CERAMICS INTERNATIONAL
·
2020
·
IF 3.83
Yadan Luo,Ying Li,Ning Zhang,Yushi Ding,Hongzheng Li,Gang Chen
The effects of bromine (Br) addition on electrical properties and chemical stability of Gd-doped barium cerate proton-conducting electrolyte were investigated. BaCe 0.8 Gd 0.2 O 2.8±δ Br 0.2 (BCGBr) and BaCe 0.8 Gd 0.2 O 3-α (BCG) powders with CuO as sintering aid were obtained via a solid-state reaction. The results of X-ray fluorescence (XRF) confirm that only trace amounts of Br are present in BCGBr after high temperature sintering at 1600 °C, indicating that Br addition influences stoichiometry but not directly the physicochemical properties. Nevertheless, the XRD results from the treated BCGBr and BCG electrolyte pellets show that the chemical stability of BCGBr in water and/or CO 2 -containing atmospheres is conspicuously improved. The conductivities of electrolyte sintered at 1600 °C for 10 h were investigated in various atmospheres by AC impedance technique. The total conductivity ( σ t o t ) of BCGBr under wet Ar is lower than that of BCG. Partial-conductivities components ((proton ( σ OH O · ), oxygen ion ( σ V O · · ), and hole ( σ h · )) are presented for BCGBr according to the defect structure model. The results show that the proton conductivity of BCGBr remains nearly constant over the 550–750 °C temperature range. Although σ t o t of Br-synthesized sample slightly decreases, the BCGBr exhibits a high σ OH O · (0.058 S cm −1 at 750 °C) under pH 2 O = 0.038 atm and pO 2 = 1 atm. P-type and oxygen ion conduction are dominant in an oxidative atmosphere (pO 2 = 1 atm) at 650 °C. Under low oxygen conditions (pO 2 = 10 −4 atm), BCGBr shows the behavior of mixed conduction (oxygen ions ( V O · · ) and protons ( OH O · )). Besides, the main carriers in BCGBr oxide change from OH O · to V O · · as temperature increased.
研究领域:
材料科学
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固体化学
·
电化学
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产品关联
DOI
高影响因子
TALANTA
·
2024
·
IF 5.6
Yongsheng Zhang,Jian Yuan,Rui Gao,Yang Zhao,Zefu Ye,Zhujun Zhu,Peihua Zhang,Lei Zhang,Wangbao Yin,Suotang Jia
Ash content, as a crucial indicator of coal quality, its rapid and accurate determination is pivotal to improve the energy utilization of coal and reduce environmental pollution. Traditional spectroscopic methods face significant challenges in acquiring accurate information from coal samples due to the notorious matrix effects arising from their complex composition, vast molecular structure, and diverse coal types. In this study, the feasibility of total reflection X-ray fluorescence (TXRF) combined with partial least squares (PLS) for the determination of coal ash was firstly investigated based on the TXRF being unaffected by matrix effects. Firstly, coal samples were prepared as suspensions, and the effects of sample particle size and different dispersants on the results of TXRF analyses were evaluated. The accuracy and applicability of the chosen sample preparation strategies were further validated using inductively coupled plasma mass spectrometry (ICP-MS) and two certified reference materials (CRMs). Subsequently, based on the analysis of 19 coal samples, the impact of three different predictive variables on the performance of the PLS model was investigated: (a) TXRF full spectrum normalized by the net intensity of the internal standard; (b) net intensity of characteristic peaks for 12 elements (Al, Si, K, Ca, Ti, Fe, Cr, Mn, Cu, Ni, and Sr) normalized by the net intensity of the internal standard; (c) concentrations of the aforementioned 12 elements. The results demonstrate that the PLS model constructed usingthe TXRF full spectrum normalized by the net intensity of the internal standard exhibits the best predictive capabilities, with the determination coefficient of calibration set (R 2 ) and mean square error (MSE) of the prediction set reaching 0.9736 and 0.99 %, respectively. Moreover, the measurement accuracy of this model was six times greater than that obtained with traditional X-ray fluorescence (XRF). Presented analytical results display the possibilities of combining TXRF with PLS for coal quality evaluation.
研究领域:
分析化学
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环境科学
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能源资源
✓ 已验证
产品关联
DOI
PubMed
高影响因子
MOLECULES
·
2025
·Vol. 30
·期 15
·3076
·
IF 4.6
Shuai Zhu,Junru Chen,Yun Zhu,Baoke Zhang,Jing Jia,Meng Pan,Zhipeng Yang,Jianhua Cao,Yating Shen
Chromium slag sites pose severe environmental risks due to hexavalent chromium (Cr(VI)) contamination, characterized by high mobility and toxicity. This study focused on chromium-contaminated soil from a historical chromium slag site in North China, where long-term accumulation of chromate production residues has led to serious Cr(VI) pollution, with Cr(VI) accounting for 13–22% of total chromium and far exceeding national soil risk control standards. To elucidate Cr(VI) transformation mechanisms and elemental linkages, a combined approach of macro-scale condition experiments and micro-scale analysis was employed. Results showed that acidic conditions (pH < 7) significantly enhanced Cr(VI) reduction efficiency by promoting the conversion of CrO42−to HCrO4−/Cr2O72−. Among reducing agents, FeSO4exhibited the strongest effect (reduction efficiency >30%), followed by citric acid and fulvic acid. Temperature variations (−20 °C to 30 °C) had minimal impact on Cr(VI) transformation in the 45-day experiment, while soil moisture (20–25%) indirectly facilitated Cr(VI) reduction by enhancing the reduction of agent diffusion and microbial activity, though its effect was weaker than chemical interventions. Soil grain-size composition influenced Cr(VI) distribution unevenly: larger particles (>0.2 mm) in BC-35 and BC-36-4 acted as main Cr(VI) reservoirs due to accumulated Fe-Mn oxides, whereas BC-36-3 showed increased Cr(VI) in smaller particles (<0.074 mm). μ-XRF and correlation analysis revealed strong positive correlations between Cr and Ca, Fe, Mn, Ni (Pearson coefficient > 0.7,p< 0.01), attributed to adsorption–reduction coupling on iron-manganese oxide surfaces. In contrast, Cr showed weak correlations with Mg, Al, Si, and K. This study clarifies the complex factors governing Cr(VI) behavior in chromium slag soils, providing a scientific basis for remediation strategies such as pH adjustment (4–6) combined with FeSO4addition to enhance Cr(VI) reduction efficiency.
研究领域:
环境科学
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土壤化学
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污染控制
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地球化学
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环境修复
✓ 已验证
产品关联
DOI
PubMed
高影响因子
INORGANIC CHEMISTRY COMMUNICATIONS
·
2021
·
IF 2.495
Dianchun Ju,Haiwei Yao,Han Ma,Rui Mao,Jiayong Qiu,Chunyu Chen
To deal with the removal of PbO 2 during the purification process of the Zn-containing rotary hearth furnace (RHF) dust, this study adopts a choline chloride-urea (ChCl-urea) based deep eutectic solvent system and water-washed Zn-containing RHF dust as the main target of investigations, preparing ZnO nanoparticles using a Zn-induced PbO 2 removal and thermal treatment of the precursor. The effects of the mass ratio of Zn particles and Zn dust (maked as Zn particles - Zn dust), reaction temperature, and reaction time on the removal of PbO 2 were also investigated. The ZnO nanoparticles and the PbO 2 -removed products were characterized by X-ray diffractometry, X-ray fluorescence spectroscopy, scanning and transmission electron microscopy. The results showed that the optimal conditions for efficient removal of PbO 2 included the reaction temperature of 80 °C, The Zn particles - Zn dust is 1.6, with a reaction time of 3 h. The final product had a ZnO content of 98.332% with a particle size distribution in the range of 10–100 nm with an average diameter of 39 nm, belonging to the Category-II ZnO nanoparticles. The PbO 2 removal mechanism mainly involved the dissolving of PbO 2 in ChCl-urea, forming [Pb(ClO·urea) 2 ] 2− , and the replacement reaction between Zn particles and [Pb(ClO·urea) 2 ] 2− , producing metallic Pb and [ZnClO·urea] − .
研究领域:
环境科学
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材料科学
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2022
·Vol. 57
·期 2
·1302-1313
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IF 4.682
He Fupo,Qiu Chao,Wang Yao,Lu Teliang,Ye Jiandong
The aim of this study was to fabricate silicon/gallium co-substituted tricalcium phosphate bioceramics having the ability to promote osteoblast activities as well as hinder osteoclast activities. The silicon/gallium co-substituted tricalcium phosphates were synthesized with a solid-state reaction route, and their bioceramics were prepared by the process of molding and sintering. The bioceramics were characterized employing X-ray fluorescence spectroscopy, X-ray diffraction and scanning electron microscopy. Porosity and compressive strength tests, and experiments for in vitro cell response evaluation were performed. The results manifested that silicon/gallium co-substitution promoted transition of β-tricalcium phosphate to α-tricalcium phosphate and additionally gave rise to new phases of silicocarnotite and Ca 2 SiO 4 . In contrast to a single gallium substitution, the silicon/gallium co-substitution retarded the densification process but retained the high mechanical strength of bioceramics, and maintained the inhibitory effect of gallium on the osteoclast activities. The tricalcium phosphate bioceramics with substitutions of 2.5 mol% gallium and 10 mol% silicon possessed considerable mechanical strength, enhanced osteoblast activities and restrained osteoclast activities, so they were expected to efficiently reconstruct the bone defects in the environment of osteoporosis.
研究领域:
生物材料
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生物医学工程
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材料科学
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细胞生物学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2023
·
IF 6.7
Xudong Gong,Qiang Tian,Jiebiao Li,Ju Wang,Minhao Yan,Mark J. Henderson
Incorporation of fission products in spent nuclear fuel is of interest in the frame of safe storage of high-level nuclear waste in a deep geological repository. Uranyl oxyhydroxide films were grown on silicon wafer to represent the corrosion product formed on the surfaces of the fuel. Films were obtained by hydrolysis of uranyl ions (9 mM) in mild conditions (≤60 °C) using either Mg(OH) 2 , raw brucite, La(OH) 3 , or NH 4 OH to control the solution pH to ≈ 5.0. To identify the mineral phases we used the grazing-incidence X-ray technique. Atomic force microscopy data indicated that the surfaces of metaschoepite films prepared using either Mg(OH) 2 or brucite at 50 °C for 3 h were self-affine fractal ( D f = 2.5). The concentration (wt.%) of reactant ions detected in a metaschoepite film after reaction at 70 °C for three days as determined by X-ray fluorescence was: La (8.90) > Nd (5.6) > Ce (3.2) > Eu (2.5) > Pb (0.7) > Sr (0.14). Metaschoepite and sodium uranate hydrate were identified in a film formed in Cl-SO 4 -Na type groundwater from the Beishan area (China), the preselected area of a radioactive waste disposal repository.
研究领域:
核废料管理
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材料科学
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2017
·Vol. 7
·期 38
·23272-23278
·
IF 3.108
Peicheng Wang,Yang Zhao,Hongbin Zhang,Tao Yu,Yahong Zhang,Yi Tang
A series of diquaternary pyrazolium-derived organic templates (N,N′-dimethyl-N,N′-1,6-dihexylidenedipyrazolium, N,N′-diethyl-N,N′-1,6-dihexylidenedipyrazolium, N,N′-dipropyl-N,N′-1,6-dihexylidenedipyrazolium, denoted as 6C-DMP, 6C-DEP, 6C-DPP, respectively) with methyl, ethyl and propyl groups substituted on the N atom of pyrazole ring at both terminals have been used in the synthesis of high silica MTW and MFI zeolites. Through combining the characterization results, including XRD, NMR, elemental analysis, TG, XRF, FE-SEM, N2 sorption and FE-TEM, with molecular mechanics simulations to explore the location, orientation and the interaction energies of the three templates, we confirmed the state of templates in zeolite framework, carefully characterized their morphology/structure properties, and finally investigated their different spatial effects for the zeolite formation. The study found that 6C-DMP and 6C-DEP are able to produce MTW, while 6C-DPP is able to produce MFI. 6C-DMP, owing to a good match with the MTW framework and can be used to synthesize regular MTW zeolite with few defects. The MTW zeolite prepared by using 6C-DEP as a template presents more defects and irregular macromorphology due to a relatively poor match to the MTW framework. 6C-DPP can get MFI other than MTW due to a larger spatial hindrance, and it is located in the MFI framework with a special spatial orientation.
研究领域:
化学
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材料科学
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物理化学
✓ 已验证
产品关联
DOI
高影响因子
ENERGY CONVERSION AND MANAGEMENT
·
2018
·
IF 6.377
Junguang Meng,Zengli Zhao,Xiaobo Wang,Anqing Zheng,Dongyan Zhang,Zhen Huang,Kun Zhao,Guoqiang Wei,Haibin Li
Ni/Fe bimetallic catalysts were synthesized on an olivine support using the wetness impregnation (WI) and thermal fusion (TF) methods, and catalytic cracking and steam reforming on different tar model compounds (phenol and naphthalene) were investigated in a fixed bed reactor. The effects of the reaction temperature and space-time on the catalytic cracking activity of phenol and naphthalene were tested, and the influences of steam on the carbon molar ratio (S/C) and different synthesized methods on the steam reforming of phenol and naphthalene were also studied. In addition, the carbon deposited on the catalyst was analysed using temperature program oxidation (TPO), Raman spectroscopy and transmission electron microscopy (TEM) methods. The elemental composition of the catalyst was analysed by X-ray fluorescence (XRF), and the physiochemical properties of the catalysts were characterized via X-ray diffraction (XRD), the BET surface area, scanning electron microscopy (SEM), TEM, Raman spectroscopy, temperature program reduction (TPR), and X-ray photoelectron spectroscopy (XPS). The results showed that the structure of TF-Ni/Fe/olivine changed considerably compared with that of calcined olivine (mainly the Mg 2 SiO 4 phase) and that a portion of Fe was fused into the olivine structure and reorganized into a new (Mg, Fe) Fe 2 O 4 phase. After reduction, the Ni-Fe alloy was detected on both catalysts, and the particle size of the Ni-Fe alloy on TF-Ni/Fe/olivine was smaller than that of WI-Ni/Fe/olivine. The TF-Ni/Fe/olivine cracked phenol into small-molecule gas (CO and H 2 ) and a small quantity of olefin. By contrast, phenol was polymerized to naphthalene in the absence of a catalyst. The phenol and naphthalene steam reforming conversion on WI-Ni/Fe/olivine were both higher than that of TF-Ni/Fe/olivine. A 100-h stability test of phenol steam reforming on TF-Ni/Fe/olivine and WI-Ni/Fe/olivine was conducted, and TF-Ni/Fe/olivine showed higher stability in the early stages of the experiment due to stronger interactions between the active sites and olivine support. The deposited carbon from naphthalene steam reforming was more difficult to eliminate because it contained more C β and C γ , which had higher degrees of graphitization.
研究领域:
催化
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化学工程
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材料科学
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
CHINESE CHEMICAL LETTERS
·
2019
·
IF 3.839
Xu Guan,Yan Wang,Wangfeng Cai
A copper-centred metal-organic framework material MOF-101 with 2-bromine terephthalic acid as ligands was synthesized by solvothermal method at 70 °C and modified by loading Ag + to improve the selective adsorption performance. The MOF-101 and Ag + /MOF-101 prepared were characterised by powder X-ray diffraction, X-ray fluorescence, Fourier transform infrared spectroscopy, scanning electron microscopy, and thermogravimetric analysis. The adsorptive desulphurisation was quantified by adsorbing dibenzothiophene (DBT) from model oils. The loading of Ag + enhanced the deep adsorptive desulfurization capacity for DBT and significantly weaken the adsorption competitiveness of toluene. As a result, the DBT concentration of model oil was reduced from 50 ppm S to 10.2 ppm S . Possible understandings were put forward to explain the adsorption performance of Ag + /MOF-101. The kinetics and isotherm data can be well-described by the pseudo -second-order kinetic model and the Langmuir model.
研究领域:
化学
·
材料科学
·
环境科学
✓ 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）