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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DOI
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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DOI
RSC Advances
·
2018
·Vol. 8
·期 58
·33217-33227
·
IF 2.936
Wenjie Tang,Yue Wu,Tingting Gao,Yingqin Wei,Guowei Zhou
In the present work, leucoemeraldine-based hybrid porous polyanilines (LHPPs) have been synthesized by the Friedel–Crafts reaction of leucoemeraldine and octavinylsilsesquioxane (OVS) for Cr(VI) removal. The resulting LHPPs were characterized by Fourier transform infrared spectroscopy, powder X-ray diffraction, thermogravimetric analysis, scanning electron microscopy and N2 adsorption–desorption. The findings indiated that the LHPPs were amorphous, with apparent surface areas (SBET) in the range of 147 to 388 m2 g−1 and total volumes in the range of 0.13 to 0.44 cm3 g−1. Cr(VI) removal experiments displayed that the LHPPs exhibited highly efficient Cr(VI) removal performance. The maximum Cr(VI) removal capacity of LHPP-1 was 990.1 mg g−1 at 308 K and pH 1, which is higher than those of other reported polyaniline-based adsorbents. The adsorption process was a spontaneous, endothermic and chemical adsorption process. The adsorption behavior agreed well with Langmuir models and pseudo second-order equations. X-ray photoelectron spectroscopy and Fourier transformed infrared (FTIR) spectroscopy analysis revealed that the highly efficient Cr(VI) removal performance can be mainly attributed to the existence of numerous amine and imine groups on the surface of the LHPPs; these can function as adsorption active sites for Cr(VI) removal through electrostatic adsorption and reduction to Cr(III) under acidic conditions. Moreover, the LHPPs exhibited excellent adsorption selectivity for Cr(VI) despite the presence of other metal ions (K+, Cu2+, Mn2+) and anions (NO3−, SO42−). Therefore, the LHPPs have potential applications for Cr(VI) removal in industrial wastewater.
研究领域:
环境科学
·
材料科学
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DOI
高影响因子
Desalination and Water Treatment
·
2024
·
IF 1
Jie Li,Jiangtao He,Jianhong Huang,Qun Zhao,Yingjie Li,Senlin Tian
In this study, a novel set of polyamidoamine (PAMAM) dendrimer-modified biochar adsorbents (BC-G1, BC-G2, and BC-G3) were fabricated using the “graft onto” method. The results showed that the modified biochar adsorbents, with the inclusion of amine functional groups, exhibited higher Cr (VI) removal efficiency compared with the original biochar at pH 2. The adsorption capacity of biochar adsorbents was in the following order: BC-G2 > BC-G1 > BC-G3, with maximum adsorption capacity of 120.77, 101.52, and 40.98 mg/g at 30°C, respectively. The effects of cations Cu (II), Cd (II), Mn (II), Ca (II), and K (I) or anions (Cl – , NO 3 – , and HPO 4 2– ) in wastewater on the adsorption of Cr (VI) were insignificant, except for SO 4 2– . The adsorption process of all biochar materials for removing Cr (VI) was well described using the pseudo-second-order kinetics model and Langmuir adsorption isotherm model. The Cr (VI) adsorption was primarily based on the chemical adsorption of a single molecular layer, accompanied by electrostatic interaction, reduction, and surface complexation. In addition, the adsorbents could be regenerated using a 0.2 M NaOH solution, and the adsorption capacity of the BC-G2 remains high for four adsorption–desorption cycles. Therefore, PAMAM dendrimer-based biochar adsorbent (BC-G2) can effectively remove Cr (VI) from wastewater.
研究领域:
环境科学
·
材料科学
·
水处理
·
吸附技术
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DOI
高影响因子
INTERNATIONAL JOURNAL OF ENERGY RESEARCH
·
2021
·Vol. 45
·期 11
·16538-16550
·
IF 5.164
Sanchao Liu,Huihui He,Dongyun Zhang,Chengkang Chang
Summary To improve the electrochemical performances of high voltage LiCoMnO 4 spinel cathode material at 5.3 V, Cr doped LiCoMn 1-x Cr x O 4 ( x = 0, 0.025, 0.050, 0.075) materials were synthesized by a one-step solid-state at 750°C. Rietveld refinement results showed that the phase purity of spinel is promoted with the increase in Cr concentration, which can be explained by the strong Cr O bond that reduces oxygen deficiency and eliminates Li 2 MnO 3 impurity phase during the synthesis process. Such change in phase purity further causes the improvement in specific capacity, and the 5.0%Cr doped sample displays the best result with a value of 123.0 mAh/g at 0.1°C and 93.3 mAh/g at 10°C. For a comparison, the pristine sample only releases a capacity of 112.6 mAh/g at 0.1°C and 54.8 mAh/g at 10°C. Improved capacity retention, from 83.1% to 90.1% after 100 cycles at 1°C, is also observed due to the suppressed volume change during the redox process after the incorporation of Cr cations in the lattice. Promoted rate performance, attributed from the improved Li ion diffusion coefficient, is also confirmed in the experiment. The improvement of those electrochemical properties could be explained by high-phase purity and superior structural stability benefited from Cr-doping. Novelty statement LiCoMn 1-x Cr x O 4 ( x = 0, 0.025, 0.050, 0.075) materials were synthesized by a one-step solid-state at 750°C, Chromium had been confirmed to reduce oxygen loss during LiCoMnO 4 synthesis due to high oxygen affinity of Cr, which improves phase purity. As a result, the specific capacity was increased. Cr-doping enhances the structural stability so that capacity retention was promoted due to higher bond energy of Cr O than Mn O; rate performance was also enhanced due to the improved diffusion coefficient.
研究领域:
材料科学
·
电化学
·
储能
·
固态化学
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DOI
高影响因子
TRIBOLOGY INTERNATIONAL
·
2026
·
IF 7.6
Jiqi Xing,Xinze Zhu,Yupu Cao,Elissaios Stavrou,Juan Liu,Cheng Zhu
Molybdenum disulfide (MoS 2 ), a graphite-like layered two-dimensional material with excellent inherent lubricating properties, is commonly employed in dry vacuum environments. However, its lubrication performance deteriorates significantly under non-vacuum and humid conditions, limiting its broader practical applications. Cr doping has been shown to enhance the intrinsic anti-wetting properties of MoS 2 , enabling it to maintain favorable lubrication performance even in humid environments. Nevertheless, existing explanations for the anti-wetting mechanism of Cr-doped MoS 2 remain inconsistent with computational findings, and a clear molecular-level understanding is still lacking. This study supplementary developed high-precision all-atom force field parameters for the Cr-doped MoS 2 , with deviations of less than 1% from experimental test results and DFT-derived reference values, ensuring high reliability of subsequent simulations. The research found that neither single substitutional nor interstitial doping can match the crystallographic characteristics of materials prepared by the hydrothermal method, thus a mixed doping mode was proposed. Results suggest that when the ratio of substitutional to interstitial chromium atoms is 1:3, the simulated crystal characteristics achieve optimal consistency with experimental results; under this mode, the significant increase in shear modulus leads to a decrease in lubrication performance, which is consistent with experimental results. This manuscript investigates the intrinsic causes of friction performance variations in MoS 2 -based lubricating materials at the molecular level. It develops an empirical model correlating simulated mechanical properties and experimental average coefficient of friction (COF), laying a solid theoretical foundation for the subsequent molecular-level design of lubricants.
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DOI
高影响因子
ChemistrySelect
·
2026
·Vol. 11
·期 29
·e73937
·
IF 2.3
Yingjian Liao,Wenqi Xu,Liang Zeng,Songyun Deng,Xiaomao Hu,Song Lei,Linping Chen,Li li Geng,Shu Chen
Hexavalent chromium (Cr(VI)) is a highly toxic heavy metal contaminant commonly used in industrial applications, posing significant risks to human health and environmental sustainability due to its persistence and difficulty in degradation. Transition metal carbide (MXene) is an emerging two-dimensional material that has gained considerable attention for its potential in water pollutant removal. However, poor MXene stability and limited functional groups restrict its specific adsorption of target metal ions such as Cr(VI). Herein, a novel functionalized three-dimensional MXene composite gel (M/D/P) was synthesized via a photo-induced thiol-ene click reaction using MXene as the framework material. The multithiol-functionalized framework introduces abundant thiol groups, which facilitate the reduction of Cr(VI) to less toxic Cr(III) and enable chelation of Cr(III) with the adsorbent, driven by proton depletion during reduction. The adsorption behavior follows pseudo-second-order kinetics and the Langmuir model, indicating a chemical adsorption process. The maximum removal capacity reaches 347.71 mg·g − 1 , and the gel maintains 80% of its initial adsorption capacity after five cycles. The synergistic adsorption-reduction mechanism, involving electrostatic attraction, reduction, covalent bonding, and chelation, highlights M/D/P as a promising MXene-based adsorbent for water treatment applications. Graphical A multithiol-functionalized MXene composite gel (M/D/P) is synthesized via photo-induced thiol-ene click reaction. The abundant thiol groups enable synergistic adsorption–reduction of Cr(VI) through electrostatic attraction, chemical reduction, and chelation. The material achieves 374.71 mg·g − 1 removal capacity with excellent reusability.
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产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2026
·
IF 9.2
Yachao Huang,Hailong Zhong,Qihong Zhou,Wenqi Feng,Huan Li,Jinming Zeng,Chao Liu,Xiaopeng Qi
Developing a bifunctional catalyst that combines low cost and high performance for water electrolysis remains an unsolved challenge. In this study, a Cr-doped transition metal-based electrocatalytic material is synthesized on a stainless steel mesh substrate. The obtained Cr 0.2 -CoP/SS catalyst exhibits an overpotential of only 98 mV for the hydrogen evolution reaction (HER) at 10 mA cm −2 in alkaline electrolyte, and exhibits an overpotential of 254 mV for the oxygen evolution reaction (OER); in acidic electrolyte, the HER overpotential at 10 mA cm −2 is as low as 118 mV, and it demonstrates excellent stability. Furthermore, when Cr 0.2 -CoP/SS is used in traditional overall water splitting systems, the required voltage at 10 mA cm −2 is as low as 1.56 V. Theoretical studies show that Cr doping reduces the Gibbs free energy of hydrogen adsorption and narrows the bandgap to zero, which enhances catalytic activity and structural stability.
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产品关联
DOI
高影响因子
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
·
2025
·
IF 4.6
Jianlong Gu,Yuchen Liu,Jieyun Cai,Jie Long,Jing Ma,Zilong Zhang,Bing Yang,Hongming Meng,Yaling Yang,Li Gao
In this study, a colorimetric detection system for Cr(III) was established by leveraging the laccase-mimicking activity of two-dimensional Cu-based metal-organic frameworks (Cu-MOFs) modified with polydopamine (PDA) nanomaterials (Cu-MOF@PDA), through which Cr(III) specifically inhibits the catalytic performance. The Cu-MOF@PDA composite exhibited significant laccase-mimicking activity, enabling the oxidation of 2,4-dichlorophenol (2,4-DP) and 4-aminoantipyrine (4-AP), leading to the generation of a red-colored compound. Notably, the laccase-like activity of Cu-MOF@PDA was substantially enhanced under ultrasonic (US) stimulation. Free-radical trapping experiments revealed that the levels of singlet oxygen ( 1 O 2 ) and hydroxyl radicals ( OH) were markedly increased, while the electron transfer rate was accelerated, thereby boosting catalytic efficiency under US exposure. The research confirmed that Cr(III) binds to Cu-MOF@PDA, leading to the suppression of its catalytic activity. A strong linear correlation (R 2 = 0.995) was observed between the absorbance at 505 nm and Cr(III) concentrations ranging from 0.67 to 54.17 μg/L, with a low detection limit (LOD) of 0.26 μg/L (S/N = 3). The developed approach was effectively utilized for the analysis of Cr(III) and total Cr in cigarette tipping paper samples, yielding highly satisfactory results.
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产品关联
DOI
PubMed
高影响因子
ACS Sensors
·
2018
·
IF 5.711
Jieyao Song,Hongjian Zhou,Rui Gao,Yong Zhang,Haimin Zhang,Yunxia Zhang,Guozhong Wang,Po Keung Wong,Huijun Zhao
Selective determination of aquatic chromium is critically important because of the dramatic differences in health and environment impacts by trivalent and hexavalent forms of chromium; however, it is challenging. In this work, for the first time, a nonconjugated polymer fluorophore (GCPF) was synthesized by cross-linking chitosan with glutaraldehyde via Schiff base reactions and systematically investigated for selective determination of Cr(VI). The results revealed that the synthesized GCPF exhibited excellent photostability and water solubility. More importantly, GCPF possessed dramatically enhanced fluorescence intensity originated from the n−π* transitions of the Schiff base subfluorophore groups (e.g., C═N) that can be selectively and sensitively quenched by Cr(VI) through oxidative damages to C═N group. An effective EDTA masking agent approach was employed to minimize ionic interferences. In the presence of high concentration of interference ions including Cr(III), the quenching GCPF fluorescence is capable of selectively determining Cr(VI) within a concentration range up to 50 μM and a detection limit of 0.22 μM. The analytical performance of GCPF was also confirmed by analyzing real surface water and industrial samples.
研究领域:
环境科学
·
分析化学
·
材料科学
✓ 已验证
DOI
高影响因子
Polymers
·
2021
·Vol. 13
·期 7
·1035
·
IF 4.329
Chengbing Yuan,Yan Zhang,Jinshui Yao,Qinze Liu,Fan-Gong Kong
Herein, a synthetic strategy for a rough microsphere Cr(VI)-adsorbent via the reaction of tannic acid (TA) and 1,6-hexanediamine (HA) and using polyethylene glycol (PEG) as surface modifier was presented. This adsorbent was characterized by a Fourier Transform Infrared spectrometer (FTIR), thermogravimetic analysis (TGA), X-ray photoelectron spectroscopy (XPS), etc. Certain factors, including contact time, PEG@poly(tannin-1,6-hexanediamine) (PEG@PTHA) dosage, initial concentration, and experimental temperature affecting the Cr(VI) adsorption performance of adsorbent were explored. PEG@PTHA can adsorb Cr and the Cr(VI) was reduced up to Cr(III) due to the existence of phenolic hydroxyl groups. Its adsorption capacity can reach up to 300 mg/g within 10 min and approximately 100% removal percentage below the initial concentration of 100 mg/L. Its behavior matched well with the Langmuir isotherm model and pseudo-second-order kinetic model. A PEG@PTHA adsorbent with maximum adsorption capacity (450 mg/g) has great prospects in Cr(VI)-sewage treatment.
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DOI
高影响因子
COLLOID AND POLYMER SCIENCE
·
2026
·
IF 2.9
Chen Sihao,Cao Wei,Li Hao,Han Meng,Shi Wenhai,Liao Xiaobin,Zhou Zhenming
The interaction between new pollutants microplastics(MPs) and toxic heavy metals in a coexisting environment could alter both their environmental behavior and effects. Polyamide (PA) MPs show affinity toward highly toxic Cr(VI), thus the interaction mechanism needs to be further understood. Herein, PA MPs aged with different methods such as ultraviolet irradiation in air/sea water and chemical chlorination, were used to explore their adsorption and reduction performance and mechanism toward Cr(VI) under different solution conditions. The research results show that after aging treatment, the content of amide bonds in PA MPs decreased, while the number of oxygen containing functional groups increased. Under the condition of pH 3.0, the adsorption capacity reaches its maximum value. Higher temperatures facilitate the adsorption process, whereas the presence of salinity and dissolved organic matter (DOM) considerably hampers adsorption. The behavior of PA MPs in adsorption aligns with the pseudo-second-order kinetic model as well as the Langmuir adsorption isotherm model. Further studies show that the binding of Cr(VI) to PA MPs is primarily achieved through electrostatic interactions, complexation, and hydrogen bonding. It is important to mention that PA MPs have the ability to convert Cr(VI) to Cr(III) in solution, even in conditions involving UV light, the presence of DOM, and environments lacking oxygen. UV aging enhanced the adsorption and reduction performance of PA MPs for Cr(VI). This research offers fresh scientific insights into the mechanisms of formation and the environmental interactions related to pollution caused by microplastic-heavy metal composites. Graphical abstract
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产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）