International Journal of Extreme Manufacturing
·
2024
·Vol. 6
·期 5
·055002
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IF 16.1
Lurun Xu,Jingchao Tao,Zhuguo Li,Guo He,Dongshi Zhang
Exsolution, as an effective approach to constructing particle-decorated interfaces, is still challenging to yield interfacial films rather than isolated particles. Inspired by in vivo near-infrared laser photothermal therapy, using 3 mol% Y2O3 stabilized tetragonal zirconia polycrystals (3Y-TZP) as host oxide matrix and iron-oxide (Fe3O4/γ-Fe2O3/α-Fe2O3) materials as photothermal modulator and exsolution resource, femtosecond laser ultrafast exsolution approach is presented enabling to conquer this challenge. The key is to trigger photothermal annealing behavior via femtosecond laser ablation to initialize phase transition from monoclinic zirconia (m-ZrO2) to tetragonal zirconia (t-ZrO2) and induce t-ZrO2 columnar crystal growth. Fe-ions rapidly segregate along grain boundaries and diffuse towards the outmost surface, and become 'frozen', highlighting the potential to use photothermal materials and ultrafast heating/quenching behaviors of femtosecond laser ablation for interfacial exsolution. Triggering interfacial iron-oxide coloring exsolution is composition and concentration dependent. Photothermal materials themselves and corresponding photothermal transition capacity play a crucial role, initializing at 2 wt%, 3 wt%, and 5 wt% for Fe3O4/γ-Fe2O3/α-Fe2O3 doped 3Y-TZP samples. Due to different photothermal effects, exsolution states of ablated 5 wt% Fe3O4/γ-Fe2O3/α-Fe2O3-doped 3Y-TZP samples are totally different, with whole coverage, exhaustion (ablated away) and partial exsolution (rich in the grain boundaries in subsurface), respectively. Femtosecond laser ultrafast photothermal exsolution is uniquely featured by up to now the deepest microscale (10 μm from 5 wt%-Fe3O4-3Y-TZP sample) Fe-elemental deficient layer for exsolution and the whole coverage of exsolved materials rather than the formation of isolated exsolved particles by other methods. It is believed that this novel exsolution method may pave a good way to modulate interfacial properties for extensive applications in the fields of biology, optics/photonics, energy, catalysis, environment, etc.
研究领域:
材料科学
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光学
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生物医学工程
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产品关联
DOI
高影响因子
ACS Catalysis
·
2016
·
IF 9.307
Xianwei Wang,Nobutaka Maeda,Alfons Baiker
Promotion of Au/TiO2 by FeOx addition is shown to result in a very strong enhancement of activity and selectivity in the NO reduction with CO. The nanocomposite Au-FeOx/TiO2 catalysts were prepared by deposition–precipitation (Au/TiO2) and subsequent impregnation (FeOx). Structural characterization of the nanocomposite catalysts using XRD, TEM, TPR, XPS, and DRIFTS revealed that they consist of titania-supported Au particles of about 4.4–4.8 nm size, which were partially covered with a thin layer of FeOx,, mainly made up of Fe2+ (FeO), in addition to a small fraction of Fe3+ (Fe2O3). In situ DRIFTS studies showed that, in comparison to Au/TiO2, on the Au-FeOx/TiO2 nanocomposites new adsorption sites were created, which led to enrichment of CO and NO molecules on the Au surface and at its interfaces with FeOx and TiO2. At the reaction temperature (250 °C), a new surface NO–CO complex, where both Fe and Au are proposed to be involved in the adsorptive interaction, was discovered. The titania-supported Au-FeOx nanocomposites considerably facilitated the formation of this complex and contributed to the striking enhancement of the catalytic performance (activity and selectivity) of the Au-based catalyst.
研究领域:
催化化学
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材料科学
✓ 已验证
DOI
高影响因子
Frontiers of Environmental Science & Engineering
·
2017
·Vol. 12
·期 1
·1-7
·
IF 1.716
Shi Jin,Zhang Zihao,Chen Mingxia,Zhang Zhixiang,Shangguan Wenfeng,Gu Shunchao,Shin-ichi Hirano
Fe-BEA catalysts are active for the NH3-SCR of NO. For industrial application, a binder should be added to the Fe-BEA catalysts to make them tightly adhere to the monoliths. The addition of alumina and zirconia as binders to the Fe-BEA led to a different effect on NO conversion. The catalytic activity of the mixed samples was evaluated by the temperature programmed procedure in a flow-reactor system, and the mechanism was analyzed via SEM, BET, XRD and XPS. It was found that larger iron particles were formed by the migration of parent iron particles in the Fe-BEA catalyst with alumina. This led to the increase of Fe 3+ magnitude and iron cluster, enhancing the abilities of NO oxidation and storage. Accordingly, the SCR activity increased slightly in low temperature but decreased sharply in high temperature. For the Fe-BEA with zirconia sample, NO oxidation and storage abilities decreased due to the less iron clusters. The increase of Fe 3+ magnitude resulted in higher catalytic oxidation ability, which gave rise to little change in the SCR activity compared with the Fe-BEA.
研究领域:
催化
·
环境科学
✓ 已验证
DOI
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
·
2021
·
IF 7.963
Yan Li,Liangmin Gao,Yu Wang,Shuo Cheng,Guowei Wu,Xuan Yang,Shunli Wan
Biochar-supported metallic oxides are attractive adsorbents for heavy metal cleanup, but the adsorption performance is still unsatisfactory as a result of the self-aggregation of the incorporated metallic oxides. A new hybrid nano-material was prepared through impregnating hydrated ferric oxide (HFO) nanoparticles within biochar bearing high-density charged oxygen-containing groups (e.g., carboxyl and hydroxyl groups) (ABC) derived from HNO 3 treatment. The as-made adsorbent, denoted as HFO-ABC, possesses highly dispersed HFO nanoparticles with typical size lower than 20 nm, and exhibits greater sorption capacity for Cd(II) and Cu(II) than the pristine biochar-supported HFO. It also shows great sorption preference toward Cd(II) and Cu(II) in co-presence of high levels of Ca 2+ , Mg 2+ and humic acid (HA). Such prominent performance is put down to the high-density charged functional groups on the host ABC, which not only promote the dispersion of the immobilized HFO nanoparticles but also generate the potential Donnan membrane effect, i.e., the pre-concentration and permeation of target metals prior to their preferable adsorption by nano-HFO. The predicted effective coefficients of intra-particle diffusion for Cu(II) and Cd(II) are 3.83 × 10 −9 and 4.33 × 10 −9 cm 2 /s, respectively. HFO-ABC exhibits excellent performance for fixed-bed column application, and yields 513 and 990 BV effluents for Cd(II) and Cu(II) to achieve their discharge standards, respectively. The spent HFO-ABC could be in situ regenerated using binary HCl-CaCl 2 solution with desorption efficiency higher than 95%. All results manifest that increasing charged functional groups via HNO 3 treatment is an effective measure for boosting sorption performance of biochar-based nanocomposites.
研究领域:
环境科学
·
材料科学
✓ 已验证
DOI
PubMed
高影响因子
ENVIRONMENTAL SCIENCE & TECHNOLOGY
·
2024
·
IF 10.8
Wanli Lian,Guanghui Yu,Jie Ma,Juan Xiong,Cuiyun Niu,Ran Zhang,Haijiao Xie,Liping Weng
Despite extensive study, geochemical modeling often fails to accurately predict lead (Pb) immobilization in environmental samples. This study employs the Charge Distribution MUlti-SIte Complexation (CD-MUSIC) model, X-ray absorption fine structure (XAFS), and density functional theory (DFT) to investigate mechanisms of phosphate (PO4) induced Pb immobilization on metal (hydr)oxides. The results reveal that PO4 mainly enhances bidentate-adsorbed Pb on goethite via electrostatic synergy at low PO4 concentrations. At relatively low pH (below 5.5) and elevated PO4 concentrations, the formation of the monodentate-O-sharing Pb-PO4 ternary structure on goethite becomes important. Precipitation of hydropyromorphite (Pb5(PO4)3OH) occurs at high pH and high concentrations of Pb and PO4, with an optimized log Ksp value of −82.02. The adjustment of log Ksp compared to that in the bulk solution allows for quantification of the overall Pb-PO4 precipitation enhanced by goethite. The CD-MUSIC model parameters for both the bidentate Pb complex and the monodentate-O-sharing Pb-PO4 ternary complex were optimized. The modeling results and parameters are further validated and specified with XAFS analysis and DFT calculations. This study provides quantitative molecular-level insights into the contributions of electrostatic enhancement, ternary complexation, and precipitation to phosphate-induced Pb immobilization on oxides, which will be helpful in resolving controversies regarding Pb distribution in environmental samples.
研究领域:
环境科学
·
地球化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
FUEL
·
2018
·
IF 4.908
Yu Chen,Xin Guo,Fan Wu,Yu Huang,Zhanchi Yin
Hematite (α-Fe 2 O 3 ) has been proved to be a promising sorbent for mercury removal in various situations. The mercury removal performance of α-Fe 2 O 3 was investigated using a simulated coal gasification syngas containing Hg 0 , N 2 , HCl, and/or H 2 S, a series of experiments were designed with HCl and H 2 S separately and both employed. For a better understanding in the interaction between HCl and H 2 S in mercury removal, the differences in mercury oxidation were demonstrated on the basis of density functional theory calculations. The rate-limiting step in HgCl 2 formation is Hg 0 → HgCl with the energy barrier of 139.47 kJ/mol, but for H 2 S in mercury oxidation, the generation of active sulfur species is the key step and the rate-limiting step is detachment of second H with an energy barrier of 57.53 kJ/mol. Experimental results point that HCl has inhibition on H 2 S for mercury removal, it may be ascribed to the competition of active Fe sites on Fe 2 O 3 . Conversely, HCl contributes to the mercury oxidation at high temperature while H 2 S has a limit effect at elevated temperature.
研究领域:
环境科学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Energy Chemistry
·
2016
·
IF 2.322
Ran An,Guizhuan Xu,Chun Chang,Jing Bai,Shuqi Fang
Butyl levulinate (BL) is a promising new candidate as diesel fuel and fuel additive. In this study, an efficient process for a one-pot synthesis of BL from biomass-derived carbohydrates in butanol medium with the catalysis of metal sulfates was developed. The catalytic activity of a series of metal sulfates for the synthesis of BL from fructose was investigated. Among various metal sulfates, ferric sulfate Fe 2 (SO 4 ) 3 was found to be the most efficient catalyst, which gave a remarkably high BL yield of 62.8 mol% under the conditions of 463 K, 3 h, a catalyst dosage of 5.0 g/L, and fructose concentration of 25 g/L. Different carbohydrates including glucose, cellulose , inulin and sucrose were also used for one-pot synthesis of BL with the catalysis of Fe 2 (SO 4 ) 3 , showing the yields of 39.6, 30.5, 56.6 and 50.1 mol%, respectively. In addition, the recycling and reuse of Fe 2 (SO 4 ) 3 was studied by characterizing them using powder X-ray diffraction (XRD), scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS). A plausible reaction pathway for the one-pot synthesis of BL from fructose was proposed. This study provides a facile and feasible way for the synthesis of BL from biomass.
研究领域:
生物化学
·
能源科学
✓ 已验证
产品关联
DOI
高影响因子
Polymers
·
2022
·Vol. 14
·期 17
·3584
·
IF 4.967
Mingpan Zhang,Fuli Wang,Xinran Shi,Jing Wei,Weixia Yan,Yihang Dong,Huiqiang Hu,Kai Wei
In this study, an iron oxide/carbon nanofibers (Fe2O3/CNFs) composite was prepared by a combination of electrospinning and hydrothermal methods. The characterization of Fe2O3/CNFs was achieved via scanning electron microscopy (SEM), infrared spectroscopy (IR), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). It is shown that when the hydrothermal reaction time was 180 °C and the reaction time was 1 h, the Fe2O3nanoparticle size was about 90 nm with uniform distribution. The photodegradation performance applied to decolorize methyl orange (MO) was investigated by forming a heterogeneous Fenton catalytic system with hydrogen peroxide. The reaction conditions for the degradation of MO were optimized with the decolorization rate up to more than 99% within 1 h, which can decompose the dyes in water effectively. The degradation process of MO by Fenton oxidation was analyzed by a UV-visible NIR spectrophotometer, and the reaction mechanism was speculated as well.Keywords:Fe2O3;carbon nanofibers;heterogeneous Fenton;methyl orange (MO)
研究领域:
材料科学
·
环境科学
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产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
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2022
·
IF 16.744
Jiahui Zhou,Xuesong Li,Jia Yuan,Zhiwei Wang
Iron-mediated activation of peroxymonosulfate (PMS) has long been of a great interest for the effective oxidation of micropollutants. In this study, ferroferric oxide doped powdered activated charcoal (PAC) was prepared by a chemical co-precipitation method in which abundant ferroferric oxide nanocatalyst (FONC) were immobilized on the PAC. The catalyst (FONC@PAC) enabled an efficient degradation of tetracycline via activation of PMS over a wide range of pH and the removal efficiency could reach up to 86.9%. It was verified that the surface-bound SO 4 •− and 1 O 2 were the predominant reactive oxygen species in the catalytic process. A possible degradation pathway of TC was deduced and the toxicity of treated wastewater was drastically reduced after the catalytic degradation. Meanwhile, the catalyst demonstrated a decent degradation performance even after four recycles and suffered from little iron loss. The novel catalyst demonstrated its great potential for the removal of antibiotics in the wastewater.
研究领域:
环境科学
·
化学工程
✓ 已验证
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2019
·
IF 5.383
Shuang Gao,Dan Wang,Yinglin Wang,Chuang Li,Yichun Liu,Norihiro Suzuki,Chiaki Terashima,Akira Fujishima,Xintong Zhang
Doping with tetravalent titanium cation impurities is an effective means to enhance the performance of hematite (α-Fe 2 O 3 ) photoanodes. These nevertheless face problems of inefficient activation of impurity donors, which thereby impairs the photoelectrochemical water oxidation property of hematite. Herein, we propose a simple method to activate Ti 4+ dopants in spray-pyrolyzed hematite thin films via a rapid thermal annealing (RTA) treatment. The donor carrier density of Ti-doped Fe 2 O 3 thin films (doping level, i.e., Ti/Fe: 0.5–10%) is significantly increased by RTA at 700 °C for 30 s, for instance, ca. 1.35 × 10 19 cm −3 at the doping level of 5% (5%-Ti:Fe 2 O 3 -700). This is 19.3 times as high as those treated by traditional annealing in a muffle furnace at 500 °C for 1800 s (5%-Ti:Fe 2 O 3 -500). A photocurrent density of 5%-Ti:Fe 2 O 3 -700 for water oxidation reaches 0.91 mA cm −2 at 1.23 V vs. RHE. This is ca. 6-fold higher than 5%-Ti:Fe 2 O 3 -500. Electrochemical impedance spectroscopy , XRD, Raman spectroscopy, and scanning probe microscopy measurements suggest that RTA performs more efficiently than traditional annealing for promoting the substitutional incorporation of Ti 4+ cations into the hematite lattice. This simple RTA treatment for donor-activation should be applicable to other semiconductor-dopant combinations—thin films or nanostructures , for the development of high-performance photoanodes for water oxidation.
研究领域:
材料科学
·
电化学
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产品关联
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2022
·
IF 9.965
Tong Wang,Lili Gao,Peng Wang,Xuefeng Long,Huan Chai,Feng Li,Jun Jin
Aiming at the drawbacks of hematite like poor conductivity and tardy oxidation kinetics, herein, we utilized dual dopants in the bulk and surface to ameliorate the situation. Specifically, doping optimal amount of Zr 4+ in the hematite (Zr:Fe 2 O 3 ) enhances the conductivity of hematite due to the higher charge carrier density. Further, F:FeOOH could form p-n heterojunction in bulk where a potential barrier is built up that repels electrons but prompts holes transferring to F:FeOOH for water oxidation. What’s more, the high electronegative of F - would withdraw electron from the Fe site in FeOOH, and the enhanced positive electricity of Fe 3+ is beneficial for adsorption of OH – as well as enhance the conductivity of FeOOH to expedite holes transfer. As a result, the composite photoanode (F:FeOOH/Zr:Fe 2 O 3 ) shows a 3.25-times enhanced photocurrent density comparing with α-Fe 2 O 3 . The special designation employs ultrathin F:FeOOH to act as both p-type semiconductor and efficient co-catalyst, avoiding redundant layer that would extend the migration distance of holes. On the top of that, the dual modification approach provides an extensive prospect for the further application of hematite.
研究领域:
材料科学
·
能源科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
MATERIALS RESEARCH BULLETIN
·
2021
·
IF 4.641
Xinshan Rong,Shixian Zhang,Jian Rong,Jing Wei,Xuchun Qiu,Zhiren Wu
Z-scheme nitrogen-deficient graphitic carbon nitride/ferric oxide (GCN x /FO) photocatalysts were obtained by a one-step calcination method. The number of nitrogen defects was tuned by the application of KOH, while the ferric oxide phase and magnetism was controlled by the usage of ferrous oxalate. Interconversion between the hematite (α) and maghemite (γ) phases of Fe 2 O 3 was analyzed by X-ray diffraction, and magnetism of the GCN x -0.1/FO products provided via vibrating sample magnetometer test. The introduction of nitrogen defects narrowed the bandgap and extended the spectral range of light absorption while improving the ability to capture and activate N 2 effectively. Surface defects were employed as active sites, and the ammonia generation concentration reached approximately 69.7 μmol/L/h by N 2 photofixation under visible light. Due to their ease of synthesis and tuning, high photocatalytic activity, convenient and rapid collection for reuse, and excellent stability, GCN x /FO composited photocatalysts possess vast potential for use in clean ammonia production.
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