CHEMICAL ENGINEERING JOURNAL
·
2023
·
IF 15.1
Hao Zhou,Yongheng Shi,Lingmei Dai,Dehua Liu,Wei Du
Pyrolyzing ZIF-8 into N-doped carbon is now inspiring new potential of ZIF-8 for extensive applications. However, the exploration of such ZIF-8-derived carbon for biotechnological applications has been rarely investigated, especially in this context that imidazole derivatives are of rich functionality in life science. Herein, we reported a facile temperature-dependent pyrolysis method to achieve the effective N-doping in ZIF-8-derived macroporous carbon, which was systematically investigated for the immobilization of lipase from Thermomyces lanuginosus (TLL) in biodiesel production. MNC-600 (macroporous N-doped carbon derived at 600 °C) exhibited the best immobilization performance, with the highest specific activity of 190.6 U mg −1 , a 36.9% increase than free TLL. Moreover, MNC-600@TLL showed superior effectiveness and robustness in biodiesel production. A much faster rate of conversion and the highest biodiesel yield of 87.4% were observed. After eight successive batches of recycling, MNC-600@TLL retained 93.4% of its initial activity. XPS analysis revealed the evolution of N species during the pyrolysis of ZIF-8. It was proposed that the abundant doping of pyrrolic N species played a major role in the surprising performance of MNC-600, mainly through hydrogen bonding interactions, which simultaneously realized the activation of reactants as well as the in-situ hydrophobization of biocatalyst. This report is anticipated to pave a way for the exploration of ZIF-8-derived N-doped carbon for extensive biotechnological applications.
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2023
·
IF 9.5
Wenfu Lin,Yan Huang,Zhenru Li,Jiongshen Pan,Tiansheng Huang,Lili Liang,Yanzhen Tan,Jie Li,Li-Peng Sun,Bai-Ou Guan
Humidity plays an important role in many fields, and the realization of high sensitivity and fast response simultaneously for humidity detection is a great challenge in practical application. In this work, we demonstrated a high-performance relative humidity (RH) sensor made by supporting zeolitic imidazolate framework-90 (ZIF-90)-derived porous zinc oxide (ZnO) onto an optical microfiber Sagnac interferometer (OMSI). The ZIF-90-modified OMSI (ZIF-90-OMSI) sensor was in situ heated at different temperatures to obtain porous ZnO, and their humidity-sensing properties were investigated ranging from 25 to 80% RH. The experimental results showed that the porous ZnO fiber sensor prepared at 500 °C (Z500-OMSI) exhibited best humidity-sensing performance with a high sensitivity of 96.2 pm/% RH (25–45% RH) and 521 pm/% RH (50–80% RH) and ultrafast response/recovery time (62.37/206.67 ms) at 22.3% RH. These performances were attributed to the complete transformation of ZIF-90 to ZnO at 500 °C. The obtained Z500 not only retained the high porosity and specific surface area of ZIF-90 but also exhibited the exceptional hydrophilicity of ZnO. In addition, the signals of the proposed Z500-OMSI sensor changed with different breathing patterns, indicating the possibility for human respiration monitoring. This work provided a reliable candidate for an effective RH monitoring system with potential application in medical diagnoses, industrial production, environmental detection, and human health monitoring.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
·
2023
·Vol. 148
·期 18
·9547-9560
·
IF 4.4
Yang Xuhui,Jiang Siyu,Zhang Zhiyong,Li Bin,Xu Miaojun
Herein, zeolite imidazolate frameworks-67 defined as ZIF-67 was prepared and confirmed. The obtained ZIF-67 was served as a synergist in intumescent flame-retarded polypropylene (PP) composites to improve the flame retardant efficiency and smoke suppression performance. The results of thermogravimetric analysis indicated that the residual char of IFR/ZIF-67 with the mass ratio of 95:5 greatly enhanced from 24.9 mass% for IFR to 63.5 mass%, and increased by 155.0%. It was ascribed the complexation effect of cobalt ion in ZIF-67 for IFR system. With the incorporation of 18 mass% IFR/ZIF-67, the PP/IFR/ZIF-67 samples (PP-4) achieved UL-94V-0 rating during vertical burning tests and the limiting oxygen index (LOI) value was as high as 31.1%. Compared with PP/IFR (PP-1) containing 18 mass% IFR, the peak heat release rate (peak-HRR), total heat release (THR), peak smoke production rate (peak-SPR) and total smoke production (TSP) of PP-4 were decreased by 33.1%, 33.8%, 31.0% and 21.1%, respectively. The char residue of PP-4 was as high as 27.4 mass% at the end of cone calorimeter test (CCT). The more expanded, sufficient and dense char layer were generated during combustion, and the flame retardancy and smoke suppression of PP-4 were significantly improved. Meanwhile, the pyrolysis gaseous products were inhibited to enter into combustion zone due to the isolation effect of the generated intumescent char layer. Consequently, the PP/IFR/ZIF-67 composites with excellent flame retardant performance and smoke suppression were obtained.
✓ 已验证
产品关联
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2022
·Vol. 46
·期 38
·18295-18305
·
IF 3.925
Zi Dai,Jilin Zhang,Xiaoya Zhao,Xiaoxun Liu,Yunyun Lei,Guixia Liu
Removal of phosphate from wastewater by adsorption has become one of the effective ways to mitigate the negative effects of eutrophication in water bodies, and efficient adsorbent is the key. In this study, MgAl-LDH@ZIF-8 composites were prepared by in situ growth of zeolite imidazole framework-8 (ZIF-8) on layered double hydroxide (MgAl-LDH) for efficient removal of phosphates in wastewater. Compared with pure ZIF-8 and MgAl-LDH, MgAl-LDH@ZIF-8 has higher phosphate removal efficiency of up to 99%. Its maximum adsorption capacity was 68.53 mg P g−1. The adsorption process conformed to the pseudo-second-order kinetic model and Langmuir isotherm model. The thermodynamic results indicate that the adsorption process is spontaneous and endothermic. The adsorption mechanism is mainly electrostatic attraction, ion exchange, and ligand exchange. The MgAl-LDH@ZIF-8 with the dosage of 2.5 g L−1 can remove 30 mg P L−1 of simulated wastewater containing phosphate and meets the discharge standard of the U.S. Environmental Protection Agency (0.5 mg P L−1). The results show that MgAl-LDH@ZIF-8 is an effective adsorbent for the removal of phosphate from wastewater, with potential for practical applications.
✓ 已验证
产品关联
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2022
·
IF 5.518
Xianjin Gong,Jie Wang,Ying Shi,Qiang Zhang,Weixing Liu,Shan Wang,Jinlei Tian,Guichang Wang
Aqueous zinc ion batteries (AZIBs) are considered as one of the most promising alternatives for lithium-ion battery because of its high theoretical capacity, mild reaction with water, high hydrogen evolution potential and abundant natural reserves. However, the growth of anode dendrite and the attenuation of cathode capacity limit the application of zinc ion battery. Here, we propose that ZIF-8 can be used as an electrolyte additive for AZIBs to promote dendrite-free zinc anodic plating/stripping process. The results show that under the action of uniform ionic flux of ZIF-8, the zinc anode achieves a lifetime of more than 550 h, and significantly inhibits the occurrence of positive side reactions (106.1 mAh g −1 after 500 cycles at a current density of 1 A g −1 ). Density functional theory was used to systematically calculate the binding energy of Zn 2+ to different pore sizes of ZIF-8 and the results reveal that the adsorption capacity of ZIF-8 can control the migration of Zn 2+ . This work expands the application of MOFs in AZIBs and opens up a new door for future research about AZIBs based on MOFs.
✓ 已验证
产品关联
DOI
高影响因子
ChemistrySelect
·
2022
·Vol. 7
·期 36
·e202203273
·
IF 2.307
Jingting Qiu,Xiang Xu,Baogen Liu,Yang Guo,Huijun Wang,Lingyun Yu,Yuwei Jiang,Changsheng Huang,Binfeng Fan,Zheng Zeng,Liqing Li
Graphical Zeolitic imidazolate frameworks-8 (ZIF-8) with different average sizes (50, 120, and 2200 nm) is successfully prepared. Carbonization is proved to be an effective method to adjust the aperture for derived porous carbon of ZIF-8. Among them, ZC50 possesses narrow micropore in range of 0.7–1.0 nm, located in the optimal pore size range of CO 2 adsorption. Besides, ZC120 exhibits more superior mesopore structure that could strengthen VOCs adsorption. It's acknowledged that surface chemical and pore structure of adsorbent are main parameters to determine adsorption results. Herein, we prepared zeolitic imidazolate frameworks-8 (ZIF-8) with different average sizes (50, 120, and 2200 nm) and demonstrated their specific surface area and pore volume decreased with increasing particle size. ZIF-8 (ZN) exhibits a large specific surface area (1626.4 m 2 g −1 ) and total pore volume (1.088 mL g −1 ), but it has been shown to lack the non-specific adsorption capacity for the adsorbate. Carbonization at 800 °C is proved to be an effective method to expose massive surface nitrogen-containing functional groups and adjust the aperture to an appropriate pore size range for derived porous carbon of ZIF-8 (ZCN). High nitrogen content (18.7 at. %) greatly improves the affinity for CO 2 and Volatile Organic Compounds (VOCs), as explained by the density functional theory (DFT) calculation results. Meanwhile, particle size influences the pore-forming results after carbonization directly. Among them, ZC50 generates a certain amount of narrow micropore in range of 0.7–1.0 nm, located in the optimal pore size range of CO 2 adsorption calculated by Grand canonical Monte Carlo (GCMC) simulation, thus possessing the largest CO 2 adsorption capacity (4.03 mmol g −1 at 25 °C). Besides, ZC120 exhibits more superior mesopore structure that could strengthen multilayer adsorption for VOCs.
✓ 已验证
产品关联
DOI
高影响因子
MICROPOROUS AND MESOPOROUS MATERIALS
·
2022
·
IF 5.876
Chengyuan Duan,Yi Feng,Yuming Xie,Meili Ding,Jianfeng Yao
A facile one-step synthetic strategy is proposed here to realize simultaneous amine-functionalized and Fe-doping modification of ZIF-8, aiming to optimize the Lewis acidic and basic properties of ZIF-8 for enhanced CO 2 adsorption and subsequent cycloaddition reaction of CO 2 and epichlorohydrin under solvent-free and relatively mild conditions (0.1 MPa and 80 °C). The obtained Fe-ZIF-8-NH 2 exhibits an improved CO 2 adsorption capacity of 63 mmol/g as compared to that of 18 mmol/g for pristine ZIF-8 and delivers a high catalytic CO 2 cycloaddition efficiency with the yield of target product of 92%, much higher than that of Fe-ZIF-8 (80%), ZIF-8-NH 2 (62%) and pristine ZIF-8 (40%). The improved performance can be attributed to the introduction of abundant –NH 2 groups and Fe-doping that enrich the Lewis acidity and basicity. Moreover, the obtained Fe-ZIF-8-NH 2 also exhibits high chemical stability and satisfactory recycling ability, which makes the obtained sample a promising catalyst for CO 2 capture and utilization.
✓ 已验证
产品关联
DOI
高影响因子
ChemCatChem
·
2022
·Vol. 15
·期 1
·e202201234
·
IF 5.497
Lu Lin,Guikai Zhang,Liqun Kang,Tao Yu,Yang Su,Guang Zeng,Shengqi Chu,Wenhao Luo
Graphical Methane oxidation : Highly dispersed mononuclear Fe species encapsulated by ZIF-8 (Fe-ZIF-8) afford an optimal turnover rate of ∼45 mol C1 mol Fe −1 h −1 and a formic acid selectivity of ∼97 % in the direct methane oxidation at 323 K. The direct catalytic oxidation of methane into C1 oxygenates is a promising approach for methane valorization. However, the difficulties in CH 4 activation and inhibition of over-oxidation hinder the development of efficient catalysts for this transformation. Herein, highly dispersed Fe species confined by ZIF-8 are developed for the direct transformation of methane into value-added C1 oxygenates with H 2 O 2 as oxidant at 323 K. The as-obtained Fe-ZIF-8 can afford an optimal turnover rate (TOR) of ∼45 mol C1 mol Fe −1 h −1 . Note that the selectivity to HCOOH is ∼97 %, outstanding among the reported Fe-based heterogeneous catalysts. Combined analysis of X-ray photoelectron spectroscopy, X-ray absorption spectroscopy, ultraviolet-visible diffuse reflectance spectroscopy and 57 Fe Mössbauer spectroscopy suggests that the catalytically active sites in Fe-ZIF-8 are mononuclear six-coordinated Fe 3+ species. The confinement of mononuclear Fe species within a porous metal-organic framework material can provide an exquisite, enzyme-like performance for highly selective oxidation of methane towards formic acid under mild conditions.
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MOLECULAR LIQUIDS
·
2022
·
IF 6.633
Tingting Chen,Yingjie Xu,Bin Chen,Huiquan Xiao
In this work, the efficient preparation of zeolitic imidazolate framework-8 (ZIF-8) from Zn 2+ and 2-methylimidazole (2-MI) promoted by 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) was presented. The mechanism obtained from NMR, MS, DFT calculations, and conductivity shows that [DBUH][2-MI] ionic liquid formed in-situ from proton transfer between DBU and 2-MI can ionize 2-MI to [2-MI] - and form electrostatic interaction between Zn 2+ and [2-MI] - , resulting in the efficient self-assembly of Zn 2+ and 2-MI to form ZIF-8. Moreover, the effect of the amount of DBU on ZIF-8 indicates that too much DBU will cause excessive deprotonation of 2-MI, leading to agglomerate of ZIF-8. Accordingly, the optimal ratio to form ZIF-8 is n(DBU): n(2-MI): n(Zn 2+ ) = 2: 25: 1.25, which is also employed to prepare cerium-containing ZIF-8. Moreover, ZnO and Ce/ZnO nanomaterials are prepared by using ZIF-8 and cerium-containing ZIF-8 as precursors respectively, and their structure and morphology are characterized by XRD, FT-IR, SEM, and TEM. Interestingly, Ce content in Ce/ZnO obtained by EDS spectrum is basically consistent with the actual doping amount, indicating that DBU can effectively control the doping of Ce in ZIF-8. Finally, the photocatalytic degradation ability of ZnO and Ce/ZnO for Rhodamine B under visible light and sunlight is investigated in detail.
✓ 已验证
产品关联
DOI
高影响因子
Arabian Journal of Chemistry
·
2022
·
IF 6.212
Jiacheng Li,Lisha Liao,Yannan Jia,Tian Tian,Shiwei Gao,Chenyue Zhang,Wei Shen,Zheng Wang
In this study, the preparation of magnetic Fe 3 O 4 /ZIF-8 (MFZ) and its adsorption properties for Cd(II) from water were investigated. Various characterizations demonstrate that the as-prepared MFZ has well magnetic-separation performance and thermal stability. In batch adsorption tests, the effects of pH, initial concentration, and adsorbent dosage were evaluated. According to the findings, when the pH is 7 and the dosage is 150 mg/L, the adsorption capacity for a 40 mg/L Cd(II) solution reaches 102.3 mg/g in 180 min. The Cd(II) adsorption processes was found to correspond to pseudo-first-order kinetics and Langmuir model according to the adsorption kinetics and isotherms. The Langmuir model predicted a maximal saturation adsorption capacity of 160.26 mg/g at 298 K. Thermodynamic analysis revealed that the Cd(II) adsorption is an endothermic, spontaneous process. Ion exchange, coordination reaction, and electrostatic interaction are all involved in Cd(II) adsorption by MFZ. The optimum conditions for Cd(II) adsorption were proposed and confirmed in accordance with the results of the response surface optimization experiments. Furthermore, regeneration tests demonstrate the great repeated regeneration ability of MFZ. According to the anticipated production cost, treating wastewater with a Cd(II) concentration of 40 mg/L would cost roughly US$ 8.35/m 3 . MFZ showed good potential for Cd(II) removal from water.
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2022
·
IF 16.744
Jinlai Shen,Zhiwen Lei,Chaoyang Wang
Solid polymer electrolyte with broad electrochemical stability window is regarded as the most promising candidate for high-voltage lithium metal batteries enabling high specific energy density. However, solid polymer electrolyte without particular protection is not facile to realize stable cycle of LiNi 0.8 Co 0.1 Mn 0.1 O 2 (NCM811) cathode at high voltage because of the strong oxidizing property from the direct contact between cathode and electrolyte. Herein, an ion conducting asymmetric poly(ethylene oxide) (PEO) based electrolyte composed of zeolitic imidazolate framework (ZIF-8)@ionic liquid protective coating on NCM811 cathode surface and PEO-based electrolyte with ZIF-8 nanofillers on lithium metal anode is prepared in order to construct high-performance solid-state lithium metal batteries. The as-prepared asymmetric composite electrolyte exhibits a high ionic conductivity of 9.02 × 10 -4 S/cm at 60 °C and broad electrochemical stability window of above 4.9 V. Notably, the as-prepared cells exhibit the highest discharge capacity of 150 mAh/g at 0.2C under 60 °C. It is found that the ZIF-8@ionic liquid protective coating effectively prevents the oxidative decomposition of PEO based electrolyte at high voltage and the transition metal dissolution from the cathode. Meanwhile, the growth and penetration of lithium dendrites are also restrained, which shows significant potential for boosting the commercialization of high-voltage lithium metal batteries.
✓ 已验证
产品关联
DOI
高影响因子
CHEMOSPHERE
·
2022
·
IF 8.943
Long Zhou,Yunqiang Yi,Zhanqiang Fang
nZVI is considered to be a promising material for environmental remediation. However, the drawbacks of easy agglomeration and low activity severely limit its application. In this work, nZVI/ZIF-8 was obtained by in-situ reduction of nZVI in the presence of performed ZIF-8. The reactivity of the as-obtained nZVI/ZIF-8 nanocomposites was investigated by removing hexavalent chromium (Cr(VI)) from wastewater. The as-obtained nZVI/ZIF-8 nanocomposites showed a superior activity for Cr(VI) removal, with an optimum activity (91.27%) achieved over 0.25 nZVI/ZIF-8 (i e., the mass ratio of ZIF-8 to nZVI was 0.25), higher than that of nZVI (64.55%), and this could be owned to the excellent dispersion of nZVI in nZVI/ZIF-8 and the high specific surface area as compared with the bare nZVI. The results of XPS characterization, quenching experiment analysis and kinetics fitting indicated that the Cr(VI) elimination was a surface-dominated chemical reduction process. Besides, more than 99.00% Cd(II), Cu(II), Cr(VI) and Pb(II) was removed from wastewater over nZVI/ZIF-8 nanocomposites, and negligible zinc ion was detected in the aqueous solutions. The results of our finding demonstrate that the introduction of MOFs is an effective strategy in developing a highly efficient nZVI-based nanocomposites system, and also highlight the promising role of using nZVI/MOFs in heavy metal treatment for practical wastewater.
✓ 已验证
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）