Environmental Science-Nano
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2024
·
IF 5.8
Chaorong Chen,Haiyang Xian,Jing Liu,Qingze Chen,Xiaoliang Liang,Runliang Zhu,Michael F. Hochella
Photochemical and adsorptive reactions occurring at the mineral–water interface are of great importance in controlling the fate and transport of contaminants in nature, but the effects of the mineral surface structure on the interplay of these two processes and the underlying mechanisms remain largely unknown. In this work, two different structurally well-defined hematite nanocrystals were employed to explore the coupled photoreduction and immobilization of Cr(VI) on various facets of hematite under light irradiation. Compared with hematite quasi-nanocubes (HNCs) exposing only {012} facets, hematite nanoplates (HNPs) with exposed {001} and {113} facets exhibited higher immobilization ability for Cr(VI) under light irradiation, indicating that the coupled process of photoreduction and adsorption of Cr(VI) strongly relied on the particularly exposed facets of hematite. X-ray photoelectron spectroscopy measurements indicated that the removed Cr(VI) from solution was mainly immobilized on hematite surfaces in the form of Cr(III) (the reduced products of Cr(VI)). Transmission electron microscopy and electron energy-loss spectroscopy results revealed that the accumulation of Cr species was predominantly on the {113} facets of HNPs and the {012} facets of HNCs. Theoretical calculations show that the work function difference between the {113} and {001} facets was directly linked with the effective separation of photogenerated electron–hole pairs in HNPs, which is beneficial for the reduction of Cr(VI). The results of desorption experiments indicate that the coupling of photoreduction and adsorption processes significantly promotes the long-term immobilization of Cr species and effectively reduces their environmental risks (the desorption of Cr(VI) from the HNP and HNC samples decreased from 35.9% and 33.5% to 0.3% and 1.7%, respectively). Overall, the exposed facets can significantly affect the electron transfer properties of hematite as well as the binding affinity for Cr species, thereby governing the reduction and immobilization behavior of Cr(VI) on various facets of hematite. These results advance our understanding of the speciation and immobilization of redox-sensitive contaminants at the surfaces of semiconducting minerals in nature.
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Environmental Science-Nano
·
2024
·
IF 5.8
Shengnan Zhang,Lingyi Li,Junxue Li,Wei Cheng
Hematite displays diverse crystal structures and often coexists with Fe(II), both of which are crucial in controlling the fate and mobility of Cr(VI). However, the mechanisms underlying Cr(VI) removal in the presence of Fe(II) on various hematite facets remain elusive. This study aims to elucidate the facet-dependent reactivity of hematite nanocrystals in conjunction with Fe(II) for the removal of Cr(VI) from aqueous solutions. Hematite nanoplates (HNPs), predominantly composed of {001} facets, and nanorods (HNRs), exposing both {001} and {110} facets, were synthesized and characterized. Their Cr(VI) removal capabilities were evaluated in hematite–Cr(VI) and hematite–Fe(II)–Cr(VI) systems, as well as the Fe(II)–Cr(VI) system. The adsorption of Fe(II) and Cr(VI) on hematite surfaces was highly dependent on the crystal facets and pH, with HNRs demonstrating superior Cr(VI) adsorption over HNPs, especially under acidic conditions. Neutral pH favored Fe(II)–Cr(VI) redox reactions and Fe(II) adsorption. The hematite–Fe(II) couple displayed a synergistic effect in removing Cr(VI) under acidic conditions, which was not observed under neutral conditions. The presence of Fe(II) notably enhanced Cr(VI) adsorption onto hematite, and bound Fe(II) facilitated electron transfer, accelerating Cr(VI) reduction. HNRs–Fe(II) exhibited higher Cr(VI) removal efficiency than HNPs–Fe(II) due to their lower free corrosion potential and improved electron transport properties. This research underscores the potential of facet engineering in optimizing hematite nanocrystals for environmental remediation, specifically in Cr(VI)-contaminated environments.
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Journal of Environmental Chemical Engineering
·
2024
·
IF 7.4
Jianle Wang,Huiqun Zhang,Xiaoyao Wang,Xueming Liu,Hong Deng
Soil washing is employed to prevent the issue of Cr re-oxidation following the remediation of Cr-contaminated soil by transferring contaminants from the soil to the wash solution through the dissolving action. Nevertheless, rapidly screening effective washing agents remains challenging. This study conducted batch experiments to gather dataset on key factors (soil properties, Cr sequential extraction and type of washing agent) and Cr content after washing with 250 experimental data points. We developed 12 machine learning models, among which the light gradient boosting machine model excelled in predicting Cr content after washing, determining soil suitability for washing. Furthermore, the adaptive boosting and random forest models preferably predicted Cr content after various washing agents treatments, facilitating optimal detergent identification. Based on the feature analysis, soil pH, exchangeable potassium , reactive iron oxides , and Cr sequential extraction can account for most of the differences in washing treatment. To further validate our model, we used an additional 60 experimental data points, including soil properties with pH values beyond the range of the initial 250 data points. The R 2 value of the predicted fit to the actual results was 0.801. This study provides the feasibility of improving the efficiency of technical remediation of Cr-contaminated soils.
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WATER AIR AND SOIL POLLUTION
·
2017
·Vol. 228
·期 11
·1-10
·
IF 1.702
Laipan Minwang,Fu Haoyang,Zhu Runliang,Rivera Linda,Zhu Gangqiang,Zhu Jianxi,He Hongping
Hexavalent chromium (Cr(VI)) and dyes are of particular environmental concern and need to be removed from water urgently due to their high toxicity. Herein, we explored the possibility of electron transferring from dye Orange II (OII) to Cr(VI) under UV and simulated solar light irradiation, expecting to simultaneously decolorize dyes and reduce Cr(VI). Experimental results show that light irradiation can partially decolorize OII but has no ability to reduce Cr(VI) in solution only with OII or Cr(VI). However, both dyes and Cr(VI) can effectively and simultaneously be decolorized and reduced in the solution containing both OII and Cr(VI) under light irradiation, and a low pH level and high OII/Cr(VI) concentration ratio significantly favor the co-removal. Additionally, insoluble organo–Cr(III) complexes identified by FTIR and XPS characterization were generated during the reaction. These complexes are beneficial to the removal of chromium and total organic carbon from water. The possible degradation pathway of OII is further proposed based on the detection of degraded products by GC-MS analysis. The results of this work offer an approach for simultaneously removing multiple contaminants.
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MOLECULES
·
2024
·Vol. 29
·期 18
·4477
·
IF 4.2
Fuhua Wei,Qin Zhang,Qinhui Ren,Hongliang Chen,Yutao Zhang,Zhao Liang
The Zn/Cr-MOFs/TiO2composites were synthesized using the solvothermal method. XRD, FTIR, and SEM techniques were utilized to characterize the Zn/Cr-MOFs/TiO2composites employed for simulating levofloxacin hydrochloride in wastewater. The impact of the mass of the Zn/Cr-MOFs/TiO2composite, concentration of levofloxacin hydrochloride, solution pH, and temperature on the adsorption performance was investigated. Experimental findings indicated that at pH 6, the maximum removal efficiency of levofloxacin hydrochloride by the Zn/Cr-MOFs/TiO2composite was achieved at 88.8%, with an adsorption capacity of 246.3 mg/g. To analyze the experimental data, both pseudo-first-order and pseudo-second-order kinetics models were applied, revealing that the pseudo-second-order model provided a better fit to the data. Additionally, Langmuir and Freundlich isotherm models were used to study equilibrium adsorption behavior and showed good agreement with both kinetic modeling and Langmuir isotherm analysis results. These observations suggest that monolayer adsorption predominates during the removal process of levofloxacin hydrochloride by Zn/Cr-MOFs/TiO2composites.
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高影响因子
INORGANIC CHEMISTRY COMMUNICATIONS
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2024
·
IF 4.4
Fuhua Wei,Fang Lan,Qinhui Ren,Hongliang Chen,Yutao Zhang,Zhao Liang
The Y/Cr-MOFs were synthesized via solvothermal treatment using 1, 3, 5-benzoic acid as the organic ligand and yttrium acetate hydrate and chromium acetate as the metal ions. The structures of the prepared Y/Cr-MOFs were characterized using FT-IR, XRD, TG, and SEM techniques. These characterized Y/Cr-MOFs were employed to investigate the adsorption efficiency of minocycline. Experimental findings indicate that minocycline adsorption by Y/Cr-MOFs follows both the second-order kinetic model and Freundlich isotherm. Within a span of 5 h, up to 90.4 % of minocycline can be adsorbed by Y/Cr-MOFs at pH 6. Moreover, a maximum removal capacity of minocycline reaching 506 mg/g was achieved with Y/Cr-MOFs. These results demonstrate the practical application potential of utilizing Y/Cr-MOFs for efficient minocycline adsorption.
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JOURNAL OF SOLID STATE CHEMISTRY
·
2025
·
IF 3.5
Mengyao Li,Ping Wu,Xiaoli Han,Shanshan Shi,Shiping Zhang,Li Wang,Min Xu,Xiulan Huai
Adsorption-based thermal energy conversion systems offer a sustainable solution for space heating and cooling applications. However, due to the limited performance of solid adsorbents, the large-scale application of this technology still requires further research. To address this challenge, we developed a composite adsorbent by integrating a graphene oxide (GO)-modified metal-organic framework (MIL-101(Cr)) with LiCl. The material was characterized using a variety of techniques to assess its improvement in three areas: water adsorption performance, heat propagation rate and stability. The synthesized material was systematically characterized to evaluate three key performance parameters: water adsorption capacity, thermal conductivity, and cyclic stability. The optimized composite LMG-3 (90 wt% LiCl) exhibits a tenfold increase in water absorption capacity compared to MIL-101(Cr)@GO at P/P 0 = 0.3. The introduction of GO significantly increases the heat diffusion coefficient, and the material exhibits excellent cyclic stability and inhibits salt deliquescence, demonstrating its potential for adsorptive thermal storage applications.
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CHEMICAL PHYSICS LETTERS
·
2022
·
IF 2.719
Tian Zhao,Wei Geng,Ming Dong,Yi Zhao,Christoph Janiak,Ling Shen,Jie Ying,Xiao-Yu Yang
MIL-101(Cr) can be tailored by using different modulators in the synthesis to obtain several morphological variants, including micro-sized MIL-101(Cr) (M-MIL), nano-sized MIL-101(Cr) (N-MIL) and nanofused hierarchical porous MIL-101(Cr) (H-MIL). Though those MILs had comparable porosity, H-MIL possessed remarkable higher adsorption capacity toward the anionic dye Congo red (CR, 1467 mg/g) and cationic dye methylene blue (MB, 301 mg/g) than the other two samples. Furthermore, in the cyanosilylation reaction, H-MIL also revealed significantly enhanced catalytic activity (yield ∼ 95.1%). Thus, the outstanding performance of H-MIL could be attributed to its hierarchically porous structure which accelerated the mass transfer rate and exposed more catalytic active sites.
研究领域:
材料科学
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环境科学
·
化学工程
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RSC Advances
·
2018
·Vol. 8
·期 10
·5433-5440
·
IF 2.936
Chol-Nam Ri,Song-Gol Kim,Kyong-Sik Ju,Hyok-Su Ryo,Chol-Ho Mun,U-Hyon Kim
A novel Bi2MoO6/Bi4V2O11 heterostructured photocatalyst was successfully fabricated using a facile one-pot solvothermal method. This heterojunction consists of homogeneous dispersed Bi4V2O11 nanocrystals anchored on the surface of Bi2MoO6 nanoflakes, endowing the heterojunction with nanosized interfacial contact. Based on the favorable interfacial contact, the band alignment at the heterojunction effectively facilitated photo-generated carrier transfer, which was verified by photoelectrochemical and photoluminescence measurements. Thereby, in contrast with pristine Bi2MoO6 and Bi4V2O11, the as-synthesized heterojunction with nanoscale contact exhibited significantly enhanced photocatalytic activity towards the degradation of MB and the reduction of Cr(VI). In addition, the as-fabricated Bi2MoO6/Bi4V2O11 heterojunction exhibited good cycling stability for MB degradation after 4 cycles. Finally, a plausible photocatalytic mechanism for MB degradation over the Bi2MoO6/Bi4V2O11 heterojunction was discussed in detail. This work not only reports a highly efficient photocatalyst but also sheds light on the design and optimization of a heterojunction.
研究领域:
材料科学
·
环境科学
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MACROMOLECULAR RAPID COMMUNICATIONS
·
2022
·Vol. 43
·期 20
·2200403
·
IF 5.006
Ting Qu,Qicheng Chang,Dekang You,Man Huang,Xianyan Gong,Jie Wang,Bojie Li,Genwen Zheng,Fuqiang Hu,Fei Zhong,Chunli Gong,Hai Liu
The morphology transition from primary to hierarchical adsorption-type microporous domains of amphiphilic block copolymer (BCP) honeycomb-structured films is demonstrated by a facile swollen based breath figure (BF) method. The characteristic parameters of poly(4-vinylpyridine)- block -polystyrene (P4VP- b -PS) hierarchical micro- and submicroporous films can be controlled by changing the length of segments or subsequent swelling conditions. A plausible mechanism is demonstrated in this research. A typical amphiphilic BCP with very low volume content of hydrophilic blocks ( f P4VP ≤ 0.050) can efficiently stabilize water droplets and inherently assist in the formation of morphology transition. This BCP film can be used for Cr(VI) removal from wastewater, which additionally has enormous potential application in the field of novel optical devices, soft lithography, size-selective separation, etc.
研究领域:
材料科学
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环境科学
·
表面化学
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APPLIED SURFACE SCIENCE
·
2024
·
IF 6.3
Zihan Yang,Jingkai Yang,Lixia Li,Wanning Cao,Jiao Zhang,Hongli Zhao,Liqin Wang
The challenge of creating effective S-scheme visible-light photocatalysts persists due to the inactive visible-light-driven component and the low band-gap characteristics of semiconductors. In this work, we developed a novel F-BiVO 4 /g-C 3 N 4 /CdS dual S-scheme photocatalyst using a sonochemical method. The removal efficiency of Cr(VI) and ciprofloxacin (CIP) can reach 98 % and 90 % in 5 min and 30 min, respectively, under simulated solar illumination. The excellent photocatalytic activity can be attributed to the efficient carrier separation and transport with the help of internal electric field at the interface. This work also reveals the reduction process of Cr(VI), as well as the intermediates and pathways involved in the CIP degradation, taking into account practical situations and expanding its potential applications. This research presents promising prospects for the design of bismuth-based dual S-scheme heterojunctions in the field of environmental remediation.
研究领域:
环境科学
·
材料科学
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INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2015
·
IF 2.587
Meng Chen,Jiaqi Yan,Ying Tan,Yongfei Li,Zhimin Wu,Langsheng Pan,Yuejin Liu
Hydroxyalkylation of phenol with formaldehyde to bisphenol F was investigated over the metal–organic frameworks of MIL-100(Fe or Cr) and MIL-101(Fe or Cr) encapsulated with Keggin phosphotungstic acid (PTA). PTA@MIL-100(Fe or Cr)(β) and PTA@MIL-101(Fe or Cr)(β) with different β values (the molar ratio of W/M, where M = Fe or Cr) were prepared and characterized by XRD, BET, FT-IR, TG, SEM, TEM, and ICP. The research results showed that PTA@MIL-100(Fe or Cr)(β) had a higher catalytic activity than PTA@MIL-101(Fe or Cr)(β). PTA@MIL-100(Fe)(0.4) was the most effective among the studied catalysts and had excellent reusability. A 92.12% product yield and 93.01% selectivity for bisphenol F could be obtained over the PTA@MIL-100(Fe)(0.40) catalyst. The effects of the reaction time, reaction temperature, catalyst concentration, and phenol/formaldehyde molar ratio on the reaction performance were also investigated. A plausible mechanism for hydroxyalkylation of phenol with formaldehyde to bisphenol F was proposed.
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