INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2016
·
IF 3.205
Yushan Hou,Jianfang Wu,Elena Yu. Konysheva
Quantitative analysis of Cr-adsorption from a gas phase on CeO 2 , pure and doped BaCeO 3 was performed in combination with surface techniques and electrochemical impedance spectroscopy . The Cr-adsorption on BaCeO 3 is 3 times higher than on CeO 2 and it increases by 12–25% on In doping in Ba(Ce 1−x In x )O 3 (x = 0.1–0.3) in the temperature range of 600–700 °C. These perovskites adsorb chromium with the formation of a multi-phase surface layer containing BaCr 6+ O 4 and cerium oxide. Coexistence of small fractions of Cr 3+ and Cr 5+ cations in the surface layer was identified by X-ray photoelectron spectroscopy. The thickness of the surface layer and its morphology vary with temperature, affecting the conductivity of Ce containing perovskites below 700 °C. BaCrO 4 exhibits under air noticeably larger anisotropic thermal expansion than BaCeO 3 . The results indicate that high tolerance to Cr-gaseous species should be considered as an important criterion for further development of materials for proton-conducting SOFCs.
研究领域:
材料科学
·
电化学
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产品关联
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2016
·
IF 2.76
Zhengyang Li,Tingting Li,Libao An,Huan Liu,Linnan Gu,Zhiming Zhang
Chitosan/polycaprolactam (PA6) nanofibrous filter paper (NFP) was prepared by electrospinning technique. Characterization with Fourier transformation infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM) indicated that there was weak interaction (hydrogen bonds) between PA6 and chitosan, and the average diameter of the composite nanofibers decreased as the chitosan content was increased. The maximum adsorption capacity of Cr(VI) on the NFP via filtration (114.7 mg g −1 ) was much higher than that via static adsorption (81.7 mg g −1 ) and shaking adsorption (80.7 mg g −1 ). Because the Cr(VI)-containing solution was forced to flow through the whole membrane in filtration, the chelation sites inside the membrane could be exploited, leading to the enhancement of the Cr(VI) adsorption. The hydrogen bonds between chitosan and PA6 could enhance the mechanical strength and the acid fastness of the NFP. Therefore, the NFP desorbed by H 2 SO 4 can be well reinstated, and the adsorption capacity of Cr(VI) decreased slightly (only 17.9%) after three filtration cycles. On the basis of X-ray photoelectron spectroscopy (XPS) analysis, the possible mechanism for the Cr(VI) removal was that Cr(VI) was initially adsorbed on the NFP due to the electrostatic attraction, and subsequently reduced to the less toxic form Cr(III) by the amino groups of chitosan.
研究领域:
材料科学
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环境科学
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生物医学工程
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DOI
高影响因子
JOURNAL OF POLYMER RESEARCH
·
2017
·Vol. 24
·期 3
·1-11
·
IF 1.615
Wang Ning,Chen Yang,Ren Jianyu,Huang Xiongyi,Chen Xueyan,Li Guodong,Liu Dongqin
Dodecylbenzene sulfonic acid (DBSA) doped-polyaniline (PANI) coated conductive polyimide (PI) microfiber membrane was prepared by chemical oxidation polymerization. PI nanofiber membrane was prepared by solution blowing. Fourier transform infrared spectra (FTIR), X-ray photoelectron spectroscopy (XPS) and scanning electron microscope (SEM) proved that the successful preparation of composite microfiber membrane with core-shell structures. At the same time, the PANI had an effect of protection on PI nanofiber, which was detected by thermal gravimetric analysis (TGA). The orthogonal experiments were designed to determine the optimal reaction conditions for the conductivity of PANI/PI microfiber membranes as following: ANI concentration (0.15 mol L −1 ), APS concentration (0.1 mol L −1 ) and DBSA concentration (0.3 mol L −1 ). The conductivity of PANI/PI microfiber membranes could arrive to 3.83 × 10 −2 S cm −1 . Moreover, the PANI/PI microfiber membranes had a superior hexavalent chromium (Cr (VI)) adsorption performance. The factors affecting the performance of hexavalent chromium (Cr (VI)) removal from the aqueous solutions were investigated.
研究领域:
材料科学
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高分子化学
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环境工程
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纳米技术
✓ 已验证
DOI
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
·
2023
·
IF 9.8
Huimin You,Changlin Cao,Xiaoli Sun,Baoquan Huang,Qingrong Qian,Qinghua Chen
Microplastics (MPs) are emerging contaminants with growing concerns due to their potential adverse effects on the environment. However, understanding the aging properties and adsorption behavior of MPs is still limited. In this study, we investigated the correlation between the adsorption capacity, aging stages, and aging properties of polyethylene MPs using a correlation equation. Our results revealed that the trends of O/C ratio and contact angle of polyethylene MPs with aging time were fitted to be linear under xenon lamp accelerated aging conditions. Conversely, the trends of other properties such as particle size, crystallinity , and molecular weight with time were fitted to conform to the Boltzmann equation. Moreover, the aging curve data for carbonyl index and molecular weight (M w ) perfectly matched, confirming M w play a crucial role in verifying the aging process. Additionally, the adsorption amount of polyethylene MPs increased sharply with the increase of aging ages, reaching up to 1.850 mg/g. The adsorption data fit well to the pseudo-second-order kinetics and Langmuir model, suggesting that the adsorption process is dominated by chemisorption . The low pH and low salt concentration is beneficial to the adsorption capacity of MPs onto Cr(VI). Further, a relationship equation was established to predict adsorption risk at different aging stages. These findings provide new insights into the impact of aging on pollutants transport and the fate of MPs, enabling the prediction of adsorption risk of MPs at different aging stages in water environments.
研究领域:
环境科学
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材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Processes
·
2024
·Vol. 12
·期 11
·2598
·
IF 2.8
Xiaofei Li,Tianfu Li,Xiaohu Jin,Yanfu Wei,Yanping Bao,Qian Yao,Fuhua Li,Weicheng Xu,Xiaolian Wu
The adsorption of toxic metals onto iron oxides is a prevalent geochemical process in natural environments. Organic acids are known to modify the adsorption features of toxic ions through either competitive or cooperative effects. Nowadays, the toxic metal adsorption influenced by organic acids on iron oxides with varying facet exposures is not fully understood. This study explored how L-Aspartic acid (LA) influences Cr(VI) adsorption on two different exposure facets of lepidocrocite through batch adsorption experiments, in situ ATR-FTIR spectroscopy, and 2D-COS analysis. The results reveal that LA competes for available binding sites on lepidocrocite, consequently inhibiting the adsorption of Cr(VI). Rod-shaped lepidocrocite (R-LEP) owns more (001) facets and shows stronger Cr(VI) adsorption and LA competition than plate-like lepidocrocite (P-LEP), which mainly has (010) facets. The data for Cr(VI) uptake on both P-LEP and R-LEP within the effect of LA are well-fitted by the pseudo-second-order kinetics and the Freundlich isotherm model, suggesting chemical interaction as the dominant process for Cr(VI) coordination on lepidocrocite. Cr(VI) ions favor interaction with R-LEP over P-LEP, forming inner-sphere complexes on (001) facets. Concurrently, LA’s carboxyl groups can compete for the active sites on the lepidocrocite surfaces, engaging in anion exchange with hydroxyl groups, and forming outer-sphere and inner-sphere structures. This competitive effect is particularly pronounced in the R-LEP system. The current findings are expected to broaden insights into how the exposed facets of lepidocrocite influence the fate of Cr(VI) in the organic acid coexistence environment.
研究领域:
环境科学
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化学
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产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
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2017
·
IF 3.671
Tianyi Zhu,Wei Huang,Lingfan Zhang,Jie Gao,Wenqing Zhang
In this work, cerium immobilized cross-linked chitosan (CTS-Ce) composite, employed as an efficient adsorbent for Cr(VI) in single system and coexisted with Orange II (OII) in binary system, was prepared by co-precipitation method. The as-obtained adsorbent was characterized by FTIR, SEM, EDS and XPS before and after adsorption. The adsorption behaviors of Cr(VI) in single and binary system were systematically studied. The maximum adsorption capacity of Cr(VI) on CTS-Ce (202.8 mg/g) was calculated by Langmuir equation in single metal system, but it decreased to 112.9 mg/g with initial concentration of 100 mg/L OII in binary system at pH 2 and 293 K. The adsorption data for Cr(VI) followed the Langmuir model in single system, while fitted Temkin model well in binary system. In both single and binary system, the kinetics of adsorption exhibited pseudo-second order behavior and adsorption capacity increased with increasing temperature. Moreover, the data of thermodynamic parameters ( ΔG° < 0, ΔH° > 0) indicated that the adsorption was a spontaneous and endothermic process. Besides, | Δ G C r | > | Δ G C r − O I I | at the same temperature further suggested that Cr(VI) was adsorbed on the CTS-Ce composite faster in binary system than in single system.
研究领域:
环境科学
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材料科学
✓ 已验证
DOI
PubMed
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2021
·
IF 4.539
Ruibin Guo,Wei Guo,Hebing Pei,Bingjie Wang,XuDong Guo,Nijuan Liu,Zunli Mo
Chromium (Cr (VI)) is one of the heavy metals that seriously endanger human health and the environment. It is a huge challenge to develop high-efficiency adsorbents with low cost, simple preparation method and green production technique and zero pollution to the environment. In this work, electrospinning technology was used to prepare polyacrylonitrile/polyethyleneimine (PAN/PEI) electrospinning nanofiber membranes (ENM), and then polyacrylonitrile/polyethyleneimine/polypyrrole (PAN/PEI/Ppy) composite nanofiber membrane (CNM) was successfully synthesized by chemical depositing polypyrrole (Ppy) on the surface of PAN/PEI ENM. PAN/PEI ENM provided a larger specific surface area, which facilitated better and more uniform deposition of Ppy on the surface of nanofiber membranes. Scanning electron microscope (SEM) and transmission electron microscope (TEM) images showed that the prepared PAN/PEI/Ppy CNM looked like "balsam pear", and had high adsorption capacity of Cr (VI), with a maximum adsorption capacity of 368 mg g -1 . After five times of adsorption-desorption, the removal of Cr (VI) reached more than 95%. More importantly, compared to the current complex chemical synthesis of Cr (VI) ion adsorbents and secondary pollution to the environment, electrospinning fully demonstrates the huge technical advantages of industrial applications, including high efficiency, simple preparation, and green (no harmful chemical by-products), low cost, no secondary pollution. PAN/PEI/Ppy CNM will be promising solid adsorbent candidates for the removal of Cr (VI) ions in wastewater.
研究领域:
环境科学
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材料科学
✓ 已验证
DOI
高影响因子
CHEMOSPHERE
·
2022
·
IF 8.943
Wei Mao,Ying Zhang,Jinen Luo,Lingtiao Chen,Yuntao Guan
It is still a huge challenge to prepare cheap and effective composite materials for removing hexavalent chromium (Cr(VI)) in sewage treatment . In this study, a noval co-polymerization of polypyrrole/polyaniline on ferrate modified biochar (Ppy/PANI/FBC) was fabricated via ferrate-promoted pyrolysis and in-situ oxidative polymerization of pyrrole and aniline molecules to effectively remove Cr(VI) from polluted water. The Ppy/PANI/FBC quickly decreased Cr(VI) concentration from 38.92 to 3.92 mg/L within 400 min, with an efficient removal efficiency (89.92%), which was significantly higher than that of FBC (4.75%), Ppy/FBC (72.30%), and PANI/FBC (42.43%). These results are mainly caused by its conjugated connection and well-dispersion of Ppy and PANI on the surface of a carbon-based material. Meanwhile, the experimental results were in line with the pseudo-second-order kinetic and Freundlich models. The Ppy/PANI/FBC is featured by a high capacity of Cr(VI) adsorption (up to 203.71 mg/g). In addition, it could be adopted for efficiently removing Cr(VI) over a wide pH range (4–9) because of the positively charged nitrogen (–NH .+ – and = N + –). The sorption mechanisms of Cr(VI) were identified, including electrostatic interaction with surface protonated nitrogen (N + ), ion exchange between the doped Cl − ions and Cr(VI), chemical decrease of the Cr(VI) to Cr(III) by the iron valence cycle and efficient electron transfer of Ppy/PANI/FBC, as well as surface complexation by amine and oxygen-containing groups. More importantly, 97.98% Cr(VI) was efficiently removed in 20 min by coupling a photocatalytic reaction, also providing a novel idea for the practical use of adsorbents in wastewater treatment .
研究领域:
环境科学
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材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
·
2022
·
IF 10.753
Qian Zhu,Huiqin Gao,Yiwei Sun,Yujia Xiang,Xiangjing Liang,Andrei Ivanets,Xiaoqin Li,Xintai Su,Zhang Lin
The synergistic effect of heteroatoms is a viable method to enhance the adsorption performance of heavy metal onto carbon-based materials. However, the high cost, complex operation and a lot of pollution from the synthesis process have limited its development. Herein, a facile two-step pyrolysis method is used to prepare in situ N and S doped porous biochar from paper mill sludge for the removal of Cr(VI) from aqueous environment. The NSC-450 sample prepared under the optimum conditions has a large specific surface area of 3336.7 m 2 g −1 , an average pore size of 2.56 nm and a total pore volume of 2.10 cm 3 g −1 , manifesting the excellent adsorption capacity of 356.25 mg g −1 for Cr(VI). The adsorption of Cr(VI) by NSC-450 is consistent with the Langmuir isotherm and pseudo-second-order model, suggesting a spontaneous and endothermic chemisorption process. The analysis results show that the NH, graphitic nitrogen and thiophene structures have a positive effect on converting a large amount of Cr(VI) to Cr(III) by synergistic reduction, indicating obviously facilitating Cr(VI) removal compared to other sites. Therefore, in this material, the strong adsorption mechanism is mainly reductive complexation. Moreover, the effects of real water quality, anions, cations and fulvic acid on the adsorption behavior of Cr(VI) onto the NSC-450 were further investigated. The results demonstrate that the chromium removal rate remains above 82% even in actual electroplating wastewater, suggesting NSC-450 has great practical application prospect. This work offered a feasible method for high-value utilization of sludge, but also provided a novel perspective for the future design of heteroatom-doped carbon materials for promoting to eliminate hexavalent chromium from water environment.
研究领域:
环境科学
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材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Processes
·
2025
·Vol. 13
·期 1
·156
·
IF 2.8
Ting Guan,Liang Fang,Fang Wu,Yongxia Yang
NiFe-layered double hydroxide (NiFe-LDH) and La-, Mo- or W-doped NiFe-LDH microparticles (NiFeX-LDH, X = La, Mo, W) were synthesized via the co-precipitation method. Their adsorption characteristics were evaluated by the removal of methyl orange (MO) and hexavalent chromium (Cr6+). The effects of the metal ion doping type, doping concentration (0–3at%), pH and temperature on the MO adsorption properties were systematically studied. The results show that W-doped NiFe-LDH exhibits superior MO removal capacity compared to undoped or La- or Mo-doped NiFe-LDH at the same 1at% doping level, which is attributed to the increased layer charge density and strong affinity for the π-electron systems of MO molecules. The NiFeW-LDH-1at% sample demonstrated the best MO adsorption performance within the W-doping range of 0–3at%, achieving a superior adsorption capability of 666.67 mg/g with a significantly shorter equilibrium time (10–120 min) compared to the similar LDH. NiFeW-LDH-1at% showed promising reusability, with its adsorption efficiency remaining 78.3% of its initial level after five adsorption–desorption cycles. The MO uptake onto NiFeX-LDH was attributed to the combined effect of anion exchange and the attraction of layer charge. In addition, the adsorption of NiFeW-LDH-1at% matched well with the Langmuir isotherm model and pseudo-second-order kinetic model, indicating a monolayer and chemical adsorption. Furthermore, NiFeW-LDH-1at% effectively adsorbed of Cr2O72−in the aqueous solution, revealing that W doping significantly enhances Cr(VI) removal performance. The maximum theoretical adsorption capacity onto NiFeW-LDH-1at% reached 63.25 mg/g, which was notably higher than that of the pristine NiFe-LDH adsorbent (53.56 mg/g). Overall, the W-doped NiFe-LDH material, as a low-cost and highly efficient adsorbent, shows great potential for wastewater treatment application.
研究领域:
材料科学
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2019
·
IF 7.65
Zhiwei Wang,Yahuan Wang,Shuai Cao,Shaohua Liu,Zhimin Chen,Jiafu Chen,Yong Chen,Jianwei Fu
The rational design of novel adsorption materials is imperative to remove toxic metal species from the polluted water. Herein, a core@shell structural Fe-Fe 2 O 3 @poly (hexachlorocyclotriphosphazene-co-polyethylenimine) (Fe-Fe 2 O 3 @PHCP) magnetic nanochain with high saturation magnetization was fabricated and used for effective adsorption and reduction of hexavalent chromium. The morphology and microstructure of Fe-Fe 2 O 3 @PHCP were characterized by scanning electron microscopy, transmission electron microscopy , Fourier transform infrared spectroscopy , X-ray diffraction and X-ray photoelectron spectroscopy. The effects of concentration, pH, contact time, temperature and coexisting ions on Cr (VI) removal were studied. Four kinetic models (pseudo-first-order, pseudo-second-order, Bangham and intraparticle diffusion models) and two isotherm models (Freundlich and Langmuir) were used to fit experimental data. Results show the adsorption capacity of Fe-Fe 2 O 3 @PHCP for Cr (VI) is up to 229.0 mg g −1 . The excellent performance was ascribed to the favorable reduction of Cr (VI) to Cr (III), followed by the chelation of Cr (III) with imino groups. Meanwhile, the residual Cr (VI) were adsorbed on protonated amino and imino groups. The adsorption process is exothermic and spontaneous and nicely follows pseudo-second-order kinetics, intraparticle diffusion model and Langmuir isotherm model. These results indicated that easily separable Fe-Fe 2 O 3 @PHCP magnetic nanochains could be a promising adsorbent to remediate chromate wastewater.
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
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2019
·
IF 3.375
Qian Chen,Yi Feng,Rongrong Tian,Jinghang Chen,Anqing Wang,Jianfeng Yao
Photosensitization is a promising way to make UiO-66 visible light responsive. In this work, zirconium (Zr) precursors and synthetic methods (solvent-assisted or nonsolvent-assisted) were found to significantly affect the electric charge and the defect sites of UiO-66. UiO-66 with enhanced adsorption and photosensitized photocatalytic ability was then obtained. When ZrOCl2·8H2O was applied as Zr-precursor in a nonsolvent method, defect rich UiO-66 (UiO–OCl–N) was achieved with higher Cr(VI) adsorbing ability and improved photosensitized photocatalytic ability. Moreover, with the coexistence of Rhodamine B in Cr(VI) solution, photocatalytic performance of UiO-66 can be further enhanced.
研究领域:
材料科学
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环境科学
·
化学工程
✓ 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）