CARBOHYDRATE POLYMERS
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2023
·
IF 11.2
Yanxiao Yang,Yunfeng Guo,Zhe Qiu,Weihua Gong,Yonggui Wang,Yanjun Xie,Zefang Xiao
Metal-organic frameworks (MOFs) are characterised by high porosity levels and controllable structures, making them ideal adsorbents for wastewater. However, obtaining substrate materials with mechanical stability, excellent pore accessibility, and good processability for compositing MOF crystal powders to adsorb multiple pollutants in complex aqueous environments is challenging. In this study, porous MOFs@ modified cellulose sponge (MCS) composites were fabricated using MCS as a scaffold to provide anchoring sites for the coordination of Zr 4+ ions and further in situ synthesis of MOFs, namely UiO-66@MCS and UiO-66-NH 2 @MCS, which effectively removed heavy metal ions and organic dyes. MOFs@MCS composites exhibit excellent water and dimensional stability, maintaining the pore structure by ambient drying during reuse. Compared with UiO-66@MCS composite, UiO-66-NH 2 @MCS composite exhibited a higher adsorption capacity of 224.5 mg·g −1 for Hg 2+ and 400.9 mg·g −1 for methylene blue (MB). The adsorption of Hg 2+ onto the MOFs@MCS composites followed the Langmuir and pseudo-second-order models, whereas the Freundlich and pseudo-second-order models were more suitable for MB adsorption. Moreover, the MOFs@MCS composites exhibited excellent reusability and were selective for the removal of Hg 2+ . Overall, this approach effectively combines Zr-based MOFs with mechanically and dimensionally stable porous cellulose sponges, rendering the approach suitable for purifying complex wastewater.
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高影响因子
Journal of Materials Chemistry A
·
2023
·Vol. 12
·期 6
·3565-3574
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IF 11.9
Ling-Chan Tian,Geqian Fang,Yun Zhou,Wenjun Yu,Lin Li,Jin-Nian Hu,Haiyan Wang,Jin-Xia Liang,Chun Zhu,Xiaodong Wang,Jian Lin
Direct selective oxidation of methane (DSOM) to oxygenates under mild conditions is garnering increasing interest. UiO-66-H MOFs are effective for this reaction, while the active configuration of Zr-oxo nodes with adsorbed ˙OH species need further clarification from the atomic/molecular viewpoint. Here, we detect the evolution of the geometric and electronic structures of adsorbed oxygenic species on Zr-oxo nodes of UiO-66-H via the controlled ˙OH species. DFT calculations reveal a volcano-like curve relationship between the quantity of ˙OH species and the DSOM performance, which is further corroborated by experimental tests. Zroxo-˙OH is the main active configuration on Zr-oxo nodes of UiO-66-H at low ˙OH concentration, while it evolves to other oxygenic species (˙OOH, O2, and H2O) due to the self-reaction with the increase of ˙OH concentration, which leads to performance decrease. Furthermore, a critical descriptor of the p-band centers of O atoms in these oxygenic species on the Zr-oxo nodes is established, which can well represent the catalytic activity for the DSOM reaction.
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CHEMICAL ENGINEERING JOURNAL
·
2020
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IF 10.652
Jiali Tang,Jiling Zhao,Shixing Wang,Libo Zhang,Minghu Zhao,Zhen Huang,Yuting Hu
In this study, a novel metal organic framework (MOF) was prepared by pre-modification strategy and used as adsorbents to recover palladium ions in wastewater. The characterization indicates that the adsorbents have been successfully synthesized. The effects of various factors on the adsorption behavior of the adsorbents for Pd(II) was studied. Experimental research shows that the optimal pH of the adsorption process is 4.0. The adsorption kinetics and isotherms of Pd(II) on the adsorbents show that it conforms to pseudo-second-order and Langmuir models, respectively. Therefore, the adsorption reaction is a single layer adsorption on the uniform surface of the adsorbent, and chemical adsorption is the main rate-limiting step. According to thermodynamic analysis, the adsorption process is entropiezunahme, spontaneous and endothermic. The adsorption mechanism of Pd(II) on the adsorbents is mainly through the electrostatic action and chelation of Pd(II) with N and O atoms, and the reduction of Pd(II) to Pd(0) by N and O functional groups. The adsorbents can selectively uptake palladium ions from multi-ion wastewater, and after five adsorption–desorption cycles, the adsorption efficiency is still high. This new adsorbent has a wide application prospect in the field of palladium ion separation.
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RSC Advances
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2020
·Vol. 10
·期 68
·41283-41295
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IF 3.119
Ahmed S. Abou-Elyazed,Yinyong Sun,Ahmed M. El-Nahas,Ahmed M. Yousif
Recently, the incorporation of hydrophobicity on the surface of UiO-66(Zr) has received much attention due to the deactivation of hydrophilic active sites of UiO-66(Zr) upon water adsorption. In this work, we report UiO-66(Zr) catalysts with an assortment of surface hydrophobicities fabricated by the solvent-free method to elucidate the impact of the environment framing Lewis acid sites on their catalytic activity in the production of fatty acid methyl ester (biodiesel) via the esterification of fatty acids at room temperature with high selectivity (100%) and good recyclability. A detailed structural analysis of the materials by N2 sorption, FT-IR, SEM, XRD, water contact angle measurement, dynamic liquid scattering (DLS), NMR and TGA revealed the fabrication of stearic acid-grafted UiO-66(Zr) catalysts (10SA/UiO-66) with fine particle size and a highly hydrophobic network. 10SA/UiO-66(Zr) with enhanced hydrophobicity exhibited superior catalytic performance in the esterification of a fatty acid with a long alkyl chain compared with conventional solid acid catalysts and even liquid acid catalysts. Detailed kinetic studies corroborated that the adsorption of lipophilic acids at the Lewis acid sites besides the enhancement of wettability between the reactants was facilitated by the hydrophobic environment, thus significantly motivating the esterification reaction at room temperature. Furthermore, 10SA/UiO-66(Zr) showed good catalytic activity in the esterification of oleic acid in the presence of water (∼10% in the light of acid weight).
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CHEMICAL PHYSICS
·
2021
·
IF 2.348
Xingchang Tang,Yongwei Luo,Zhijian Zhang,Wanwu Ding,Dexue Liu,Jingchuan Wang,Li Guo,Ming Wen
The high surface areas and tunable properties of Zr-based MOFs make them as attractive materials for gas capture, storage, and separation. In this work, UiO-66, one kinds of Zr-based MOFs, functionalized by single or binary –NO 2 and –NH 2 groups are synthesized. Water adsorption ability and hydrophilicity of UiO-66 and functionalized UiO-66-X were investigated. It is found that surface area of UiO-66 is decreased after introducing functional groups, while hydrophilicity of UiO-66 increased after functionalized with –NO 2 and –NH 2 . Therefore, after balance the effects of surface area and hydrophilicity, UiO-66-NH 2 shows the best water adsorption propriety.
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MICROPOROUS AND MESOPOROUS MATERIALS
·
2021
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IF 5.455
Mengmeng Zhang,Jiaying Lou,Rui Xu,Peng Li,Yunfei Sha,Hui Zhang,Yu Jia,Zhenxia Chen,Da Wu,Yun Ling,Yaming Zhou
Metal-organic frameworks (MOFs) featuring a fcu-type net based on 12-connected [Zr 6 (μ 3 -O) 4 (μ 3 -OH) 4 ] cluster have received considerable interest for the fundamental investigation of structure-property relationships in a wide range of catalytic reactions . In this work, the bipyridine (bpy) chelate group was introduced into the fcu-type framework of UiO-67, giving UiO-67bpy as the catalyst support. Then, FeCl 3 was post-synthetically anchored to the bpy group, resulting into the isolation of FeCl 3 /UiO-67bpy. Catalyzed hydrolysis of 5-hydroxylmethoxyfurfural (HMF) into levulinic acid (LA) was then explored and revealed that it can efficiently and selectively catalytic convert HMF into LA, which is superior to that of FeCl 3 /UiO-67 where FeCl 3 is encapsulated in the cage of UiO-67 and dispersed on the pore surface. The recyclability studies further confirmed the importance of anchored FeCl 3 where there is no significant decrease in catalytic activity as compared with that of FeCl 3 /UiO-67. Taking the detailed textural porosity and catalytic results of isomorphous structures in consideration, our studies revealed that narrowing the pore size with anchored FeCl 3 on the skeleton of the fcu-type Zr-MOF rather than encapsulating FeCl 3 inside the cage is more favored for the rehydration reaction of HMF to LA.
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Environmental Science-Nano
·
2019
·Vol. 6
·期 12
·3590-3600
·
IF 7.704
Yunyun Xu,Jiaxin Lv,Yao Song,Xiaoyu Zhou,Chen Tian,Xujia Hong,Yuepeng Cai,Cunyuan Zhao,Zhang Lin
As an emerging micropollutant, organoarsenic has caused global ecosystem pollution, due to its degradation to highly toxic inorganic arsenic in the environment. Therefore, to remove the low-concentration organoarsenic from arsenic compounds from water, materials with high adsorption affinity are in urgent need. Herein, we reported an amino-modified metal–organic framework (MOF) with defects (UiO-66-D-NH2) to adsorb two typical organoarsenic forms p-arsanilic acid (p-ASA) and roxarsone (ROX). The adsorption affinity of UiO-66-D-NH2 was 3.8 and 3.0 times higher than that of original UiO-66 and defective UiO-66 without amino modification (UiO-66-D), while the removal rate exceeded 99.1% when the initial concentration of organoarsenic decreased to 1 mg L−1. UiO-66-D-NH2 also showed excellent adsorption behavior in simulated wastewater, with residual arsenic concentrations lower than 0.54 μg L−1. Mechanism studies showed a cooperation of the defects and –NH2 groups in UiO-66-D-NH2. The defects provided more Zr–OH sites in the metal node, leading to transformation of the As–O–Zr coordination from monodentate mononuclear to bidentate binuclear configuration, while –NH2 groups formed hydrogen bonds with both p-ASA and ROX as a secondary interaction to further reinforce the as-formed As–O–Zr complex. This work revealed that making cooperation by defect creation and amino modification could be an effective method to enhance the adsorption affinity of MOFs to low-concentration organoarsenic.
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高影响因子
NEW JOURNAL OF CHEMISTRY
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2019
·Vol. 43
·期 43
·16981-16989
·
IF 3.069
Bingying Jia,Miaojiang Wu,Hua Zhang,Yi Zeng,Gongying Wang
Titanates are frequently used as precursors to prepare transesterification catalysts with TiIV species. Unfortunately, it is challenging to control the dispersity of TiIV active sites on supports. Herein, a series of TiIV species is anchored on abundant linker vacancy sites by introducing point and large scale defects in UiO-66(Zr/Ti) with hierarchical-pore structure. The catalyst functionalized by titanium(IV) oxide bis(2,4-pentanedionate) shows excellent catalytic performance in the transesterification of dimethyl carbonate with phenyl acetate. The catalysts are characterized by XRD, FT-IR, N2 adsorption–desorption, XPS, SEM and STEM-HAADF techniques. The results demonstrate that the delicate mesopores in the support can not only exhibit a large surface area for the distribution of the active sites, but also provide better mass transfer performance. Meanwhile, the introduction of octahedral TiIV ions raises the activity of the catalyst via more coordinatively unsaturated ZrIV sites. Furthermore, using titanium(IV) oxide bis(2,4-pentanedionate) as a Ti source can effectively prevent the condensation of tetrahedral TiIV species anchored on the hierarchical-pore UiO-66(Zr/Ti) support.
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INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2019
·
IF 4.084
Fufeng Cai,Peijing Lu,Jessica Juweriah Ibrahim,Yu Fu,Jun Zhang,Yuhan Sun
Methanol steam reforming is regarded as a very promising process to generate H 2 suitable for fuel cells. Typically, the Pd-based catalysts can catalyze efficiently methanol steam reforming for hydrogen production . But their high selectivity to CO, a byproduct of methanol reforming reaction , severely limits their potential application. In this work, a series of Nb-modified Pd−Zr−Zn catalysts with different Nb loadings were prepared to study their catalytic activities with more focus on the role of Nb on Pd−Zr−Zn catalyst for methanol steam reforming. The prepared catalysts were fully analyzed by using various characterization techniques, for example, ICP , BET, SEM, XRD , H 2 -TPR, NH 3 -TPD, HRTEM , CO chemisorption , XPS, and Raman. The experimental results showed that an increase in Nb loading for the Nb-modified Pd−Zr−Zn catalysts led to a decrease of the methanol conversion and H 2 production rate. This was probably due to the decrease in the amount of oxygen vacancies on the catalyst surface . However, introduction of Nb into Pd−Zr−Zn catalyst increased the acid strength on the catalytic surface. The aldehyde species derived from methanol decomposition were readily transformed to HCOOH, thus yielding high selectivity to CO 2 for the Nb-modified Pd−Zr−Zn catalysts. Significantly, the addition of Nb to Pd−Zr−Zn catalyst facilitated the incorporation of Pd into the ZnO lattices, which led to the formation of Pd−Zn alloy. Consequently, the Nb-modified Pd−Zr−Zn catalysts exhibited significantly lower CO selectivity and production rate than the Pd−Zr−Zn catalyst. From the results, this work offers a new way to the rational design of selective methanol steam reforming catalysts to decrease the formation of byproduct CO.
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ACS Applied Nano Materials
·
2019
·
IF 0
Xian Fang,Xiaoyan Chen,Ying Liu,Qiuju Li,Zhongrun Zeng,T. Maiyalagan,Shun Mao
Rapid determination of trace antibiotics is critical for environmental monitoring and the ecosystem. In this study, a sensitive and selective electrochemical sensor for ciprofloxacin (Cip) detection by anodic stripping voltammetry of Cu2+ is designed. Zr(IV)-based metal–organic framework (MOF) NH2–UiO-66 and reduced graphene oxide (RGO) composites are used as working electrodes, which have a large surface area with porous structure and high electrical conductivity. Because Cip can form a stable composite with Cu2+ due to the complexation reaction, the anodic stripping voltammetry method is used for Cip determination with Cu deposition on the NH2–UiO-66/RGO-modified electrode. When Cip is present, the oxidization current of Cu2+ decreases significantly due to the formation of Cu2+–Cip complex. The prepared NH2–UiO-66/RGO sensor can detect trace levels of Cip down to 6.67 nM with a sensitivity of 10.86 μA μM–1, and a linear working range from 0.02 to 1 μM, which is superior to other electrochemical Cip sensors reported previously. The sensor also shows high selectivity, reproducibility, and stability in Cip sensing. Meanwhile, the electrochemical sensor is capable to detect Cip in real water samples with satisfactory recoveries. The ultrasensitivity, rapid detection, and easy operation of the reported sensors present significant potentials for real-time analysis and monitoring of trace antibiotic contaminants in water.
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CHEMICAL ENGINEERING JOURNAL
·
2019
·
IF 8.355
Chen Wang,Guo Lin,Jiling Zhao,Shixing Wang,Libo Zhang,Yunhao Xi,Xiteng Li,Ying Ying
A novel adsorbent (UiO-66-TA) was presented by modifying metal-organic framework composites with thioctic acid. UiO-66-TA were characterized by fourier transform infrared (FT-IR), field emission scanning electron microscopy (FESEM), thermogravimetric (TG), Brunner-Emment-Teller (BET) measurement and X-ray photoelectron spectroscopy (XPS), which indicating that it had excellent morphology and specific surface area. The adsorption performances of UiO-66-TA for Au(III) were studied. The results showed that UiO-66-TA had a strong adsorption capacity under acidic conditions and the optimal pH was 2.0. Isotherm and kinetic adsorption were also conducted and found that the experimental values correspond to Langmuir model and pseudo-second-order isotherm model, indicating that the mechanism is mainly chemical adsorption on a uniform surface. Wastewater experiment showed that UiO-66-TA can be used for highly selective recovery Au(III) in actual life. The regeneration and thermodynamic experiments indicated that UiO-66-TA can be reused and were a spontaneous endothermic process. XPS analysis and the zeta potential proved that the main adsorption mechanisms were ion exchange and chelation. DFT calculation found that there are two ways to combine Au with S on UiO-66-TA and their distances are 2.38 Å and 2.39 Å, indicating that the gold and sulfur play a major role in chelation. In summary, UiO-66-TA was a hopeful adsorbent and could be used to collect gold ions from wastewater in a sustainability perspective.
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JOURNAL OF CHROMATOGRAPHY A
·
2018
·
IF 3.716
Wenqing Li,Rong Wang,Zilin Chen
A novel metal-organic framework UiO-66-modified cotton was prepared and applied to solid phase microextraction of non-steroidal anti-inflammatory drugs, namely ketoprofen, naproxen and flurbiprofen. UiO-66 was immobilized onto the surface of cotton by a polydopamine functionalized method. The resultant cotton@PDA@UiO-66 was characterized by Fourier transform infrared spectroscopy, X-ray diffraction and scanning electron microscopy. The solid phase microextraction conditions were optimized, including sampling flow rate, formic acid content of the eluent, pH value of sample solution, NaCl content and sample volume. By combining with HPLC, this method showed high extraction efficiency (the enrichment factors of ketoprofen, naproxen and flurbiprofen were 44, 49 and 45, respectively), wide linear range (0.1–500 ng/mL), good linearity with R ≥ 0.9996 and satisfactory sensitivity (LODs ≤ 0.03 ng/mL, LOQs ≤ 0.1 ng/mL), as well as good reproducibility (RSD ≤ 4.51%). This method was also successfully applied to extraction of NSAIDs in swine muscle sample. Good recoveries were obtained, ranging from 88.54% to 95.7% with relative standard deviations less than 3.77%.
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