Mn 4+ , Ce 3+ and O α on MnCe-RP are beneficial for its higher catalytic performance. Furthermore, the optical bandgap value of MnCe-RP is lower than that of MnCe-CP, and the K ion in K x Mn 8 O 16 may weaken the Mn-O bond, improving the catalyst reducibility, especially for the reduction process of Mn 3 O 4 →MnO.
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
Journal of Cleaner Production
·
2021
·
IF 9.297
Liu Xia,Wenjuan Zhang,Jianyong Che,Jun Chen,Peicheng Wen,Baozhong Ma,Chengyan Wang
Phosphate and fluoride are the two most crucial contaminants in water resources. In this work, fluoride and phosphate were separately removed and recovered from wastewater through the step-by-step precipitation method. The thermodynamic analysis proved that the process could be achieved by controlling the pH value and the optimal operating window was predicted by constructing the lg c -pH diagram of the La–F–P–H 2 O system. Lab-scale experiments were performed using La 3+ as a precipitant and the results were well matched with thermodynamic analysis. It indicated that the precipitation of LaF 3(s) was predominated at 1.0< pH < 4.0 with slight precipitation of phosphate, while LaPO 4(s) was primarily formed at a pH range of 5.0–11.0 with fluoride left in the solution. Furtherly, the generated LaF 3 and LaPO 4 were treated with NaOH solution to regenerate the precipitant and recycle fluorine and phosphorus, and the regeneration efficiency reached 97.4% and 74.3%, respectively. Eventually, the continuous experiment for the simulated wastewater revealed that 97.7% of fluoride and 99.9% of phosphate could be removed and recovered by the proposed stepwise precipitation method. The process is eco-friendly and sustainable, not only realizing the removal and recovery of F and P efficiently but also making them separated.
研究领域:
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
DESALINATION
·
2025
·
IF 9.8
Shishuo Wang,Fei Guo,Xuemei Wu,Yuandong Jia,Gaohong He,Xiaobin Jiang
Lithium and its compounds are critical strategic resources with wide-ranging applications. This study developed a bipolar membrane precipitation coupled electrodialysis enrichment (BMp-EDe) process for extracting lithium from brines with an Mg/Li ratio of 20. The method is based on phase separation achieved through precipitation-coupled ion permeation and a synergistic mechanism for ion enrichment, resulting in significant process intensification. Key factors such as current density, molar ratio between diluate and base chambers, and base chamber concentration were optimized to control nucleation and prevent membrane fouling. Under conditions of current density ranging from 200 to 400 A·m −2 and a molar ratio of the diluate chamber to the base chamber between 13 and 16, the magnesium removal rate in the BMp-EDe process is found to exceed 99.90 %, with a separation factor greater than 20,000. The optimal separation factor is observed to reach 40,244, with a magnesium removal rate as 99.96 % and a lithium recovery rate as 95.32 %. With optimized operation conditions, the energy consumption of magnesium precipitation decreased from 11.89 kWh·kg −1 (Mg 2+ ) to 7.97 kWh·kg −1 (Mg 2+ ). Thus, an alternative method is presented that employs commercial bipolar membranes to achieve ultra-high magnesium‑lithium separation efficiency. Additionally, a mechanism for the continuous operation of the magnesium precipitation chamber is validated, which can effectively prevent membrane fouling.
研究领域:
化学工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF RARE EARTHS
·
2016
·
IF 2.188
Siyuan CHEN,Jintai FAN,Liangjie PAN,Benxue JIANG,Xiaojian MAO,Rihong LI,Xinqiang YUAN,Xiongwei JIANG,Long ZHANG
Yb:Lu 3 Al 5 O 12 (Yb:LuAG) nano powders were synthesized with the co-precipitation method from cation (Lu 3+ , Yb 3+ , Al 3+ ) solution of different concentrations using NH 4 HCO 3 as the precipitant. The influence of cation concentration on the morphology and purity of the calcined powders was studied. Contrary to the conventional suggestion that recommends thin solution to obtain loosely agglomerated nano powders, results showed that thin cation (Lu+Yb+Al) concentration ≤0.08 mol/L led to formation of Al 2 O 3 and LuAP impurities in the obtained nano powders. By means of Tg/(DTA), X-ray diffraction (XRD), scanning electron microscopy (SEM), the cause was revealed to be re-dissolution of Lu at high pH value that resulted from the decomposition of NH 4 HCO 3 . (Lu+Yb+Al) concentration of ∼0.24 mol/L was recommended to achieve pure Yb:LuAG nano powders. Transparent Yb:LuAG ceramics were fabricated with the prepared Yb:LuAG nano powders. The transmittance around 800 nm was 77.5%.
研究领域:
材料科学
·
光学材料
✓ 已验证
产品关联
DOI
高影响因子
Materials
·
2015
·Vol. 8
·期 8
·5363-5375
·
IF 2.651
Liangjie Pan,Benxue Jiang,Jintai Fan,Qiuhong Yang,Chunlin Zhou,Pande Zhang,Xiaojian Mao,Long Zhang
The synthesis of pure and well dispersed lutetium aluminum garnet (LuAG) powder is crucial and important for the preparation of LuAG transparent ceramics. In this paper, high purity and well dispersed LuAG powders have been synthesized via co-precipitation method with lutetium nitrate and aluminum nitrate as raw materials. Ammonium hydrogen carbonate (AHC) was used as the precipitant. The influence of aging time, pH value, and dripping speed on the prepared LuAG powders were investigated. It showed that long aging duration (>15 h) with high terminal pH value (>7.80) resulted in segregation of rhombus Lu precipitate and Al precipitate. By decreasing the initial pH value or accelerating the dripping speed, rhombus Lu precipitate was eliminated and pure LuAG nano powders were synthesized. High quality LuAG transparent ceramics with transmission >75% at 1064 nm were fabricated using these well dispersed nano LuAG powders.Keywords:co-precipitation method;single phase;pH values;LuAG powder;transparent ceramics
研究领域:
材料科学
·
无机化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Foods
·
2023
·Vol. 12
·期 7
·1415
·
IF 5.2
Shenglan Lu,Xueying Li,Xunran Wei,Caihuan Huang,Jie Zheng,Shiyi Ou,Tao Yang,Fu Liu
In contrast to their well-known physiological properties, phytochemicals, such as flavonoids, have been less frequently examined for their physiochemical properties (e.g., surface activity). A natural quercetin self-stabilizing Pickering emulsion was fabricated and characterized in the present study. The antisolvent precipitation method was used to modify quercetin (in dihydrate form), and the obtained particles were characterized by light microscope, atom force microscope, XRD, and contact angle. The antisolvent treatment was found to reduce the particle size, crystallinity, and surface hydrophobicity of quercetin. We then examined the effects of the antisolvent ratio, particle concentration, and oil fraction on the properties of the quercetin particle-stabilized emulsions. In addition, increasing the antisolvent ratio (1:1~1:10) effectively improved the emulsification performance of the quercetin particles. The emulsion showed good storage stability, and the particle size of the emulsion decreased with the rising particle concentration and increased with the rising oil phase ratio. The findings indicate that natural quercetin treated with antisolvent method has a good ability to stabilize Pickering emulsion, and this emulsion may have good prospective application potential for the development of novel and functional emulsion foods.Keywords:quercetin;Pickering;antisolvent precipitation;crystalline
研究领域:
食品科学
·
胶体化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
BULLETIN OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY
·
2021
·Vol. 107
·期 1
·167-174
·
IF 2.151
Zhong Kai,Zhang Chaolan,Ren Siwei,Huang He,Rong Qun,Zhou Yongxin
Layered double hydroxides (LDHs) are promising soil contamination amendment agents for its efficient absorbing abilities. However, the application of LDHs in remediation of heavy metal contaminated soil are to be developed. In this study, we synthesized MgAlFe-LDHs by introducing Fe 3+ into interlayer of the MgAl-LDHs using co-precipitation method. X-ray diffraction (XRD), Fourier transform infrared spectrometer (FT-IR) and scanning electron microscope (SEM) were employed to characterized the micro structure of MgAlFe-LDHs. And then pot incubation and pilot experiments were conducted to investigate the heavy metal removal efficiencies of MgAlFe-LDHs and its potential being applicated in As contaminated soil amendment from a deserted arsenic plant site. Incubation experiments showed that the MgAlFe-LDHs had a higher removal efficiency on arsenic contaminated soil compared to other agents. And the results of pilot experiments indicated that the MgAlFe-LDHs can immobilize up to 90% of the As in soil with 5% (w/w) addition. Based on the results above, MgAlFe-LDHs are promising materials amending the heavy metal contaminated soil with practical application value.
研究领域:
环境科学
·
土壤学
✓ 已验证
DOI
PubMed
高影响因子
Catalysts
·
2019
·Vol. 9
·期 6
·519
·
IF 3.444
Jiaming Shao,Fawei Lin,Yan Li,Hairong Tang,Zhihua Wang,Peixi Liu,Guanyi Chen
NO oxidation was conducted over MnOx-CeO2catalysts, which were synthesized by the co-precipitation method. The calcination temperature and third metal doping were the main considerations. MnCe catalysts calcined at 350 °C and 450 °C attained the highest NO conversion efficiency, compared to 550 °C. XRD results suggested that the higher the calcination temperature, the higher the crystallization degree, which led to a negative effect on catalytic activity. Subsequently, Sn, Fe, Co, Cr, and Cu were separately doped into MnCe composites, but no improvement was observed for these trimetallic catalysts in NO conversion. Nevertheless, MnCeSn, MnCeFe, and MnCeCo still exhibited a desirable NO conversion efficiency, so they were tested under SO2addition together with MnCe catalyst. Among them, MnCeFe exhibited the highest NO conversion after whole poisoning testing. XPS results indicated that Fe could protect Mn and Ce metal oxides from being reduced during SO2poisoning process. Furthermore, in in-situ DRIFTS measurement, part of nitrate species maintained undestroyed on the MnCeFe catalyst surface after SO2poisoning. These characteristics reinforced that Fe dropping would achieve better performance under SO2atmosphere.Keywords:MnOx-CeO2;co-precipitation;NO oxidation;SO2resistance;metal addition
研究领域:
环境科学
·
催化化学
✓ 已验证
DOI
高影响因子
JOURNAL OF ENVIRONMENTAL MANAGEMENT
·
2017
·
IF 4.01
Xueyi Guo,Xiao Cao,Guoyong Huang,Qinghua Tian,Hongyu Sun
A novel process of lithium recovery as lithium ion sieve from the effluent obtained in the process of spent lithium-ion batteries recycling is developed. Through a two-stage precipitation process using Na 2 CO 3 and Na 3 PO 4 as precipitants , lithium is recovered as raw Li 2 CO 3 and pure Li 3 PO 4 , respectively. Under the best reaction condition (both the amounts of Na 2 CO 3 and Li 3 PO 4 vs . the theoretical ones are about 1.1), the corresponding recovery rates of lithium (calculated based on the concentration of the previous stage) are 74.72% and 92.21%, respectively. The raw Li 2 CO 3 containing the impurity of Na 2 CO 3 is used to prepare LiMn 2 O 4 as lithium ion sieve, and the tolerant level of sodium on its property is studied through batch tests of adsorption capacity and corrosion resistance . When the weight percentage of Na 2 CO 3 in raw Li 2 CO 3 is controlled less than 10%, the Mn corrosion percentage of LiMn 2 O 4 decreases to 21.07%, and the adsorption capacity can still keep at 40.08 mg g −1 . The results reveal that the conventional separation sodium from lithium may be avoided through the application of the raw Li 2 CO 3 in the field of lithium ion sieve.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2012
·
IF 1.289
Chun-Hui Du,Chun-Jin Wu,Li-Guang Wu
Amphiphilic copolymer Pluronic F127 was used as macromolecular additive to investigate the polymorphism and thermoresponsive properties of poly(vinylidene fluoride) (PVDF) membranes. Fourier transform infrared spectrometer (FTIR), X-ray diffraction (XRD), and scanning electron microscopy (SEM) were conducted to characterize the polymorphism and morphology of PVDF/F127 blend membranes. FTIR results indicated that F127 existed stably in the blend membranes, and lower F127 concentration in the cast solution was in favor of the formation of α-crystal phase, but higher F127 concentration could promote the formation of β- and γ-crystal phase in PVDF membranes. The results of XRD also confirmed these phenomena. With the increase of F127 in the cast solutions, a more sponge-like structure appeared at the bottom surface of the membranes as investigated by SEM. PVDF/F127 blend membranes also exhibited good thermoresponsive properties. The water flux of the membranes increased distinctly with the increase of the experimental temperature, decreased with the decrease of the temperature, and the increasing and decreasing curves were almost overlapped. Contact angle measurement and permeation experiment indicated that the blend membranes had good hydrophilicity and fouling resistance. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
研究领域:
材料科学
·
高分子化学
·
膜技术
✓ 已验证
产品关联
DOI
高影响因子
OPTICAL MATERIALS
·
2019
·
IF 2.687
Penghui Chen,Qiang Liu,Yagang Feng,Xiaoying Li,Xiaopu Chen,Yumin Liu,Jiang Li
Y 0.16 Zr 0.84 O 1.92 transparent ceramics were successfully fabricated by air pre-sintering combined with HIP post-treatment from the nanopowder synthesized by the co-precipitation method. Fine and low-agglomerated Y 0.16 Zr 0.84 O 1.92 powder with the average particle size of 14.8 nm was obtained by calcining the precursor at 800 °C for 4 h. The influences of pre-sintering temperature on the microstructure and optical quality of Y 0.16 Zr 0.84 O 1.92 ceramics were investigated. It is found that the relative density of pre-sintered Y 0.16 Zr 0.84 O 1.92 ceramics increases from 82.1% to 96.1% and the average grain size increases from 0.6 μm to 6.0 μm with the pre-sintering temperature increasing from 1250 °C to 1500 °C. The Y 0.16 Zr 0.84 O 1.92 ceramic sample pre-sintered at 1300 °C for 2 h and HIP post-treated at 1800 °C for 3 h without sintering additives exhibits the best transparency. In-line transmittance of Y 0.16 Zr 0.84 O 1.92 ceramics with the thickness of 1.0 mm reaches 72.4% at 800 nm, which is near to the theoretical transmittance.
研究领域:
材料科学
·
光学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY
·
2017
·Vol. 17
·期 4
·2613-2619
·
IF 1.483
Feng Zhao,Qi Jianqi,Huang Zhangyi,Xie Xiumin,Wei Nian,Lu Tiecheng
Single-phase nano-crystalline yttria-stabilized zirconia (YSZ) powder was prepared by co-precipitation method using zirconium oxychloride (ZrOCl2 · 8H2O) and yttrium nitrate (Y(NO3)3 · 6H2O) as raw materials and ammonium
bicarbonate (NH4HCO3) and liquor ammonia (NH4OH) as the precipitators. In order to get the powder with favorable dispersibility, polyethylene glycol (PEG, HO(CH2CH2O)
n
H) with different molecular weights and amounts was
used as a dispersant agent in the synthesis process and its effects on the YSZ powder was investigated. The scanning electron micrograph (SEM) images showed that the degree of agglomeration and the mean crystal size of YSZ powder varied with the amount and the molecular weight of PEG. The
appropriate amount and molecular weight of PEG were given by comparing the dispersibility and crystal size distribution of powders. In the process, one also could find that the promotion of dispersion was insensitive to the molecular weight, and all PEG (400–2000) can exert an ability
to reduce the agglomeration. The proper amount of PEG400, PEG600, PEG1000, PEG2000 was 3 wt%, 3 wt%, 2 wt%, 2 wt%, respectively. The transmission electric microscope studies in conjunction with the XRD analyzes verified the low degree of agglomeration and the size of YSZ powder varied between
10~20 nm.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）