CHEMOSPHERE
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2019
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IF 5.108
Kun Wang,Yuebing Sun,Jingchun Tang,Juan He,Hongwen Sun
A novel ball milled Fe 0 -biochar composite was synthesized by ball milling the mixture of biochar (pyrolyzed at 300 °C, 500 °C, and 700 °C) and micron grade iron powder. FTIR, SEM , TEM-EDS, XRD , and XPS were applied to characterize this composite. XRD results showed that iron carbide phase was formed during the ball milling process. The ability of this synthesized composited to remove aqueous Cr(VI) was tested. Removal rates of Cr(VI) (49.6%, 65.8%, and 97.8%, respectively) by ball milled Fe 0 -biochar composite consisting of biochar pyrolyzed at 300 °C (300BMFe 0 -BC), 500 °C (500BMFe 0 -BC), and 700 °C (700BMFe 0 -BC) were much higher than those (19%, 11%, and 4%, respectively) by pristine biochar pyrolyzed at 300 °C (300BC), 500 °C (500BC), and 700 °C (700BC). Cr(VI) removal rate by 700BMFe 0 -BC increased from 15.4% to 97.8% when prolonging ball milling time from 6 h to 48 h. Ball milling promoted the combination of Fe 0 and biochar as well as reduced the hydrodynamic diameter of the composite. Acidic conditions favored Cr(VI) removal. Ball milling exposed the functional groups of biochar and improved its Cr(VI) removal rate. Raman spectra showed that the degree of graphitization in 700 °C ball milled biochar (700BMBC) was the highest. Electrochemical analysis demonstrated that 700BMBC had the highest electron transfer capacity. In the presence of Fe 0 , graphitized structure in 700BMBC acted as an electron conductor, facilitating electron transfer from Fe 0 to Cr(VI). Ball milling also destroyed the surface iron oxide layer to regenerate the composite.
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PubMed
高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
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2019
·Vol. 26
·期 11
·11126-11139
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IF 2.914
Li Zhenyuan,Pan Zhidong,Wang Yanmin
A raw illite-smectite mixed-layered clay (RI/S) was ground for preparing nano-sized I/S clay (NI/S) and subsequently amino-functionalized via grafting of 3-aminopropyltrithoxysilane (APTES) (NH 2 -RI/S and NH 2 -NI/S, respectively). The samples were characterized by particle size analysis, specific surface area measurement, X-ray diffraction (XRD), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR), and 29 Si nuclear magnetic resonance ( 29 Si NMR). Compared to RI/S, NI/S has a narrow particle size distribution and appears in a platelet-like morphology due to the disintegration/exfoliation of RI/S after grinding. Based on the 29 Si NMR spectra, the appearances of tri-silicate units indicate the chemically grafting of APTES molecules on NH 2 -RI/S and NH 2 -NI/S, respectively. NH 2 -NI/S can adsorb greater amounts of Pb(II) cations and Cr(VI) anions rather than NH 2 -RI/S since NH 2 -NI/S grafts more amounts of amine groups (-NH 2 ). The isotherm data for adsorption of Pb(II) cations and Cr(VI) anions can be described by the Langmuir model at different temperatures (i.e., 10 °C, 30 °C, and 50 °C), respectively. The maximum adsorption amounts of Pb(II) cations and Cr(VI) anions onto NH 2 -NI/S calculated by the Langmuir isotherm model are 131.23 mg/g and 36.91 mg/g at 50 °C, respectively. The adsorptions of Pb(II) cations and Cr(VI) anions onto NH 2 -NI/S involve in the surface complexation of NI/S and amine groups.
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高影响因子
MATERIALS SCIENCE IN SEMICONDUCTOR PROCESSING
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2019
·
IF 2.722
Xinbo Jing,Xueying Peng,Xiyin Sun,Wu Zhou,Wei Wang,Shufen Wang
In this study, a facile impregnation-calcination strategy was applied in order to synthesize Mo2C modified MoO3 (Mo2C/MoO3), which was then employed as catalyst for the photoreduction of Cr (VI) and photodegradation of methyl orange (MO) upon irradiation by visible light (λ > 400 nm). The apparent rate constant (k) of Mo2C/MoO3 for the MO photocatalyzed degradation reaction under visible-light irradiation was found to be 0.0171 min-1, which was 4.59 and 67.38 times higher than that of Pt/MoO3 and pristine MoO3, respectively. Study of the photocatalytic mechanism revealed that the •O2- species played a major role in MO degradation. Moreover, the addition of Mo2C enhanced the light response region of MoO3, and also promoted the photocatalytic activity of MoO3. This was due to the enhanced separation efficiency of photogenerated electron-hole pairs and broader photoresponse region. This work suggests a new use for the easily accessible Mo2C/MoO3 heterostructure and could facilitate the application of photocatalysts for wastewater treatment．
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高影响因子
ACS Applied Nano Materials
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2019
·
IF 0
Yi Feng,Qian Chen,Mengjue Cao,Nan Ling,Jianfeng Yao
Defect engineering and surface chemistry are closely related to the performance of materials. In this work, the effects of Zr precursors and Ti substitution on the photocatalytic performance of UiO-66-NH2 are studied and analyzed from the perspective of defect engineering and surface chemistry. The findings show that when using ZrOCl2·8H2O as the Zr precursor combined with the postsynthetic treatment of Ti substitution, sample U-OCl-Ti shows significant improvement in Cr(VI) adsorption (20.9 mg/g) and photocatalytic reduction of Cr(VI) under visible light. The improvement can be attributed to the highly defective framework and more -NH2 groups exposed on the surface; therefore the highest light absorption and lowest recombination rate of photogenerated electron–hole pairs are observed in U-OCl-Ti. The findings in this study contribute to a better understanding of how defects and surface chemistry affect the photocatalytic performance, thus providing some designing knowledge for the synthesis of UiO-66 or UiO-66-NH2 with high photocatalytic performance.
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SEPARATION AND PURIFICATION TECHNOLOGY
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2018
·
IF 3.927
Xiangyu Wang,Tao Wang,Jun Ma,Huiling Liu,Ping Ning
A novel composite based on hydrophilic boehmite-PVB/PVDF blended membrane- immobilized nanoscale zero-valent iron (nZVI) (BPPN) was synthesized. When the initial concentration of Cr(VI) was 20 mg/L, 100% Cr(VI) was removed by BPPN at an initial pH of 4.08 under room temperature of 25 °C within 90 min. In addition, the reactivity of the regenerated BPPN composites toward Cr(VI) removal were not obviously declined after 6 cycles. The resultant BPPN demonstrated high reactivity, preeminent stability and reusability in the reaction course. Meanwhile, the BPPN composites showed a higher removal efficiency toward the removal of Cr(VI) compared with alumina-PVB/PVDF-nZVI (APPN) composites. The plentiful hydroxyl groups of boehmit on the BPPN surface resulted in the enhancement in hydrophilicity and improved Fe 0 loading of the BPPN composites. For environmental parameters, results indicated that there was a negative effect of increasing the initial concentration or decreasing reaction temperature toward the removal of Cr(VI) by BPPN, and that the acidic and neutral conditions showed more favorable effect on Cr(VI) removal than the alkaline ones. The generated ferrous ions on the surface of BPPN were certified to play an important role in removal of Cr(VI). XPS analysis suggested that the reduction reaction of Cr(VI) occurred on the surface of the composite and produced precipitation of Cr(III). The Cr(VI) removal by BPPN composite was found to follow a revised kinetics well. This study suggests that the novel BPPN composite possessing excellent performance may be a promising functional material of heavy metal wastewater treatment.
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高影响因子
CARBOHYDRATE POLYMERS
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2018
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IF 5.158
Shuping Wu,Xiangzi Dai,Tingting Cheng,Songjun Li
A sensitive and selective electrochemical sensor based on ion-imprinted chitosan-graphene nanocomposites (IIP-S) has been developed for the determination of Cr(VI). The ion-imprinted polymers were constructed by one-step electrodeposition. The morphology and structure of IIP-S were characterized by SEM, TEM , XRD, FTIR and EDS , respectively. Meanwhile, the electrochemical behavior of IIP-S was investigated using CV , EIS and DPV . The linear range of IIP-S was from 1.0 × 10 −9 to 1.0 × 10 −5 mol/L, with the low detection limit of 6.4 × 10 −10 mol/L (S/N = 3). The sensor exhibited high selectivity for the determination of Cr(VI) in the presence of Zn(II), Co(II), Cu(II), Ni(II), Mn(II), MnO 4− , C 2 O 4 2− , S 2 O 6 2− and MoO 4 2− ions. The IIP-S also provided excellent stability and good repeatability that the sensitivity remained 85% after 9 cycles of rebinding-removal, while the sensitivity retained 87% of its initial response storing at 4 °C for 17 days. Moreover, it was successfully applied to the detection of Cr(VI) ions in tap water and river water.
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高影响因子
ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY
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2018
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IF 3.974
Peng Chen,Na Geng,Dong Zhou,Yiran Zhu,Yuliang Xu,Kangping Liu,Yongxia Liu,Jianzhu Liu
Hexavalent chromium (Cr(VI)) is a common environmental pollutant. Exposure of Cr(VI) can lead to cell autophagy, but the preventive measures for diminishing Cr(VI)-induced autophagy need further study. COX-2 can be induced by several heavy metals and can lead to endoplasmic reticulum (ER) stress and autophagy; thus, COX-2, ER stress, and autophagy may be related. This study mainly investigated the role of COX-2 in the eIF2α-ATF4 pathway, which is a major pathway in cell autophagy. In this study, Cr(VI) was used as a xenobiotic to determine changes in the parameters of ER stress, autophagy, and COX-2 levels. At the same time, a clear contrast was obtained by assigning positive and negative controls of ER stress and autophagy. The results showed that during Cr(VI) invasion, the parameters of ER stress and autophagy (such as BiP, PERK, p62, LC3-II, and mTOR) were enhanced, similarly to the positive control of ER stress and/or the autophagy controls. Such enhancement is a protective mechanism for cell survival. Additionally, the COX-2 levels increased. Moreover, when COX-2 was inhibited, the PERK level remained high, whereas the LC3-II level decreased. This finding suggests that COX-2 specifically affects the interaction between ER stress and autophagy. Notably, this study reveals that Cr(VI) can induce ER stress and autophagy in DF-1 cells and that COX-2 plays an essential role in the interaction between ER stress and autophagy.
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高影响因子
TALANTA
·
2013
·
IF 3.498
Hong-mei Jiang,Ting Yang,Yan-hong Wang,Hong-zhen Lian,Xin Hu
A new approach of magnetic solid phase extraction (MSPE) coupled with graphite furnace atomic absorption spectrometry (GFAAS) has been developed for the speciation of Cr(III) and Cr(VI) using zincon-immobilized silica-coated magnetic Fe 3 O 4 nanoparticles (Zincon–Si–MNPs) as the MSPE absorbent. Cr(III) was quantitatively reserved on the absorbent at pH 9.1 while total Cr was reserved at pH 6.5. The absorbed Cr species were eluted by using 2 mol/L HCl and detected by GFAAS. The concentration of Cr(VI) could be calculated by subtracting Cr(III) from total Cr. All the parameters affecting the separation and extraction efficiency of Cr species such as pH, extraction time, concentration and volume of eluent , sample volume and influence of co-existing ions were systematically examined and the optimized conditions were established accordingly. The detection limit (LOD) of the method was 0.016 and 0.011 ng mL −1 for Cr(III) and Cr(VI), respectively, with the enrichment factor of 100 and 150. The precisions of this method (Relative standard deviation, RSD, n =7) for Cr(III) and Cr(VI) at 0.1 ng mL −1 were 6.0% and 6.2%, respectively. In order to validate the proposed method, a certified reference material of environmental water was analyzed, and the result of Cr speciation was in good agreement with the certified value. This MSPE–GFAAS method has been successfully applied for the speciation of Cr(III) and Cr(VI) in lake and tap waters with the recoveries of 88–109% for the spiked samples. Moreover, the MSPE separation mechanism of Cr(III) and Cr(VI) based on their adsorption–desorption on Zincon–Si–MNPs has been explained through various spectroscopic characterization.
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高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2024
·
IF 8.1
Jinshan Xie,Xiaoxiang He,Kexin Liu,Wulong Li,Zhanxiong Li
In this paper, carboxylated cotton fabric (CF-Ph-COOH) were obtained as active substrate by diazonium radical polymerization modification of cotton fibers. Then the MOF fabric composites were prepared by in situ growth of metal zirconium ions (Zr) and organic ligands on the surface of carboxylated cotton fabrics under carboxylic acid modifier. MOF fabric composites with controllable morphologies structures were achieved by regulating organic ligands, reaction time the type and dosage of regulator (formic acid and acetic acid). The prepared acetic acid regulated MOF fabric composites were designated as CF-HAc1-UiO-66, CF-HAc2-UiO-66, CF-HAc1-UiO-66-NH 2 , and CF-HAc2-UiO-66-NH 2 , respectively, and the formic acid regulated as CF-FA-UiO-66 and CF-FA-UiO-66-NH 2 . The fabricated carboxylic acid modulated MOF fabric composites were well characterized using SEM, TGA, XRD, FTIR, and XPS spectra. The adsorption experiment results show that carboxylic acid modulated Zr based MOF fabric composites can serve as adsorbent for effective removal of Cr(VI) from water, in which the CF-FA-UiO-66-NH 2 was prepared under the ratio of ZrCl 4 and BDC-NH 2 is 1.006 and with 5.47 M formic acid regulator exhibits that the optimal adsorption efficiency and the removal efficiency is 79.5 %. In addition, the adsorption of Cr(VI) in water by CFA-UiO-66-NH 2 showed a quasi-secondary kinetic model following the Langmuir adsorption model, showing a a typical of chemisorption. What’s more, the Cr(VI) removal efficiency and saturated adsorption capacity of CF-FA-UiO-66-NH 2 was up to 80 % and 318.85 mg/g, respectively. The prepared CF-FA-UiO-66-NH 2 MOF fabric composite was recyclable for removal of Cr(VI), and could be used as the potential adsorbent membrane for waste water treatment.
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高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2025
·
IF 9
Shiyu Zhang,Li Li,Zhiwei Zhao,Yu Li,Li Shen,Sai Zhang
Biochar, being a cost-effective material, is widely used for water pollution control. However, the further degradation of most contaminants is limited due to the weak electron donor properties of raw biochar. Herein, we combined banana peel biochar with microscale zero-valent aluminum (mZVAl) using ball milling technology and demonstrated the effective chromium removal by the composite. Nearly complete removal of Cr(VI) could be achieved within 30 mins, alongside an impressive efficiency of 98.08% in total Cr elimination. Multiple parameters, including water matrices, composite ratio (m mZVAl /m biochar ), and initial solution pH, were explored. Additionally, detection of Cr species revealed that aqueous Cr(VI) was reduced to Cr(III) via chemisorption, followed by the formation of Cr(OH) 3 , which adhered to the surface of the composite. Structural analysis showed that the pristine mZVAl deformed into the plate-like structure under mechanical forces, with biochar distinctly embedded in the mZVAl matrix, increasing lattice spacings. Mechanistic studies suggested that mZVAl acted as the ‘electron donor’, while biochar functioned as the ‘electron shuttle’, accelerating electron transfer through galvanic cell structures. This study clarifies the electron-dominated mechanism in Cr(VI) removal and provides technical support for heavy metal elimination.
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高影响因子
JOURNAL OF RARE EARTHS
·
2024
·
IF 5.2
Chen Di-Ming,Han-Dong Qiao,Shao-Ming Fang
Introduction of porosity and fluorescent properties into lanthanide metal–organic frameworks (MOFs) with rational design to achieve multifunctional use is of great significance from the energy and environmental viewpoint. In this study, a microporous Tb(III)-based MOF with the formula of {[Tb 2 (oba) 3 (Phen) 2 ](DMF) 2 (H 2 O) 4 } n ( 1 ) was solvothermally prepared via using the mixed ligands of 1,10-phenanthroline (Phen) and 4,4′-oxybis(benzoic acid) (H 2 oba) as organic connecters. The structural evaluation results indicate that complex 1 is composed of binuclear Tb 2 (CO 2 ) 6 (Phen) 2 clusters which are extended by the oba 2− ligands to afford a two-fold interpenetrated framework with one-dimensional microporous channels along the b -axis. Gas sorption studies show that the activated 1 demonstrates a high ideal adsorption solution theory (IAST) sorption selectivity of 7.4 toward C 2 H 2 in a C 2 H 2 /CO 2 gas mixture, which are further supported by the dynamic breakthrough experiments. The grand canonical Monte Carlo (GCMC) simulation results indicate that the synergistic effects of the H-bond interactions of C 2 H 2 with oba 2− ligands and the C–H···π interactions with Phen ligand contribute to the strong binding of the framework toward C 2 H 2 molecules. What's more, the luminescent measurements reveal that the emission of 1 features both the characteristic peaks of Phen ligand and Tb(III) ion, which could be further applied as a self-calibrating sensor for the Cr(VI) detection in water. To the best of our knowledge, complex 1 represents the first example of Tb-MOF holding such a high C 2 H 2 /CO 2 selectivity together with ratiometric Cr(VI) detection performances.
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高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Sijia Li,Chaowen Chen,Hongjian Ge,Xinyue Guo,Huan Xu,Jia Zhang,Zhengyan Wu
To eliminate trace toxic hexavalent chromium (Cr(VI)) from water with different pHs, researchers focused on adsorption, reduction of Cr(VI) to trivalent chromium with followed precipitation while the complex and costly reactivity regulations via adjusting pHs was inevitable. Here we exploit Fe-Cu nanocomposites (CnZVI/Cu) with galvanic reactions and engineered nanoconfinement effect for removing Cr(VI) from acidic/alkaline water directly, consisting of phosphorylated cracked nanoscale zero-valent iron (CnZVI, crack width of 1–2 nm) anode and Cu aggregates cathode. The formed primary battery exhibits strong electrostatic interactions towards ions and outstanding reactivity of reduction and precipitation at acidic/alkaline conditions. The pH inside the cracks at neutral or alkaline conditions is calculated to turn lower for enhancing the dynamics relevant to remediation. Benefiting from those two effects, the removal efficiencies of Cr(VI) through CnZVI/Cu attain more than 99.5 % at pH ≤ 8 and even 96 % at pH of 12 in only 30 min, outperforming the previous works. Its protection on beings (water spinach, zebrafish, and cell) from suffering poisonous Cr(VI), control of adsorbed Cr from migration, and magnetic collectability demonstrate the admirable removal performance, biosafety, and stability, respectively. This work proposes highly-efficient, eco-friendly, convenient, and low-cost technology to scavenge Cr(VI) from acidic/alkaline water.
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高影响因子
危险品化学品经营许可证（带存储）