Molecular Catalysis
·
2023
·
IF 4.6
Yi Liu,Shuangjiang Li,Xiaojian Yu,Ying Chen,Xiaoning Tang,Tianding Hu,Lan Shi,Manoj Pudukudy,Shaoyun Shan,Yunfei Zhi
For the simultaneous attainment of the utilization of renewable biomass resources and the mitigation of greenhouse effects, it is very promising to develop a green, recyclable, and highly efficient heterogeneous catalyst for the synthesis of cyclic carbonates by CO 2 cycloaddition reaction with epoxides. Herein, novel cellulose nanofibers (CNF) supported (Salen)Cr(Ⅲ) complex was effectively synthesized for the aforementioned reaction. The cellulose nanofibers (CNF) were firstly modified with (3-aminopropyl) triethoxysilane (APTES), and then its Schiff base with salicylaldehyde was synthesized, which further subjected to coordination treatment with chromium chloride to form a novel heterogeneous catalyst, labelled as CNF-(Salen)Cr(Ⅲ). The catalytic performance of the catalysts shown that CNF-(Salen)Cr(Ⅲ) and co-catalyst TBAB can synergistically catalyze the cycloaddition of CO 2 with epichlorohydrin (ECH) at mild reaction conditions, and the yield of chloropropene carbonate (CPC) reached up to 97.8% with high selectivity. The CNF-(Salen)Cr(Ⅲ) complex maintained high catalytic activity after six cycles of repeated runs and has acceptable catalytic effect on other series of epoxies. Based on density functional theory (DFT) calculations, a reaction mechanism including adsorption activation of epoxides, epoxides ring opening, CO 2 insertion, and the formation of cyclic carbonate, was proposed for the CNF-(Salen)Cr(Ⅲ) complex catalyzed cycloaddition of CO 2 with epoxides.
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高影响因子
Journal of Environmental Chemical Engineering
·
2023
·
IF 7.7
Linshan Zhang,Guozong Yue,Luming Yang,Deshun Huang
Ultra-thin MXene nanosheets (Nss) were facilely prepared via delaminating and intercalating the multi-layered MXene using tetramethylammonium hydroxide (TMAOH). Electron-rich characteristics, abundant surface active sites and the negative charges made MXene Nss having both good reduction ability and adsorption capacities, which would effectively remove anion Cr(VI) via reduction and remove cation Cr(III) via adsorption. Batch adsorption tests were carried out to study the pH impact, adsorption kinetics and isotherms. Upon adsorption, the well dispersed MXene Nss suspension was aggregated to form flocs and sediment at the bottom. The maximum Cr(VI) and Cr(III) removing capacities are calculated to be 554.9 mg/g at 318 K and 283 mg/g at 298 K, respectively. The mechanisms on Cr(VI)/Cr(III) adsorption were well studied employing SEM, TEM , XPS and FT-IR. In addition, the MXene Nss also showed good adsorption capacity towards other metal cations (such as Cu 2+ , Cd 2+ , and Pb 2+ ), manifesting that the current MXene Nss has the potential to be used as a general-purpose adsorbent.
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FUEL PROCESSING TECHNOLOGY
·
2016
·
IF 3.847
Ting-Ting Zhao,Wen-Zhi Ge,Fen Yue,Ying-Xiong Wang,Christian Marcus Pedersen,Fan-Gui Zeng,Yan Qiao
Lignite showed high capacity for reducing Cr(VI) to Cr(III) and hence removed Cr(VI) from aqueous solution, but the reduced Cr(III) cannot be released from adsorbent afterwards especially under acidic condition. In order to know why Cr(III) ions are immobilized within lignite adsorbent and how to recovery Cr species, the interaction of Cr(III) ions with lignite oxidized by Cr(VI) was studied by X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR). The data obtained from these studies indicate that Cr(III) ions are bonded to oxygenic functional groups in lignite oxidized by Cr(VI) and electrons are delocalized over -O-Cr-O- domain. It is also revealed that the O atoms of C = O and C-O groups in the adsorbent matrix are bonded to Cr(III) ions along with the decrease of electron density, while the O atoms of O -C = O group are along with the increase of electron density. Based on these important structural information, we developed a method to treat Cr-loaded lignite further and to recover the Cr species.
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高影响因子
CHINESE JOURNAL OF CHEMISTRY
·
2014
·Vol. 32
·期 5
·434-442
·
IF 1.04
Changhua Song,Hui Liu,Yuan Li,Shuai Ge,Hongwei Wang,Wenshuai Zhu,Yonghui Chang,Changri Han,Huaming Li
A series of metal-Al 2 O 3 catalysts were prepared simply by the conventional impregnation with Al 2 O 3 and metal chlorides, which were applied to the dehydration of fructose to 5-hydroxymethylfurfural (HMF). An agreeable HMF yield of 93.1% was achieved from fructose at mild conditions (100°C and 40 min) when employing Cr(III)-Al 2 O 3 as catalyst in 1-butyl-3-methylimidazolium chloride ([Bmim]Cl). The Cr(III)-Al 2 O 3 catalyst was characterized via XRD, DRS and Raman spectra and the results clarified the interaction between the Cr(III) and the alumina support. Meanwhile, the reaction solvents ([Bmim]Cl) collected after 1 st reaction run and 5 th reaction run were analyzed by ICP-OES and LC-ITMS and the results confirmed that no Cr(III) ion was dropped off from the alumina support during the fructose dehydration. Notably, Cr(III)-Al 2 O 3 catalyst had an excellent catalytic performance for glucose and sucrose and the HMF yields were reached to 73.7% and 84.1% at 120°C for 60 min, respectively. Furthermore, the system of Cr(III)-Al 2 O 3 and [Bmim]Cl exhibited a constant stability and activity at 100°C for 40 min and a favorable HMF yield was maintained after ten recycles.
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Environmental Technology & Innovation
·
2020
·
IF 3.356
Jiahong Wang,Saleem Atif,Dan Zhang
EGTA functionalized magnetic microsphere (Fe 3 O 4 @SiO 2 @EGTA) was prepared for the removal of Cr(III) from highly saline organic wastewater environment. The synthesized adsorbent was characterized with Fourier transform infrared (FTIR), powder x-ray diffraction (XRD), thermogravimetric analysis (TGA) and x-ray photoelectron spectrometry (XPS). The characterization techniques depicted the successful surface modification of magnetic particles (Fe 3 O 4 @SiO 2 ) with the functional groups of EGTA without changing its crystal structure. The maximum adsorption amount of Cr(III) was 25.25 mg ⋅ g −1 at pH 4.0. The Langmuir isotherm was well fitted on the adsorption data, while adsorption equilibrium was achieved in first 15 min, and the equilibrium data well explained by pseudo second order model. The smaller concentrations of inorganic cations (Na + , Ca 2＋ , Mg 2 + ), organic acids (EDTA, Citric acid , Formic acid) and complexing agent with high salt system reduce the adsorption capacity to some extent, but after that the higher concentrations of these competing species have no apparent effect on the adsorption performance. According to the XPS analysis, the carboxyl and amino groups were responsible for the adsorption of Cr(III), while the main mechanism of adsorption were coordination complex and electrostatic interaction. The prepared adsorbent can be readily isolated by external magnetic field and regenerated for several times and still possess higher adsorption performance.
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HYDROMETALLURGY
·
2019
·
IF 3.465
Guang-jin Zhu,Hai-yan Tang,Hong-ling Zhang,Li-li Pei,Peng Zhou,Yi-lang Shi,Zai-hua Cai,Hong-bin Xu,Yi Zhang
An ion-imprinted polymer (IIP) was synthesized by radical copolymerization for use in the removal of trace Fe(III) ions from Cr(III)-containing solutions. During the synthesis process, Fe(III) ions, acrylic acid and ethylene glycol dimethacrylate were employed as the template ions, functional monomer and cross-linker, respectively. The optimal mole ratio of acrylic acid to Fe(III) ions, which significantly affected the adsorption performance, was determined. The maximum static adsorption capacity of the polymer for Fe(III) ions was 114.25 mg g −1 , with a selective factor ( k ) of 492.18 and a relative selective factor ( k′ ) of 50.87 for Fe(III)/Cr(III). The Fe(III) ions removal efficiency could reach 94.43%, leading to a final Fe(III) concentration of 0.053 mg L −1 in the treated solution. After the removal process, the mass ratio of Cr(III) ions to Fe(III) ions was higher than 26, 000:1 in the solution, with an initial mass ratio of Cr(III) to Fe(III) ions of 1500:1.
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ANALYTICA CHIMICA ACTA
·
2020
·
IF 5.977
Xianfeng Wang,Chengxiang Chu,Jiayi Lv,Yuanyuan Jia,Libo Lin,Mei Yang,Suyi Zhang,Danqun Huo,Changjun Hou
High-performance analysis of heavy metal ions is great importance in both environment and food safety. In this work, a facile and reliable colorimetric sensor was presented for simultaneous detection of Cu 2+ and Cr 3+ based on indicator-displacement assay (IDA). As a typical silicate nanomaterials , ZnSiO 3 hollow nanosphere (ZSHS) exhibited an outstanding ion exchange capacity. Zincon was incorporated with the ZSHS to form a zincon/ZSHS hybrid ionophore with a blue color. Upon the addition of Cr 3+ , IDA reaction and selective ion exchange occurred with the color change of zincon/ZSHS ionophore from blue to yellow. With such a design, colorimetric measurement of Cr 3+ was realized. The linear concentration for Cr 3+ detection ranged from 0.5 μM to 75 μM with the LOD of 83.2 nM. Furthermore, we also screened different kinds of complexing agents that may respond with zincon/ZSHS ionophore and various metal ions. It was found that tartaric acid (TA) showed the chelation capability of Zn 2+ -TA is stronger than that of Zn 2+ -zincon. Thus zincon/ZSHS/TA presented a yellow color due to the chelation reaction of Zn 2+ -TA, releasing the zincon as a free state. After addition of Cu 2+ , a stronger chelation reaction of Cu 2+ -zincon occurred. This process involved in the color change from yellow to blue and realized colorimetric measurement of Cu 2+ . The detection limit of Cu 2+ was calculated to be 43.7 nM with linear range from 0.1 to 20 μM. In addition, the zincon/ZSHS nanoprobe was successfully applied for simultaneous measurement of Cu 2+ and Cr 3+ in sorghum and river water, indicating that the zincon/ZSHS nanoprobe provided a promising sensing platform in environment and food safety.
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PubMed
高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2020
·Vol. 27
·期 14
·16745-16753
·
IF 3.056
Yu Cheng,Zhang Yi,Fang Yu,Tan Yujie,Dai Ke,Liu Shilin,Huang Qiaoyun
Shewanella oneidensis MR-1 (MR-1)-impregnated alginate capsules with 3D porous structure were prepared through cation crossing-linking and was used for the Cr(VI) reduction and removal. After being encapsulated by alginate, the endurance of the MR-1 was largely enhanced under conditions of high Cr(VI) concentrations (up to 4 mM) and low pH (pH 5). The Cr(VI) reduction over the MR-1-impregnated alginate capsules could be fitted by pseudo first-order kinetic model. With the Cr(VI) initial concentration increasing from 1 to 4 mM, the first-order rate constant for the encapsulated MR-1 ( k capsules ) and free cells ( k cells ) fell by 26.3% and 82.4%, respectively. At pH 5, the k capsules value was 0.19 h − 1 , which was about 3.7 times higher than k cells . Moreover, the encapsulated MR-1 held 90.5% of the Cr(VI) reduction ability after 15 days of resting time, while the free MR-1 held 19.7%. After bioreduction, 73.6% of total chromium was adsorbed on the MR-1 impregnated Ca-alginate capsules. XPS results showed 85% of the adsorbed chromium was Cr(III). The mechanism for chromium removal over the MR-1-impregnated Ca-alginate capsules was proposed with the following steps: (1) Cr(VI) was bioreduced via the encapsulated MR-1; (2) the reduced soluble Cr(III) was adsorbed by alginate selectively. In the study, the Ca-alginate shell of the cabbage-like MR-1 impregnated capsules could be a shelter for encapsulated MR-1 to endure unfavorable conditions (e.g., low pH and high concentration of Cr(VI)) and immobilize the soluble chromium. Considering the obtained capsules derived from biomolecules were environment-friendly, the MR-1-impregnated Ca-alginate capsules were potential for the application in the remediation of environmental pollution.
Graphical abstract
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Environmental Technology & Innovation
·
2025
·
IF 7.1
Yonglin Yang,Jiangyong He,Shuaige Shi,Long Yan,Jian Li,Xiaoyong Fan,Bi Chen,Guohui Dong,Hongrui Ma
There is a key issue about formation of highly toxic and easily dissoluble Cr(VI) during heat treatment of Cr-bearing solid waste, resulting in a prominent increase of environmental risk of incineration product. In this study, the effects of CaO and SiO 2 on formation and reduction of Cr(VI) were investigated during heating of Cr-bearing simulated sludge (Cr-SS) and Cr 2 O 3 , exploring Cr(III) oxidation mechanism. The findings indicates that doping CaO significantly promotes Cr(III) oxidation to Cr(VI), and chromium speciation vary with temperature. At 300℃, leaching amount of Cr(VI) in Cr-SS samples increases sharply to 9.3 % of total Cr. In contrast, no Cr(VI) was detected in Cr 2 O 3 samples. Above 300℃, oxidation rates of Cr(III) in different samples of Cr-SS and Cr 2 O 3 exhibit the same trend with temperature increasing. Above 1000℃, new Cr-containing crystalline phases were observed, like CaCr 2 O 4 and Ca 3 (CrO 4 ) 2 . The oxidation rate of Cr(III) is positively connected with the adding amount of CaO. Besides, doping SiO 2 to sludge prominently inhibits Cr(III) oxidation or facilitate Cr(VI) reduction at 600℃-1200℃, which is also confirmed by thermodynamic calculation, attributing to formation of Ca 5 Cr 2 SiO 12 and CaCr 2 O 4 . The number of holes in valence band will be changed through substitution of Cr(III) ions by cations of different valence states, thus facilitate or inhibit Cr(III) oxidation. The ions (III) can inhibit Cr(III) oxidation and promote Cr(VI) reduction. Introducing SiO 2 or Si-enriched materials to chromium-bearing wastes may be a promising alternative to solve the problem of highly toxic Cr(VI) formation during heat treatment.
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高影响因子
RSC Advances
·
2017
·Vol. 7
·期 60
·37778-37786
·
IF 3.108
Shuibin Cen,Weiming Li,Rong He,Jiean Tan,Haishui Wang,Chaohai Wei,Youwen Tang
We developed an effective and selective method to remove Cr(III) ions in acidic effluents. This method used combined ion imprinted technology with mesoporous silica materials. Cr(III) ion imprinted mesoporous silica (CrIMS) was synthesized and used as an excellent adsorbent. Iminodiacetic acid (IDA) was silanized, and acted as a functional monomer. The chemical groups, thermal stability, porosity and highly ordered morphology of CrIMS were characterized by Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), Brunauer–Emmett–Teller (BET) isotherms, X-ray diffraction (XRD), transmission electron microscopy (TEM) and scanning electron microscopy (SEM). The Brunauer–Emmett–Teller (BET) surface area was 856.24 m2 g−1. The saturated adsorption capacity of CrIMS towards Cr(III) ions reached up to 63 mg g−1 at pH 4.5. At a concentration of 200 mg L−1, the adsorption of Cr(III) ions reached equilibrium within 5 min and 20 min at pH 4.5 and pH 3.0, respectively. The CrIMS showed highly specific adsorption capacity and the imprinting factor was up to 4.03 at pH 3.0. The adsorption capacity of Cr(III) ions was remarkably higher than other co-existing metal ions. After eight adsorption–regeneration cycles, the adsorption efficiency of CrIMS still reached above 94.1%. The CrIMS could effectively remove Cr(III) ions below the discharge standard of China in real sample treatment.
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CHINESE JOURNAL OF CHEMICAL ENGINEERING
·
2024
·
IF 3.7
Zhi Hu,Jiahong Wang,Tongtong Sun
A novel tetraethylenepentamine (TEPA) functionalized magnetic mesoporous silica adsorbent (FNMs/TEPA) was prepared for adsorption of Cr(III)-EDTA from wastewater. Characterization of the prepared adsorbent certified that TEPA was modified onto the magnetic mesoporous silicon (FNMs), while FNMs/TEPA maintained the ordered mesoporous and pristine magnetic properties. The batch adsorption experiments demonstrated that TEPA significantly enhanced the removal capacity of the adsorbent for Cr(III)-EDTA. FNMs/TEPA exhibited an excellent adsorption property (13.84 mg∙g –1 ) at pH 4.0. Even in the existence of high concentrations of coexisting ions and organic acids, the adsorption performance of FNMs/TEPA was stable. Experimental characterization and density functional theory (DFT) demonstrated that the adsorption of Cr(III)-EDTA was ascribed to the electrostatic interaction, hydrogen bonding, and complexation between Cr(III)-EDTA and amino groups on the adsorbent surface. The analysis of the Independent Gradient Model (IGMH) shown that electrostatic interaction is the main mode of action in the adsorption process. Moreover, FNMs/TEPA demonstrated remarkable reusability in three regeneration cycles. These findings indicated that FNMs/TEPA possessed excellent application prospect in the disposal of wastewater containing Cr(III)-EDTA.
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SEPARATION AND PURIFICATION TECHNOLOGY
·
2025
·
IF 9
Yabin Wang,Ronghao Wang,Xiuping Ding,Hua He
Hexavalent chromium has seriously destroyed the natural environment and threatened human health. It is crucial but still challengeable to dispose of Cr(VI) handily and recycle the as-generated Cr-based byproducts. Herein, on the one hand, we demonstrate a feasible strategy for cyclic utilization of Cr(VI) species by converting them from toxic to trash and further to treasure. Multiamino-functionalized dendritic mesoporous silica nanoparticles (DMSNs) can adsorb chromium oxyanion ions (HCrO 4 − and Cr 2 O 7 2– ) and in situ reduce Cr(VI) to Cr(III). The as-obtained DMSNs-Cr(III) function as supported catalysts and efficiently catalyze some cross-coupling reactions. On the other hand, pore-size-dependent adsorption of HCrO 4 − and Cr 2 O 7 2− has been realized by regulating DMSNs’ channel size. Furthermore, pore-size-dependent adsorptive and catalytic performances have been demonstrated as well. Our results not only provide a blueprint for cyclic utilization of Cr(VI) in sewage, but also exhibit a versatile DMSNs-based platform that couples with potential structure–activity correlations.
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