Environmental Science-Nano
·
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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高影响因子
INORGANIC CHEMISTRY COMMUNICATIONS
·
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 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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高影响因子
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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PubMed
高影响因子
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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高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2015
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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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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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PubMed
高影响因子
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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高影响因子
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
·
环境科学
·
表面化学
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高影响因子
ChemCatChem
·
2025
·
IF 3.9
Sun Liangliang,Gong Qiqi,Chen Zihao,Li Kangyi,Jia Yifei,Deng Xingbiao,Feng Yuyang,Shi Yunmei,Liu Jie,Liu Zezheng,Xue Lirong,Yan Jipeng
This work presents a rapid synthesis method for self-supported catalytic electrodes using laser as the sole heat source. We fabricated Cr-doped RuO 2 supported on titanium plate via laser direct writing as an oxygen evolution reaction (OER) anode for water splitting, and identified the optimal catalytic electrode by systematically investigating chromium doping ratios and laser ablation cycles. The results demonstrate that the catalytic electrode prepared with five repeated laser scanning cycles (300 W mm −2 power density, 100 mm min −1 scanning speed) exhibits superior performance. Among all samples, the 0.7Cr–Ru/Ti-5 electrode with a Cr/Ru atomic ratio of 7:10 shows the highest electrocatalytic activity, achieving a low overpotential of 174 mV@10 mA·cm −2 in 0.5 M H 2 SO 4 solution. Remarkably, it maintains stable operation for 70 h without noticeable potential degradation, indicating exceptional catalytic durability. This study establishes a novel laser-energy-driven strategy for synthesizing high-performance water electrolysis anodes with tunable characteristics. Graphical A novel (Cr 2 O 3 -RuO 2 -Ru)/Ti oxygen evolution electrode was rapidly fabricated using an innovative fibre laser ablation technique, differing from conventional methods. The catalyst was synthesized by subjecting precursor-coated titanium substrates to multiple laser ablations in an N 2 atmosphere. The high-temperature conditions generated reductive species locally, partially reducing ruthenium compounds to metallic Ru. Kinetic constraints and limited solid-phase diffusion hindered complete reduction of ruthenium species. Meanwhile, polyvinylpyrrolidone (PVP), rich in oxygen functional groups, reacted with residual ruthenium compounds to form RuO 2 . Under laser irradiation, chromium ions reacted with PVP's oxygen functional groups, leading to Cr 2 O 3 formation. Consequently, Cr 2 O 3 /RuO 2 /Ru active units were created on the titanium substrate.
研究领域:
材料科学
·
电化学
·
能量转换
·
纳米制造
·
催化
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高影响因子
CHEMICAL GEOLOGY
·
2022
·
IF 4.685
Liyan Deng,Fu Liu,Zecong Ding,Yuzhen Liang,Zhenqing Shi
Fe(II)-bearing clay minerals are abundant in soils and are critical to control the fate of the highly toxic hexavalent chromium (Cr(VI)). Even though the reduction of Cr(VI) by Fe(II)-bearing clay minerals has been extensively studied, the effect of the commonly co-existing natural organic matter (NOM) on this process is poorly understood. This study aimed to understand the kinetics of Cr(VI) reduction by a typical Fe(II)-bearing clay mineral (i.e., reduced nontronite (rNAu-2)) in the presence of Suwannee River NOM and to unveil the possible mechanisms. Cr(VI) reduction experiments were conducted with different NOM concentrations in a range of 0 to 100 mg C L −1 under circumneutral pH. The time-course aqueous-phase measurements and solid-phase characterizations were performed with a combination of wet chemical methods, transmission electron microscopy (TEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) analyses. The results demonstrated that NOM inhibited Cr(VI) reduction overall, mainly due to the decrease of Cr(VI) sorption on rNAu-2 by mineral-bound NOM. Besides the predominant solid Cr(III) species, soluble and mobile Cr(III) complexes were formed during reduction. Interestingly, the reduction rate ( k ) decreased with the increase of NOM concentration from 0 to 20 mg C L −1 , but kept increasing when the concentration of NOM increased from 30 to 100 mg C L −1 . The contrary pattern is due to the increasing promotion effects that offset the inhibitory effect caused by competitive sorption between Cr(VI) and NOM. The promotion effects may include weakening the mineral passivation by forming stable aqueous NOM-Cr(III) complexes, accelerating the electron transfer rate by dissolving rNAu-2, and donating electrons through NOM-Fe(II/III) complexes and/or NOM-Cr(V) complexes. This study extends our knowledge of Cr(VI) reduction by clay minerals in organic matter-rich soils and sediments and has important implication for understanding the transport and long-term behavior of Cr in the environment.
研究领域:
环境科学
·
土壤学
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高影响因子
Sensor Letters
·
2017
·Vol. 15
·期 8
·682-689
·
IF 0
Li Yueqi,Hu Jingfang,Zou Xiaoping,GuoweiGao
In this paper, a simple and highly sensitive sensing interface of graphene film for hexavalent chromium (Cr(VI)) determination has been prepared by controllable electrochemical deposition on the gold electrode surface. The graphene film was obtained by direct electroreduction of graphene
oxide (GO) in suspension solution. The investigations on deposition parameters of this controllable preparation, such as potential and deposition time, were carried out by the potentiostatic method to study the effects of them on the graphene film. The fabrication process and electrochemical
properties of graphene film were characterized by scanning electron microscope (SEM), transmission electron microscope (TEM) and electrochemical techniques, respectively. The conditional parameters, including detection potential, the concentration of supporting electrolyte and pH, were optimized
for Cr(VI) analysis. Without preconcentration, chronoamperometry method was used for Cr(VI) fast detection. Under the optimized conditions, the graphene film modified electrode provided a fast detection process, a wide linear range from 5 μg/L to 2000 μg/L, and a low detection
limit of 0.5 μg/L (S/N ≥ 3). Also, the developed graphene film showed a good stability and anti-interference for Cr(VI) determination. The reported work holds promise for practical application due to its simple, fast, environment-friendly and economical natures.
研究领域:
环境科学
·
分析化学
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