JOURNAL OF POLYMER SCIENCE
·
2025
·
IF 3.6
Yang Liu,Guodong Cao,Xuelong Zhu,Yi Zhang,Chenglu Liang,Yukun Chen
Upcycling the wasted polyamide 6 (PA6) to its monomer caprolactam via depolymerization is a promising way to build the resource cycling and alleviate the environmental pollution. High efficient catalyst for PA6 depolymerization is desirable and crucial. Herein, a sulfonated Fe-MOF catalyst was designed and performed as solid acid catalyst for the PA6 depolymerization for the first time. Results showed that a 100% conversion of PA6 solid to water-soluble liquid products can be achieved at temperatures of 250°C after only 1-h reaction. LC/MS results indicated that the water-soluble products were mainly composed of caprolactam and their oligomers. Without catalyst, nearly no water-soluble products can be obtained at the same condition. Moreover, a high selectivity of 90% caprolactam production in the water-soluble liquid products was achieved at 260°C, 5 h. The reaction rate constants at 240°C, 250°C, and 260°C were determined to be 0.024, 0.033, and 0.064, respectively, with a Ea value of 101.8 kJ/mol, showing positive temperature dependent relationship. The comparison of catalytic performances over sulfonated Fe-MOFs, FeCl 3 ·6H 2 O and the pristine un-sulfonated Fe-MOF suggested the synergistic contribution of Fe sites (Lewis acid centers) and the sulfonic acid sites to the catalytic performances. Graphical Water soluble liquid products (100 wt.%) with a high selectivity of 90% caprolactam can be achieved by the addition of Fe-MOF catalyst under a mild condition through the synergistic catalytic contribution of Fe sites (Lewis acid centers) and the sulfonic acid sites.
研究领域:
材料科学
·
环境科学
·
催化化学
✓ 已验证
DOI
高影响因子
Journal of Environmental Chemical Engineering
·
2023
·
IF 7.7
Zhenxing Liu,Zhan Hu,Faxiong Li,Xinting Lai,Yuan Zhou,Jiaqi Song,Zhihui Yang,Cong Peng,Fenghua Ding,Junfang Nan,Yexin Zhang,Yanjie Liang
Icosahedral boron arsenide B 12 As 2 is a self-healing semiconductor potentially applied in harshly irradiated environments. However, doping effects were rarely investigated to expand their applications. Hereby, a low-cost mechanochemical strategy is proposed to synthesize B 12 As 2 nanocrystals with a boron transformation rate of ∼70%. Nano-B 12 As 2 of 40–50 nm could be self-doped with Fe element and purified by aqua regia. Fe accounts from ∼0.00–1.77 at% with rotational speeds. Based on nano-size effects and Fe-doping effects, the photoluminescence process shows an indirect band-gap at E g = 2.81 eV and the presence of impurity energy level at E′= 2.11 eV. The optical absorption is red-shifted from the reported UV region to the visible region. The multiply increased photocatalytic hydrogen production (249 μmol∙h −1 ∙g −1 vs. 92.2 μmol∙h −1 ∙g −1 ) and photocurrent density (∼6 times) indicate that Fe-doping enhances the photo-excitement and the separation of the photoinduced carrier. First-principles calculations reveal a robust B 12 As 2 structure doped by Fe, bonding to icosahedral B 12 clusters and its nearest As via the Fe(III) style. Doped-Fe alters HOMO and LUMO orbital components, reduces the optical band-gap and becomes the activated carrier-separation center. Overall, a novel synthetic method and mechanism of Fe-doping are revealed that would facilitate optical applications of B 12 As 2 crystals under extreme conditions.
研究领域:
材料科学
·
半导体物理
✓ 已验证
DOI
高影响因子
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
·
2021
·
IF 4.098
Xiao-Lan Zhao,Jia-Li Liu,Fa-Ting Xie,Tong Yang,Rong Hu,Yun-Hui Yang
In this paper, a simple, rapid, and low-cost colorimetric method was designed based on Co/Fe-MOFs-iodide composite for the quantitative detection of H 2 S. It is know that iodide can improve the catalytic activity of bimetallic porous material Co/Fe-MOFs via adsorption into the framework of MOFs. Herein, we demonstrate a novel strategy to enhance the peroxidase-like activity of MOFs. Compared to horseradish peroxidase (HRP), the kinetic measurement results show that Co/Fe-MOFs-iodide exhibits excellent affinity to substrates, promoting electron transfer. Due to the synergetic effect of Co/Fe-MOFs and iodide, and rapid electron transfer process, Co/Fe-MOFs-iodide demonstrates improved peroxidase-like activity. As a proof-of-concept application, a novel, highly sensitive H 2 S colorimetric method is established with a detection limit (LOD) of 0.33 nM. In the absence of iodide, LOD is approx. 200-fold higher than that of the amplified colorimetric assay. The proposed method can also accurately detect traces of H 2 S in serum samples.
研究领域:
生物化学
·
分析化学
✓ 已验证
DOI
PubMed
高影响因子
METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE
·
2020
·Vol. 51
·期 6
·3090-3103
·
IF 2.05
Li Zhi-Bo,He Kai,Zhang Guo-Hua,Chou Kuo-Chih
The present study utilized W nanopowders (prepared by a two-stage reduction process consisting of steps of carbothermic pre-reduction and hydrogen deep reduction) to produce fine-grained 90W-7Ni-3Fe and 93W-4.9Ni-2.1Fe alloys. The effects of sintering temperature [in a range of 1573 K to 1723 K (1300 °C to 1450 °C)] and time on the microstructure and mechanical properties of W-Ni-Fe alloys were studied in detail. The microstructures of the prepared alloys at 1573 K and 1673 K (1300 °C and 1400 °C) indicated that the grain sizes of W grains are < 5 μ m. However, the grain size dramatically increases to > 5 μ m after sintering for > 60 minutes at 1723 K (1450 °C). The observation shows the as-sintered alloys with different holding times exhibit different fracture modes. With increasing holding time, the hardness of two alloys first increases and then decreases at the same sintering temperature. It is also concluded that the bending strength of alloys increases with the increase of sintering temperature. The maximum hardness of 381 and 393.6 HV was obtained after sintering at 1573 K (1300 °C) for 60 minutes for 90W-7Ni-3Fe and 93W-4.9Ni-2.1Fe alloys, respectively, while the highest bending strength of 1381.4 and 1278.8 MPa could be achieved at 1673 K (1400 °C) for 120 minutes. The excellent mechanical properties of W-Ni-Fe alloys could be attributed to the grain refinement strengthening.
研究领域:
材料科学
·
冶金工程
✓ 已验证
DOI
高影响因子
Journal of Central South University
·
2024
·Vol. 31
·期 5
·1494-1506
·
IF 3.7
Xue Yu-xiao,Zhu De-qing,Pan Jian,You Zhi-xiong,Lyu Xue-wei
In this paper, sinter samples of limonitic nickel laterite were adopted for Fe-Cr-Ni alloy preparation at lower costs. Based on the thermodynamics analysis, smelting characteristics of sinter samples of S1 (4.84 wt% Cr 2 O 3 ) and S3 (7.72 wt% Cr 2 O 3 ) were revealed by the optimization of smelting process parameters. When smelting durations were kept at 60 min and 90 min for S1 and S3 and smelting temperature, coke dosage and slag basicity were maintained at 1600 °C, 20 wt% and 1.0, respectively, the qualified Fe-Cr-Ni alloys containing 84%–88 wt% Fe, 5.6%–9.3 wt% Cr and 1.55%–1.70 wt% Ni were prepared with the recovery rates of Fe, Cr and Ni of over 96%, 90% and 98%, respectively. Higher Cr 2 O 3 content of sinter leads to the prolongation of smelting duration, which is adverse to the reduction of coke ratio and the increase of stainless steel output. The comprehensive furnace burdens including Ni-bearing sinter and Cr-bearing pellets will be developed in the follow-up study for the more efficient preparation of high-Cr ferronickel.
研究领域:
冶金工程
·
材料科学
✓ 已验证
DOI
高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2024
·Vol. 31
·期 17
·25273-25286
·
IF 0
Chen Junxia,Yang Zhenzhen,Li Weigang,Yang Yuying,Zhu Feng,Huo Zongli,Zhou Qing
The poor conductivity, poor stability, and agglomeration of iron-based metal organic framework MIL-88A(Fe) limit its application as persulfate (PS) activator in water purification. Herein, MXene-supported MIL-88A(Fe) composites (M88A/MX) were synthesized to enhance its adsorption and catalytic capability for tetracycline (TC) removal. Scanning electron microscope (SEM), X-ray diffractometer (XRD), Fourier transform infrared spectrometer (FT-IR), and X-ray photoelectron spectroscopy (XPS) were used to characterize prepared materials, confirming the successful attachment of MIL-88A(Fe) to the surface of MXene. M88A/MX-0.2 composites, prepared with 0.2 g MXene addition, exhibit optimal degradation efficiency, reaching 98% under conditions of 0.2 g/L M88A/MX-0.2, 1.0 mM PS, 20 ppm TC, and pH 5. The degradation rate constants of M88A/MX-0.2 were 0.03217 min −1 , which was much higher than that of MIL-88A(Fe) (0.00159 min −1 ) and MXene (0.00626 min −1 ). The removal effects of reaction parameters, such as dosage of M88A/MX-0.2 and PS; initial solution pH; and the presence of the common co-existing constituents (humic acid and the inorganic anions) were investigated in detail. Additionally, the reuse of M88A/MX-0.2 showed that the composites had good cycling stability by recurrent experiments. The results of electron paramagnetic resonance (EPR) and quenching experiments indicated that ·OH, ·SO 4 − , and ·O 2 − were involved in the M88A/MX-0.2/PS system where persulfate oxidation process was activated with prepared M88A/MX-0.2. In addition, the intermediates of photocatalytic degradation were determined by HPLC–MS, and the possible degradation pathways of the target molecules were inferred. This study offered a new avenue for sulfate-based degradation of Fe-based metal organic framework.
研究领域:
环境科学
·
材料科学
✓ 已验证
DOI
PubMed
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2024
·
IF 4.9
Shuyu Chen,Zhengkai Wu,Xueying Cheng,Lu Chen,Yunning Chen,Yingna Guo,Changhua Wang,Qingkun Shang
In this work, we used a simple hydrothermal method to in-situ grow Zn 3 In 2 S 6 on MIL-100(Fe) octahedra, and obtained a MIL-100(Fe)@Zn 3 In 2 S 6 Z-scheme heterojunction photocatalyst. We systematically studied its performance in degrading phenol and p-nitrophenol (PNP) under visible light. MIL-ZIS 6 -2 can remove 89.1 % of phenol within 120 min and nearly 100 % of PNP within 60 min. Its photocatalytic activity to the degradation of phenol is 30.7 times and 1.7 times higher than that of MIL-100(Fe) and Zn 3 In 2 S 6 , respectively. And the photocatalytic activity to degrade PNP is 18.2 times and 1.4 times higher than MIL-100(Fe) and Zn 3 In 2 S 6 . Further research was conducted on its band structure and photocatalytic response mechanism through photoelectric performance, ultraviolet photo-electron spectroscopy, and electron spin resonance spectrometer testing. The results showed that the formation of Z-scheme heterojunction not only increased the specific surface area of the composite photocatalyst, enabling it to provide more reaction sites, but also effectively suppressed the recombination of photogenerated holes and electrons, improving the redox ability of the photocatalyst. This work provides a new perspective for constructing efficient Zn 3 In 2 S 6 -based composite photocatalysts and addressing environmental issues.
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
Catalysts
·
2024
·Vol. 14
·期 8
·528
·
IF 3.8
Dongsheng Xiang,Zhihao Wang,Jingwen Xu,Hongdan Shen,Xiaodong Zhang,Ning Liu
Photocatalysts, such as TiO2, are widely used in photoreduction. However, drawbacks like their wide band gap and short carrier lifetime lead to lower efficiencies with their use. Introducing defects and forming heterostructures of TiO2could extend the carrier’s light-harvesting range from UV to visible light and enhance its lifetime. Herein, an electron-beam irradiation-defected TiO2was induced in MIL-88B(Fe). The structure of the material was characterized using XRD, FT-IR, TEM, HRTEM, and XPS techniques. Remarkably, TiO2under 300 kGy electron-beam irradiation performed the best with a series of 0, 100, 300, and 500 kGy irradiation ratios. PL and UV–vis DRS were utilized to measure the material’s optical properties. The introduction of MIL-88B(Fe) expanded the light response range, reduced the optical band gap, and lengthened the carrier lifetime of the defective TiO2composite photocatalysts, resulting in superior TC photoreduction capabilities of 88B5%300, which degraded 97% of tetracycline (10 mg/L) in water after 120 min.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING RESEARCH & DESIGN
·
2022
·
IF 4.119
Jingjing Sun,Shangqing Chen,Junfeng Wang,Yi Nie
The reduce of the silicon concentration to low level (<5 mg·L −1 ) from the reverse osmosis brine wastewater is challenging and desirable for the maintain the membrane life and performance, as well as the wastewater treatment costs. This work focuses on the removal of silicon from the reverse osmosis brine wastewater by adding FeCl 3 into the plant wastewater for simultaneous Fe(OH) 3 formation and silicon adsorption. The effects of pH, FeCl 3 dosing concentration, reaction time, and temperature on the silicon removal ratio were investigated. It was demonstrated that the silicon removal ratio could reach up to 94% and its residual concentration was 3.2 mg·L −1 , which met the require of water quality in the reverse osmosis system. These results showed that Fe(OH) 3 could effectively be formed by adding FeCl 3 and realize the efficient silicon removal from the reverse osmosis brine wastewater, even when chloride ion (Cl - ), sulfate anion ( S O 4 2 - ) and nitrate ion ( N O 3 - ) were present. Moreover, the adsorption thermodynamics, kinetics and isotherms during the process of the adsorption of silicon from the wastewater by Fe(OH) 3 were studied. The calculated adsorption capacity of silicon could reach 612.74 mg·g −1 , which was much larger than those of reported adsorbents. These results showed that the silicon removal process was spontaneously exothermic and mainly controlled by the physical adsorption and the monomolecular layer adsorption. This simple and cost-effective method could be used for the silicon removal from different kinds of Si-containing wastewater.
研究领域:
环境科学
·
废水处理
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2017
·
IF 6.216
Xiang Zhang,Xiaogang Gu,Shuguang Lu,Mark L. Brusseau,Minhui Xu,Xiaori Fu,Zhaofu Qiu,Qian Sui
The enhancement effect of an environmentally friendly reducing agent, ascorbic acid (AA), on trichloroethene (TCE) degradation by Fe(III)-activated calcium peroxide (CP) was evaluated. The addition of AA accelerated the transformation of Fe(III) to Fe(II), and the complexation of Fe(III)/Fe(II) with AA and its products alleviated the precipitation of dissolved iron. These impacts enhanced the generation of reactive oxygen species (ROSs). Investigation of ROSs using chemical probe tests, electron paramagnetic resonance (EPR) tests, and radical scavenger tests strongly confirm large production of hydroxyl radicals (HO ) that is responsible for TCE degradation. The generation of Cl − from the degraded TCE was complete in the enhanced CP/Fe(III)/AA system. The investigation of solution matrix effects showed that the TCE degradation rate decreases with the increase in solution pH, while Cl − , SO 4 2− and NO 3 − anions have minor impact. Conversely, HCO 3 − significantly inhibited TCE degradation due to pH elevation and HO scavenging. The results of experiments performed using actual groundwater indicated that an increase in reagent doses are required for effective TCE removal. In summary, the potential effectiveness of the CP/Fe(III)/AA oxidation system for remediation of TCE contaminated groundwater has been demonstrated. Additional research is needed to develop the system for practical implementation.
研究领域:
环境科学
·
化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMOSPHERE
·
2024
·
IF 8.1
Jingyuan Yue,Xiaojin Hu,Huijun Xie,Zhen Hu,Haiming Wu,Jian Zhang,Bo Sun,Lushan Wang
Bisphenol A (BPA) in seawater tends to be deposited in coastal sediments. However, its degradation under tidal oscillations has not been explored comprehensively. Hydroxyl radicals (·OH) can be generated through Fe cycling under redox oscillations, which have a strong oxidizing capacity. This study focused on the contribution of Fe-mediated production of ·OH in BPA degradation under darkness. The removal of BPA was investigated by reoxygenating six natural coastal sediments, and three redox cycles were applied to prove the sustainability of the process. The importance of low reactivity Fe(II) in the production of ·OH was investigated, specifically, Fe(II) with carbonate and Fe(II) within goethite, hematite and magnetite. The degradation efficiency of BPA during reoxygenation of sediments was 76.78–94.82%, and the contribution of ·OH ranged from 36.74% to 74.51%. The path coefficient of ·OH on BPA degradation reached 0.6985 and the indirect effect of low reactivity Fe(II) on BPA degradation by mediating ·OH production reached 0.5240 obtained via partial least squares path modeling (PLS-PM). This study emphasizes the importance of low reactivity Fe(II) in ·OH production and provides a new perspective for the role of tidal-induced ·OH on the fate of refractory organic pollutants under darkness.
研究领域:
环境科学
·
化学
·
海洋科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2024
·
IF 8.1
Jingjing Tang,Hongchao Li,Xuan Zhang,Jieshu Qian,Bingcai Pan
Fe-based metal–organic frameworks (MOFs) have garnered significant attention as catalysts for heterogeneous Fenton reactions, while the limited efficiency of the Fe(III)/Fe(II) redox cycle hinders their widespread use in wastewater treatment. Herein, we successfully incorporated carbon nanotubes (CNTs) into MIL-101(Fe) to modulate the coordination environment of Fe for achieving better catalytic activity. The MIL-101(Fe)/CNTs/H 2 O 2 system shows outstanding performance in degrading various pollutants, with the catalytic activity of the MIL-101(Fe)/CNTs composites (98.8%) significantly surpassing that of MIL-101(Fe) alone (26.4%) or CNTs alone (3.5%). Multiple experimental findings suggest that this synergistic effect is primarily attributed to the C-O-Fe bridge bonds resulting from the interaction of surface carboxyl groups on CNTs with Fe in MIL-101(Fe). This unique coordination structure accelerates the redox cycle of Fe(III)/Fe(II), thereby promoting the generation of hydroxyl radicals (HO • ). Furthermore, the MIL-101(Fe)/CNTs composites demonstrate excellent reusability and stability, maintaining effectiveness over a wide pH range from 3.0 to 6.5. This study provides new insights into regulating the microstructure of Fe-based MOFs to enhance their Fenton catalytic activity.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）