Journal of Environmental Chemical Engineering
·
2023
·
IF 7.7
Jianle Wang,Xueming Liu,Hong Deng,Dongye Zhao,Qiulin Yang,Zhihua Zhu
Various sulfur- and iron-bearing materials have been shown promising for reductive immobilization of Cr(VI) in water and soil. Yet, composite Ca-Fe-S materials and the effects of water chemistry and material aging have not been investigated. In this work, we prepared a type of Ca-Fe-S microparticles under the atmospheric conditions through a facile one-pot approach, and tested the particles for reductive immobilization of Cr(VI) in solution and soil. Ca-Fe-S showed 40 % higher removal efficiency of Cr(VI) in solution than FeSO 4 and 10 % higher than CaS x on the basis of equal molar dosage. When a Cr-laden soil was amended by Ca-Fe-S, the leachable concentration of Cr per the toxicity characteristic leaching procedure remained below the regulatory limit of 5 mg L −1 after 730 days of curing, while FeSO 4 and CaS x failed to meet the regulatory threshold. Ca-Fe-S served as a slow-releasing source of Fe 2+ and S 2- , which were able to convert Cr(VI) into the stable final product of Cr(OH) 3 . Ca-Fe-S was able to perform well under a wide range of pH (3.0–9.0) and in the presence of high concentrations of coexisting ions (5 mmol L −1 of Cl - , SO 4 2- , or HCO 3 - ). Moreover, the material remained effective when aged under the atmospheric conditions for 14 days. This study showed that Ca-Fe-S is a highly effective material for efficient sequestration of Cr(VI) in soil and groundwater under various water chemistry and materials aging conditions.
研究领域:
环境科学
·
土壤化学
·
地下水污染治理
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产品关联
DOI
高影响因子
JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY
·
2020
·Vol. 20
·期 3
·1660-1669
·
IF 1.134
Deng Yu-Ying,Xiao Xin-Feng,Wang Dan,Han Bo,Gao Yu,Xue Jian-Liang
Cu-BTC was synthesised by hydrothermal method in this study to adsorb and remove the toxic heavy metal hexavalent chromium Cr(VI) in water. The EDTA-chitosan/Cu-BTC was prepared by the surface modification of Cu-BTC with EDTA-modified chitosan. The initial concentration effects of adsorbed
chromium solution, adsorbent dosage, adsorption time, adsorption temperature and pH of chromium solution on adsorption capacity were estimated using the single-factor optimisation experiment. Results show that the adsorption capacity of the modified composite was higher than that of Cu-BTC.
Cu-BTC and EDTA-chitosan/Cu-BTC exhibited significant adsorption of Cr(VI) under acidic conditions in water and basically independent of temperature. Their adsorption processes conformed with the pseudo-second-order model. The Langmuir adsorption isotherm model obtained the adsorption isotherm,
which indicated that the adsorption process was single molecule adsorption. Isotherm fitting obtained the maximum adsorption amounts of Cr(VI) for Cu-BTC and EDTA-chitosan/Cu-BTC at 27.32 and 46.51 mg·g-1, respectively. Factor and principal component analyses show that the
main factors affecting the adsorption of Cr(VI) in the EDTA-chitosan/Cu-BTC composites are pH, initial concentration and adsorption time. Therefore, EDTA-chitosan-modified Cu-BTC was a more feasible metal-organic framework material than Cu-BTC because of better adsorption performance, which
can be used for adsorption removal of Cr(VI) in water.
研究领域:
环境科学
·
材料科学
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DOI
PubMed
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2025
·
IF 5.4
Qianyu Wang,Changchang Ma,Dandan Liu,Shushan Song,Ziheng Song,Weijie Zhang,Huarui Han,Jiasheng Zhu,Kai Wei,Sheng Feng
Confining nano zero-valent iron (nZVI) into porous materials could prevent its aggregation and passivation. In this study, we confined nZVI into the cavity of zeolitic imidazolate framework-8 (ZIF-8) via sequential pre-adsorption ferric ion (Fe(III)) and NaBH 4 reduction processes. The optimized Cr(VI) removal rate of ZIF-8 confined nZVI (nZVI@ZIF-8) reached 1.2 × 10 −1 min −1 , 9.2- and 37.5-fold that of nZVI and ZIF-8, respectively. Interestingly, the removal rate constants of nZVI@ZIF-8 toward Cr(VI) still reached 9.6 × 10 −2 min −1 and 6.7 × 10 −2 min −1 with initial pH of 7.0 and 9.0, respectively, 13.0 (7.4 ×10 −4 min −1 ) and 23.9 times that of nZVI. More importantly, channels confinement significantly improved the reactive lifetime of nZVI for Cr(VI) removal. The electro-donating -NH 2 provided positive charge sites for CrO 4 2- or HCrO 4 - adsorption. Subsequently, the difference of Fermi level between nZVI and ZIF-8 drove electrons transfer from nZVI to ZIF-8 for surface Cr(VI) reduction. This study provides an avenue to enhance the performance of nZVI toward heavy metal ions removal by coupling surface adsorption and nano confinement.
研究领域:
环境科学
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材料科学
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产品关联
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2017
·
IF 3.387
Hong-Mei Cheng,Shi-Xi Zhao,Xia Wu,Jian-Wei Zhao,Lei Wei,Ce-Wen Nan
The crystal structure of the Li 2 MnSiO 4 cathode material would collapse during the charge and discharge process because of that the Mn-O coordination polyhedron changed from [MnO 4 ] into [MnO 6 ] in the process of Mn +2 to Mn +4 , but the Cr element could remain [CrO 4 ] crystal ligand from Cr +2 to Cr +4 , so Cr element substitution was used to improve the structural stability of the Li 2 MnSiO 4 cathode material. In this work, Li 2 Mn 1-x Cr x SiO 4 /C nanocomposites were synthesized by solid-state method. XRD, SEM and TEM observations show that the as-prepared Li 2 Mn 1-x Cr x SiO 4 /C materials presents an orthorhombic crystal structure (S.G. Pmn2 1 ), the particle size of Li 2 Mn 1-x Cr x SiO 4 /C powder ranges from 50 to 100 nm. The XRD and XPS results indicate that Cr +2 is successfully doped into Li 2 MnSiO 4 lattice and has well compatibility with Li 2 MnSiO 4 . The electrochemical results display that Li 2 Mn 92.5% Cr 7.5% SiO 4 /C exhibits significantly enhanced cycle stability and discharge capability. The initial discharge capacity of the Li 2 Mn 92.5% Cr 7.5% SiO 4 /C sample is 255 mAh g −1 , and the discharge capacity was still about 60 mAh g −1 after 50 cycles. Furthermore, the XRD patterns, TEM images and Raman analysis reveal that the Cr doping enhances the structural stability of Li 2 Mn 1-x Cr x SiO 4 /C and improves the electrochemical activity of the cathode. Thus, the Li 2 Mn 92.5% Cr 7.5% SiO 4 /C have shown potential applications for lithium ion batteries.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2019
·
IF 5.107
Yaoqiang Wang,Ziheng Cui,Gang Xiao,Yilin Zhao,Yu Jin,Zishuai Wang,Haijia Su,Tianwei Tan
To study the applicability and mechanism of the visible-light-driven photo-reduction of Cr(VI) is important since it will elucidate the chromium cycle in natural circumstances, and since this reduction reaction is important in treating wastewater contaminated by Cr(VI). Herein, we conducted an in-depth mechanism study for this process using formic acid as electron donor. The positive dependence of the Cr(VI) conversion on the incident light intensity and the good match between the apparent quantum yield (0.0039–0.39%) and the light absorption spectrum (550–365 nm) suggests a light-induced mechanism. The light-induced charge transfer occurs through the ligand-to-metal charge transfer state of the complex which forms between one dichromate molecule and two formic acid molecules through symmetrical or asymmetrical configuration as demonstrated by DFT simulation. EPR analysis further proves that this reaction occurs through a stepwise process with Cr(V) and Cr(IV) as the intermediates. The practical use of this photochemical procedure with broad electron donor scope and wide pH, reaction temperature, and initial Cr(VI) concentration ranges, is proven by the application potential evaluation. The efficient reduction of Cr(VI) by formic acid under sunlight further proves the applicability of this photochemical procedure for the treatment of Cr(VI) contaminated wastewater. Development of the present study into both the treatment of Cr(VI) contaminated wastewater, and other visible-light-driven photo-redox reactions between metals and organics are the subject of further research and results can be expected in the near future.
研究领域:
环境科学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2018
·
IF 6.735
Shixia Chen,Yifeng Huang,Xinxin Han,Zeliang Wu,Cen Lai,Jun Wang,Qiang Deng,Zheling Zeng,Shuguang Deng
Layered double hydroxides (LDHs) are currently attracting intense research interests as pollutant adsorbent due to its low cost, non-toxicity, structure amenability and anion exchange capability. Herein, 3-dimensional (3D) flower-like Ni/Al LDH were prepared to decorate H 3 PO 4 activated biomass-derived porous carbons (PAB) via a facile and green hydrothermal method. The as-synthesized nanocomposites (Ni/Al@PAB) displayed favorable removal performance towards both Cr(VI) and methyl orange (MO) from aqueous solution due to the inherited excellent Cr(VI) removal ability from PAB and MO removal ability from Ni/Al LDH. In single-component removal system, the maximum adsorption capacity of 271.5 and 412.8 mg/g for Cr(VI) and MO were achieved on Ni/Al@PAB, respectively. Remarkably, the removal capacity of Cr(VI) and MO both increased in the Cr(VI) MO binary system due to the synergistic effect including, (i) additional adsorption sites of N-containing groups from MO, (ii) electrostatic interactions by the reduced Cr(III), and (iii) mutual thermal compensation in the binary system. This work paved the way for designing novel LDHs-decorated porous carbon adsorbents and revealed that the acicular Ni/Al LDH decorated PAB could be applied as efficient and simultaneous adsorbent for coexisting toxic pollutants situations.
研究领域:
环境科学
·
材料科学
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产品关联
DOI
高影响因子
JOURNAL OF SEPARATION SCIENCE
·
2017
·Vol. 41
·期 3
·732-739
·
IF 2.557
Dan Feng,Yan Xia
A Cr-based metal–organic framework, namely, MIL-101(Cr), was modified with amino (NH 2 –) and urea (UR 2 –) groups, and the materials were evaluated as adsorbents for glyphosate, and a comparison with commercial activated carbon was also discussed. The effects of the adsorption factors, such as adsorbent concentration, adsorption time, pH and ionic strength were mainly investigated. The results showed that a pseudo-second-order rate equation described the adsorption kinetics mechanisms well, while the Langmuir model and the Freundlich model fitted different adsorption isotherms, respectively. Among the adsorbents we studied, NH 2 -MIL-101(Cr) showed the maximum adsorbing capacity, which is 64.25 mg/g when pH = 3.0, while UR 2 -MIL-101(Cr) did not reach the best adsorption performance due to the steric hindrance. The work opens up a new way for the modification of metal–organic frameworks for adsorption process.
研究领域:
环境科学
·
材料科学
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DOI
高影响因子
JOURNAL OF NANOPARTICLE RESEARCH
·
2017
·Vol. 19
·期 4
·1-13
·
IF 2.02
Zhang Lilan,Guo Yali,Iqbal Anam,Li Bo,Deng Min,Gong Deyan,Liu Weisheng,Qin Wenwu
Herein, six kinds of PdNPs (including icosahedron, sphere, spindle, cube, rod, and wire) were synthesized via simple methods. The catalytic activities were investigated by the reduction reaction of Cr(VI) and Suzuki coupling reaction. Chemically synthesized morphologies of the six catalysis were characterized by transmission electron microscopy, field emission scanning electron microscopy, and X-ray diffraction, etc. Pd icosahedron shows a better catalytic property than other PdNPs with a rate constants 0.42 min −1 for the reduction of Cr(VI). Moreover, the electrocatalyst shows that Pd icosahedron possesses a bigger surface area of 8.56 m 2 /g than other nanoparticles, which is attributed to the better catalyst. The Pd icosahedron possesses a better catalytic property, attributing to the abundant exposed {111} facets with high activity on Pd icosahedron. The catalytic activities are closely related to the surface area with the following order: icosahedrons ≥ sphere > rod > spindle > cube > wire. The Pd icosahedron catalyst represents a strong activity for Suzuki coupling reaction as well, outweighting is 80%. The results reveal that Pd icosahedron acts as an efficient catalyst compared to other PdNPs (wire, rod, sphere, spindle, and cube).
研究领域:
材料科学
·
催化化学
✓ 已验证
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2021
·
IF 4.539
Shuangxi Zhou,Ziming Zhou,Donghai Zhu,Huanhuan Jiang,Yue Qi,Shiyi Wang,Ye Jia,Wei Wang
To overcome problems associated with heavy metal pollution, lots of new functional materials have been used. As potential emerging environmental materials, covalent triazine frameworks (CTFs) have received extensive attention because of their high nitrogen content and the feature of pre-design to obtain the required molecular framework for specific applications. In this study, three CTFs were synthesized by terephthalonitrile (TPA) with the catalyzer of ZnCl 2 under different temperatures from 300 °C to 500 °C. Preparation temperature significantly affected the adsorption kinetics and capacity of CTFs. The CTF prepared under 500 °C (CTF500) showed the highest Cr(VI) adsorption capacity of 97.84 mg g −1 . The CTF500 was characterized with three different types of N, including pyrrolic N, pyridinic N, and quaternary N, thus providing support for the efficient adsorption of Cr(VI) from water. The mechanism of Cr(VI) removal was verified by a strong ion exchange interaction driving with the structure of quaternary N on CTF500. In addition, CTF500 also showed a stable Cr(VI) removal rate under a high ionic strength surrounding. In this study, CTFs with pre-designed functional groups could efficiently remove Cr(VI) by controlling their synthesis progress and showed great potential in future environmental applications.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
ACS Catalysis
·
2023
·
IF 12.9
Zhao Sun,Shufan Yu,Sam Toan,Rufat Abiev,Maohong Fan,Zhiqiang Sun
Steam reforming of methanol is a promising approach to achieving hydrogen storage, transportation, and in situ supply. However, this technology is restricted by its high CO selectivity and catalyst deactivation. In this study, CuCr2O4-based catalytic oxygen carriers are tailored for lattice oxygen participating in low-temperature methanol reforming. We found that the low-temperature activation of methanol originated from Cu–O–Cr structure intensification and highly activated lattice oxygen induction. Specifically, methanol can be activated at temperatures as low as 160 °C, on the one hand, attributed to the reinforcement of the Cu–O–Cr structure and, on the other hand, owing to the highly reactive lattice oxygen from the CuO4 tetrahedron in the CuCr2O4 spinel. Combined with XAS and Raman results, the formation of the Cu–O–Cr structure is demonstrated. The hydrogen production rate with an applied CuCr2O4-based catalytic oxygen carrier is 53.2% higher than the control group without Cu–O–Cr formulation. Satisfactory cyclic stability is retained after the 50th lattice oxygen induction and supplement cycle, ascribing to the Cu–O–Cr structure that strongly intensifies Cu–Cr2O3 interactions. DFT results reveal that the process of CH3OH → CH3O* is the rate-determining step. Compared to Cu(111) and Cr2O3(110), the tailored Cu(111)/Cr2O3(110) surface with a Cu–O–Cr structure exhibits the lowest potential barrier during this process, promoting low-temperature methanol reforming.
研究领域:
催化化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
Inorganic Chemistry Frontiers
·
2019
·Vol. 6
·期 11
·3057-3062
·
IF 5.934
Weixuan Zeng,Sheng Cao,Lulu Qiao,Anquan Zhu,Quanyin Ma,Xiewen Xu,Yi Chen,Jun Pan
In the present study, we report a one-step hydrothermal synthesis of visible-light response Cr-doped Sr2Ta2O7 nanosheets for photocatalytic hydrogen generation. It is discovered that the Cr ion is successfully doped into the Sr2Ta2O7 nanosheet crystal lattice and uniformly distributed without changing the crystal structure and morphology of the Sr2Ta2O7 host. Compared to pristine Sr2Ta2O7, the as-prepared Cr-doped Sr2Ta2O7 photocatalysts show enhanced photocatalytic activity for hydrogen generation under visible-light irradiation. The spectroscopy and Mott–Schottky results reveal that proper Cr doping can narrow the band gap of Sr2Ta2O7 as well as facilitate the separation of photo-generated electrons and holes, thus enhancing the photocatalytic performance under visible-light irradiation. This work provides a simple approach to fabricate visible-light active tantalum-based oxide photocatalysts.
研究领域:
材料科学
·
能源科学
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING SCIENCE
·
2014
·
IF 2.613
Shengnan Yu,Fusheng Pan,Sen Yang,He Ding,Zhongyi Jiang,Baoyi Wang,Zhuoxin Li,Xingzhong Cao
Hybrid membranes were fabricated with active layers composed of polydimethyl siloxane (PDMS) and metal organic framework MIL-101 (Cr), together with support layers composed of polyvinylidene fluoride (PVDF). Transmission electron microscopy (TEM), X-ray diffraction (XRD) and nitrogen adsorption were used to study the structure of MIL-101 (Cr) particles; scanning electron microscopy (SEM), infrared spectrum (IR), thermogravimetric analysis (TGA), thermomechanical analysis and positron anihilation lifetime spectroscopy (PALS) were employed to characterize the structural morphology, free volume property, thermal and mechanical features of the membranes. The effect of MIL-101 (Cr) incorporation on swelling and pervaporation performance of the hybrid membranes were evaluated with thiophene and n -octane mixture as model gasoline. The packing of PDMS chains was interrupted by MIL-101 (Cr), thus the fractional free volume was increased. Accordingly, the separation performance including permeation flux and selectivity was increased remarkably. The optimal performance was achieved when the weight fraction of MIL-101 to PDMS was 6% with a flux of 5.2 kg·m −2 h −1 (increased by 136% compared with the PDMS control membrane) and an enrichment factor of 5.6 (increased by 38% compared with the PDMS control membrane).
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）