Journal of Building Engineering
·
2024
·
IF 6.7
Wenjie Liu,Biqin Dong,Peiyu Chen,Lei Zeng,Ming Peng,Xiang Wang,Yanshuai Wang,Shuxian Hong
In situ growth of different anion-intercalated layered double hydroxide (LDH) films on steel substrates for corrosion resistance has been achieved via the electrodeposition-hydrothermal method, but its growth process remains unclear. In this study, the effects of electrodeposition potential (−1.1 to −1.4 V) on the formation and growth mechanism of Zn/Al-NO 3 − -LDH films were investigated using XRD, FTIR, and SEM techniques. The results demonstrated that weak potentials either failed to form the LDH film or caused cracks, while excessive potentials resulted in hydrogen evolution and the formation of heterogeneous ZnO. The LDH films prepared at the optimal potential of −1.3 V were dense and uniform, with an adhesion grade of 4B, exhibiting a corrosion inhibition efficiency of 80.6 % in a 3.5 wt% NaCl solution.
研究领域:
材料科学
·
电化学
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DOI
高影响因子
COMPOSITES SCIENCE AND TECHNOLOGY
·
2016
·
IF 3.897
Yu Zhao,Nana Li,Shengji Xia
Zn–Al layered double hydroxides (LDH) modified polyamide (PA) nanofiltration (NF) membranes were successfully fabricated by interfacial polymerization of 1,3-Phenylene diamine (MPD) and 1,3,5-Benzenetricarbonyl trichloride (TMC) monomers . Compared to raw PA membranes, the LDH incorporated membranes showed denser PA layers with more leaf-like folds, rather than ridges and valleys, according to images from field emission scanning electron microscopy (FESEM) and atomic force microscope (AFM). Higher hydrophilicity (with the contact angle decreased from 70.33° to 55.66°) and water permeability (with pure water flux enhanced from 6.76 to 9.48 L/m 2 h, measuring approximately 40.2% improvement) were achieved by PA membranes embedded with Zn–Al LDH nanoparticles . The rejection ability of different membranes was evaluated using Aldrich-humic acid (HA) and water from the Huangpu River; the results indicated that PA/LDH membranes exhibited a higher removal efficiency of natural organic matter (NOM). Excitation–emission matrix (EEM) fluorescence spectroscopy was also used in analysing raw natural water and permeate to investigate the removal mechanism toward different types of organic matters; better antifouling properties were observed for modified PA membranes.
研究领域:
环境科学
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材料科学
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DOI
高影响因子
MATERIALS CHEMISTRY AND PHYSICS
·
2022
·
IF 4.778
Zhemin Zou,Jie Wang,Jun Qu,Panfei Dong,Zhigao Xu
The ionic rare earth elements (REEs) was mainly recovered by in-situ leaching process. The concentration of rare earth ions in the leaching solution after long-term leaching process would be too low for traditional precipitation process for REEs recovery. The adsorption process was ideal for the low concentration REEs recovery. In this study, Zn–Al LDH precursor were successfully synthesized by mechanochemical method for the adsorption of REEs (including La − , Eu 3+ and Er 3+ ). X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron energy spectrometer (XPS), and Zeta potential test was applied for adsorption mechanism illustration. The maximum adsorption capacity of the Zn–Al LDH precursor for La 3+ , Eu 3+ and Er 3+ reached 492 mg/g, 346 mg/g, and 1154 mg/g which was significantly higher than other types of adsorbents. The adsorbed REEs on the Zn–Al LDH was hard to be desorbed. The Zn–Al LDH precursor after REEs adsorption could be directly used as high content REEs resources for further process.Therefore, the Zn–Al LDH precursor could be a promising adsorbent for REEs recovery in practical application.
研究领域:
材料科学
·
环境科学
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DOI
高影响因子
ENERGY & FUELS
·
2025
·
IF 5.3
Xiaoteng Cui,Mingsheng Luo,Zhi Yang,Roshni Rahman,Ziyuan Li,Wenshuai Yang,Lingman Xia
As a greenhouse gas, carbon dioxide is also a rich carbon resource that can be effectively utilized to tackle the global warming crisis. This paper presents an in-depth investigation of the impact of the Cu content on the structure of Cu–Zn–Al layered double hydroxides (LDHs) from a novel perspective. The CO2 hydrogenation performance of the derived catalyst, the LDO, is also evaluated in the methanol synthesis reaction. All catalysts were evaluated at 3.0 MPa, a carbon dioxide to hydrogen ratio of 3, and a space velocity of 3600 mL·g–1·h–1. The results from this work indicate that the catalyst with a Cu:Zn ratio of 11:4 exhibited the highest methanol selectivity of 63.9% at 230 °C. At 250 °C, the catalysts also yielded the highest methanol selectivity of 50% only, along with a CO2 conversion as high as 17.8%. In situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) data suggest that the CO2-to-methanol reaction follows the formate (HCOO*) mechanism for this catalyst. Results from this work offer a novel approach to designing Cu-LDH-based catalysts, which offers valuable insights for the efficient chemical utilization of CO2.
研究领域:
化学工程
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环境科学
·
催化材料
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DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2024
·
IF 8.4
Yifan Wang,Tingjuan Wang,Xiaowen Wu,Jiancheng Wang,Endong Chang,Zhaohui Huang,Minghao Fang,Xin Min,Shiming Su
Forward osmosis membrane has shown great potential in the fields of seawater desalination and sewage treatment. However, the concentration polarization phenomenon and membrane fouling in the water treatment process greatly reduce the water treatment performance and restrict its application. To address these challenges, we employed a pre-buried seed-in-situ growth method to facilitate the Zn–Al layered double hydroxide (Zn–Al LDH) growth on the thin nanofiber membrane, and use it as the support layer for the preparation of a Zn–Al LDH modified forward osmosis membrane. Studies have shown that the introduction of Zn–Al LDH significantly improves the water treatment efficiency of the forward osmosis membrane (In Al-DS mode, the water flux increased by 87.5 %, up to 50.50 LMH, with a low specific salt flux of 0.13 g L −1 ). It also exhibits exceptional antibacterial, anti-membrane fouling, and photocatalytic degradation properties. This research presents a novel approach for the development of advanced high-efficiency forward osmosis membranes.
研究领域:
水处理
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膜技术
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环境工程
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材料科学
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DOI
高影响因子
CHEMOSPHERE
·
2021
·
IF 7.086
Jiangfu Zheng,Wenbo Li,Rongdi Tang,Sheng Xiong,Daoxin Gong,Yaocheng Deng,Zhanpeng Zhou,Ling Li,Long Su,Lihua Yang
In this study, an investigation is conducted into the degradation of nitenpyram (NTP) using highly efficient APMMO/PDS/Vis system. As photocatalysts, silver phosphate (AP) and calcined Zn–Al layered double hydroxides (MMO) exhibit high efficiency in achieving charge separation. Besides, the injection of electrons into peroxydisulfate (PDS) from the APMMO can contribute to obtaining the species in the active state with higher efficiency. Based on the APMMO/PDS/Vis system, 50 mg/L of nitenpyram (NTP, 50 mL) can be completely removed in 60 min using 0.8 g/L photocatalyst and 0.2 g/L PDS under the optimum condition and visible light (780 nm > λ > 420 nm). Meanwhile, as demonstrated under visible light within 30 min, an ultrahigh degradation efficiency can be achieved by NTP based on APMMO1/PDS/Vis system. Besides, the electron paramagnetic resonance (EPR) technique and radical quenching experiments suggested 1 O 2 , h + , SO 4 − •, •O 2 − , and •OH are all contributory to the removal of pollutants. Given the outcomes achieved by LC/MS system and mass spectrometry, the primary degradation intermediates of NTP end up being converted into photodegradation products (such as 2-Chloropyridine, 6-Chloropurine Riboside and dl -Leucine). Additionally, there are three potential photodegradation pathways to NTP degradation have been deployed. Moreover, the NTP light degradation occurring in APMMO1/PDS/Vis system is competent under the three types of real water sample. Accordingly, the high-efficiency APMMO1/PDS/Vis system is fit for use in water pollution control for agricultural productions.
研究领域:
环境科学
·
农业科学
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DOI
PubMed
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2018
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IF 3.779
Ziqiang Ai,Changqing Liu,Qiwu Zhang,Jun Qu,Zhao Li,Xiaoman He
In this study, a mechanochemical route to promote the adsorption of the precursor of Zn-Al layered double hydroxide (LDH) was introduced, in which ZnO and SiO 2 were added to Zn basic carbonate and Al hydroxide that were first dry milled into an activated state as a precursor for a LDH phase. The samples prepared in this way were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR) and Scanning electron microscopy (SEM). The precursors showed a high adsorption rate when added with the oxides. 10% addition of ZnO gave a maximum MO removal efficiency of 96.91% (193.82 mg/g at initial MO concentration of 160 mg/L), 16.46% higher than the sample without addition. Addition of SiO 2 at 25% allowed MO removal efficiency reaching 88.90% (222.25 mg/g, at initial MO concentration of 200 mg/L), 19.26% higher than the no additive sample. The improvement in the adsorption performance could be attributed to the effective dispersion of the precursor's agglomeration phenomenon. Discussion was performed based on the characterized features of the samples and fitting results on several adsorption models.
研究领域:
环境科学
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材料科学
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DOI
高影响因子
CELLULOSE
·
2024
·Vol. 31
·期 6
·3517-3531
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IF 4.9
Zhang Shanbei,Chen Zanmei,He Hongwei,Jiang Yijun
The alkali/urea system is an economical and environmentally friendly solvent system for dissolving cellulose. However, the mechanical performance of cellulose derived materials (such as fibres or films) treated with alkali/urea must be improved. The capacity of this system for cellulose dissolution is limited and the mechanical properties of the regenerated cellulose fibres are still unsatisfactory. Here, cotton linter pretreated with peracetic acid (PAA) was dissolved in a LiOH/urea aqueous suspension in which Zn–Al layered double hydroxide (Zn–Al LDH) nanosheets (NS thickness = 3 nm) were exfoliated in situ. After wet spinning, the strength and toughness of the regenerated cellulose fibres reached 290 ± 7.66 MPa and 23.5 ± 4.40 MJ/m 3 respectively, which were 66.7% and 150% higher than those without the LDH NS treatment. It is interesting to note that the synergistic effect of Zn 2+ and Al 3+ distributed on the surface of the LDH host layer significantly improved the solubility of cellulose at low temperature and the interaction between the cellulose and LDH NSs also improved the mechanical performance. This work provides a strategy for improving both the solubility of cellulose in the alkali/urea system and the mechanical properties of regenerated cellulose fibres. Graphical abstract
研究领域:
材料科学
·
化学工程
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
RARE METALS
·
2022
·Vol. 41
·期 8
·2745-2758
·
IF 6.318
Li Pu-Bo,Wang Yong-Xun,Shao Ze-Xi,Wu Bin-Tao,Li Heng,Gao Mang-Mang,Liu Kuan-Guan,Shi Ke-Ren
The Mg–Al layered double hydroxide (LDH) conversion coatings were first synthesized in situ to modify the AZ91D alloy through urea hydrolysis to adjust the pH values (9.4, 10.4, 11.2 and 11.4). The pH 11.2 Mg–Al LDH possessed the best compactness and good crystallinity compared to other in situ LDH coatings and obtained the lowest corrosion current density ( i corr ) of (2.884 × 10 −6 ± 0.345 × 10 −6 ) A·cm −2 , which was attributed to the anion-exchange reaction of LDH and the physical barrier against corrosion owing to the twisted penetration pathway of the interlaced LDH sheets. Core–shell structured Zn–Al LDH@ZIF-8 powder modified with stearic acid (SA) was further wrapped with polyvinylidene fluoride (PVDF) to prepare a hydrophobic double-layered coating on the underlying pH 11.2 Mg–Al LDH (SLLZ). The water contact angle (CA) of the SLLZ coating reached 105.6°, and its i corr decreased to (3.524 × 10 −7 ± 0.214 × 10 −7 ) A·cm −2 compared with a single pH 11.2 film. The SLLZ coating exhibited high durability and corrosion protection, even after 15 days of immersion in NaCl solution. The PVDF, SA and ZIF-8 nano-shells contributed to good hydrophobicity, effectively forming a physical barrier. The Zn–Al LDH core and underlying in situ Mg–Al LDH were beneficial for synergistically promoting anion-exchange reaction between the intercalated anions of LDH and chlorides in corrosive media. This work provides a promising approach that combines core–shell LDH@ZIF-8 with LDH film on a Mg alloy surface to construct a hydrophobic film with excellent long-term anti-corrosion performance. Graphical abstract
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高影响因子
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