COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2019
·
IF 3.131
Zhanglei Zhu,Wanzhong Yin,Bin Yang,Yafeng Fu,Jiwei Xue
Slime contamination is an urgent problem that should be solved in coal flotation. The adverse effects of slime contamination, by which low-ash clean coal is covered by high-ash fine slime and hence cannot be separated through the direct flotation process, have been recognized for the past decades. In this investigation, to reduce slime contamination, the reverse-and-direct flotation process was proposed. Flotation results indicated that, based on the similar ash content, the concentrate yield increased by 7.36% using the reserve-and-direct flotation process compared with the two-steps direct flotation process. XPS (X-ray Photoelectron Spectroscopy) and SEM (Scanning Electron Microscopy) results verified that the reduction of fine clay minerals coating on the surface of clean coal was achieved and hence the flotation performance was improved with the reverse-and direct flotation process. Therefore, it can be arrived that the reverse-and-direct flotation process is a potential and effective separation method to upgrade the flotation performance of fine coking coal.
研究领域:
矿物加工工程
·
煤炭浮选技术
✓ 已验证
产品关联
DOI
高影响因子
COMPOSITES PART A-APPLIED SCIENCE AND MANUFACTURING
·
2018
·
IF 4.514
Fuyao Liu,Zhuo Shi,Yubing Dong
In this paper, a modified epoxy emulsifier (MEE) was synthesised for preparing an aqueous epoxy sizing agent, which was used to reinforce interfacial adhesion of carbon fibre (CF)/epoxy composites. The sizing agent was evenly wrapped on the fibre surface with tiny particles, as well as increased the surface roughness of fibres; meanwhile, the activated carbon atoms on the surface of sized CF were further increased, as confirmed via SEM, AFM and XPS . The contact angle (CA) of fibres was observed via drop-on-fibre system. The results showed that the wettability of CF was significantly improved and the CA of CF was reduced by approximately 23°. According to the single-fibre fragmentation test, the interfacial shear strength of sized CF/EP composites increased by 70%–76%. The improvement of interfacial adhesion could be mainly attributed to the generation of chemical interaction bonds and the interface mechanical interlock of CF and the epoxy matrix.
研究领域:
材料科学
·
复合材料
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2021
·Vol. 11
·期 59
·37246-37253
·
IF 3.361
Minli Zeng,Kunyapat Thummavichai,Wenting Chen,Guangsheng Liu,Zhen Li,Xiaorong Chen,Chen Feng,Yi Li,Nannan Wang,Yanqiu Zhu
Size-controlled Fe3O4 nanoparticles doped with rare earth (RE) ions (La3+, Ce3+, and Dy3+) varying from 15 nm to 30 nm were successful synthesized by a hydrothermal method for potential applications in the fields of biomedicine, environmental protection and magnetic memory devices. They possessed good dispersibility, adjustable particle size and nearly spherical shape. The particle grain size was uniformly distributed and showed a low degree of agglomeration in comparison with undoped Fe3O4 nanoparticles. The FTIR results showed that the RE elements partially replaced Fe2+, occupied the octahedral position, and enhanced the vibration of the Fe–O bond. The XPS study further revealed that the valence states of La, Ce, and Dy are both positive trivalent. The XPS Fe 2p valence band spectra observed a shift in the peak position toward higher binding energy after RE doping, confirming the existence of RE ions in the octahedral position. This paper explains the mechanism of rare earth doping with Fe3O4, and clarifies the influence of the doping of different RE ions on its magnetic properties. The detailed analysis of RE-doped ferrite materials can open a new perspective in designing biomedical and spintronics materials with tailored properties by choosing suitable cation substitution.
研究领域:
材料科学
·
生物医学
·
环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Molecular Catalysis
·
2023
·
IF 4.6
Wujian Zhang,Weijian Ge,Yiping Jin,Mingming Dang,Panpan Zhang,Wenfeng Han,Ying Li,Zongjian Liu,Haodong Tang
Loaded noble metal redispersion is an important way to solve catalyst sintering. However, how to redisperse at low temperatures or carbon-based noble catalysts is a difficult problem. In this paper, we report this phenomenon occurring on PdCu alloy catalysts, where small-sized PdCu alloys can be realized from sintered large-sized PdCu alloys on carbon supports in a CO/O 2 atmosphere. The mechanism of redispersion is elucidated by XPS, TEM and DFT calculations. The main reason for the redispersion is the formation of the PdCuOx intermediate, which can easily migrate to the nearby catalyst surface and then be reduced to smaller PdCu alloy nanoparticles. This work provides a deeper understanding of the redispersion phenomenon and provides certain applications in industry.
研究领域:
催化
·
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2022
·
IF 7.139
Wenhui Zou,Yingcen Liu,Caicheng Song,Hua Lin,He Huang,Wanyue Ye,Rongwen Lu,Shufen Zhang
A series of PdO@MCM-41-x was in situ synthesized by a facile one-pot method, and their catalytic performance for dehydrogenation of formic acid was investigated. The PdO nanoparticles were immobilized in MCM-41 channel with small size of 2.2–2.5 nm due to the confinement of mesoporous silica . The initial turnover frequency (TOF) of as-prepared catalyst can reach 1096 h −1 at 323 K with 100% hydrogen selectivity. The hydrogen production activity was better than that of catalyst priorly reduced by hydrogen because of the gradual reduction of PdO nanoparticles and generation of fresh Pd(0) during the formic acid dehydrogenation process, which was confirmed by XPS characterization and catalytic system monitoring. It provides a new way for the preparation of simple and efficient catalysts for hydrogen production , which has great application potential.
研究领域:
化学
·
催化材料科学
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2013
·
IF 3.473
Lei Wang,Wen Liu,Ting Wang,Jinren Ni
For highly efficient removal of Cr(VI) from aqueous solutions, amino-functionalized titanate nanotubes (NH 2 -TNTs) with excellent adsorption performance have been synthesized by covalently grafting [1-(2-amino-ethyl)-3-aminopropyl]trimethoxysilane (AAPTS) onto protonated titanate nanotubes (HTNTs) with great amounts of surface hydroxyl groups. TEM and XRD results confirmed that the nanotubular morphology and crystal structure of HTNTs and NH 2 -TNTs were preserved. FTIR spectra demonstrated that AAPTS was covalently bonded on the surface of HTNTs. Batch adsorption experiments showed that pseudo-second-order kinetics model and Langmuir isotherm model fitted the adsorption data very well for both materials, and the Cr(VI) adsorption capacity on NH 2 -TNTs calculated by Langmuir model was up to 153.85 mg g −1 at initial pH 5.4 and 30 °C, much larger than that on HTNTs (26.60 mg g −1 ). Moreover, uptake of Cr(VI) ions onto NH 2 -TNTs could be completed within only 5 min for 95% adsorption of the maximum. Influence of different species of Cr(VI) under varying pH was also considered. FTIR and XPS analysis indicated that Cr(VI) ions were first exchanged with NO 3 - linked on the positively charged amino groups and then partially reduced to Cr(III). Afterwards, Cr(III) were then totally chelated with amino groups and no Cr(III) was detected in the solution after Cr(VI) adsorption at pH range of 1–12.
研究领域:
环境科学
·
材料科学
✓ 已验证
DOI
高影响因子
GEOCHIMICA ET COSMOCHIMICA ACTA
·
2015
·
IF 4.331
Congcong Ding,Wencai Cheng,Yubing Sun,Xiangke Wang
This article has been retracted: please see Elsevier Policy on Article Withdrawal ( https://www.elsevier.com/about/our-business/policies/article-withdrawal ). This article has been retracted at the request of the Executive Editor-in-Chief. Concern was raised about the EDX spectra shown by the insets of Figure 1D and the top two XPS spectra of Figure 9A (Fe 0 pH 3.5 and Fe 0 + B. Subtilis pH 3.5), as well as the FTIR spectra from Figure S6 and the XPS spectra from Figure S7B-E, which contained features and noise that indicated data fabrication. The corresponding authors were not able to provide reasonable explanations for these features and the Editor decided to retract the article. Moreover, the top EDX spectrum shown by the insets of Figure 1D is highly similar to the spectrum shown by the inset of Figure 1C of the article that the authors have previously published in the Journal of Hazardous Materials 280 (2014) 399–408 http://dx.doi.org/10.1016/j.jhazmat.2014.08.023 . One of the conditions of submission of a paper for publication is that authors declare explicitly that their work is original and has not appeared in a publication elsewhere. Re-use of any data should be appropriately cited. As such this article represents an abuse of the scientific publishing system. The scientific community takes a very strong view on this matter and apologies are offered to readers of the journal that this was not detected during the submission process.
研究领域:
环境科学
·
微生物学
✓ 已验证
DOI
高影响因子
ANALYST
·
2015
·Vol. 141
·期 1
·256-260
·
IF 4.107
Qiang-Qiang Sun,Min Wang,Shu-Juan Bao,Yu Chen Wang,Shuang Gu
The nanorods of cobalt phosphide have been prepared and evaluated as an electrocatalyst for non-enzyme glucose detection. The nanorods were used to modify the surface of an electrode and detect glucose without the help of an enzyme for the first time. The crystal structure and composition of cobalt phosphide were identified by XRD and XPS, respectively, and the morphology of the as-prepared samples was observed by FESEM and TEM. The electrochemical measurement results indicate that the CoP-based sensor exhibits excellent catalytic activity and a far lower detection potential compared to bare GCE. Specifically, the electrocatalytic mechanism of CoP in the detection of glucose was proposed based on a series of physical characterization methods, electrochemical measurements, and theoretical calculations.
研究领域:
材料科学
·
分析化学
·
生物医学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2022
·
IF 16.744
Jingjing Ren,Liuchun Zheng,Yaoming Su,Peipei Meng,Qianya Zhou,Hao Zeng,Tao Zhang,Huajian Yu
In order to treat heavy metal pollutants in acid mine drainage, zero-valent iron/phosphoric titanium dioxide (PTO-3nZVI and PTO-nZVI) was developed with phosphoric acid treatment and loading of zero valent iron and showed excellent adsorption of heavy metals. PTO-3nZVI and PTO-nZVI greatly improved the adsorption capacity for the targeted heavy metal Cd(II) (308 mg·g −1 for PTO-3nZVI and 206 mg·g −1 for PTO-nZVI) through complexation and coprecipitation. Additionally, competitive adsorption occurred between Cd(II) and coexisting heavy metal ions (Pb(II) and Cu(II)), resulting in different adsorption effects for PTO-3nZVI and PTO-nZVI, and their adsorption efficiencies decreased in the order Cu(II) > Pb(II) > Cd(II) for PTO-3nZVI and Pb(II) > Cu(II) > Cd(II) for PTO-nZVI. Based on these two aspects, X-ray photoelectron spectrometer (XPS) analyses and Density Functional Theory (DFT) calculations were used to characterize the adsorption behaviors of PTO-3nZVI and PTO-nZVI. In particular, competitive relationships for different heavy metals were clearly revealed by binding energies, Frontier Molecular Orbitals (FMOs) analyses, electrostatic potentials, and total potential and differential charge analyses of adsorption sites, binding sites and binding strengths.
研究领域:
环境科学
·
材料化学
·
重金属修复
·
计算化学
·
水处理
✓ 已验证
DOI
高影响因子
APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING
·
2023
·Vol. 129
·期 11
·1-7
·
IF 2.7
Yin Qianliu,Zhang Fanfan,Teng Yanlin,Peng Cong,Wang Chaonan,Jin Yonglong,Xu Meifeng,Xu Tian
Different concentrations of NH 4 Cl are introduced to MAPbI 3 precursor solution, planar MAPbI 3 perovskite films, and solar cells’ performance with or without NH 4 Cl have been studied. The NH 4 Cl/MAPbI 3 films exhibit increased grain size and narrowed grain boundaries. The light absorption of perovskite films with different concentrations of NH 4 Cl was also evaluated. To understand the growth of perovskite films with NH 4 Cl added to perovskite precursor solutions, XRD and XPS spectroscopy were conducted on different perovskite film samples. By adding NH 4 Cl, the MAPbI 3 film shows good crystal quality and the shift of Pb peaks indicates that NH 4 Cl is not physically mixed but chemically incorporated into MAPbI 3 films. We attribute the effect to Cl ions of NH 4 Cl combining with free lead ions of MAPbI 3 so as to fill the vacancy of volatile I ions in the NH 4 Cl–MAPbI 3 films. The 20 mg NH 4 Cl-based device showed an enhanced performance of a PCE of 13.67% compared to the device without adding NH 4 Cl with a PCE of 10.24%. The introduction of 20 mg NH 4 Cl achieved the best passivation effect. Using a 20 mg NH 4 Cl device, the trap density can be reduced to 0.84 × 10 16 cm −3 , resulting in more efficient charge removal from the surface and improved performance.
研究领域:
材料科学
·
太阳能
·
化学
✓ 已验证
DOI
高影响因子
SUPERLATTICES AND MICROSTRUCTURES
·
2013
·
IF 1.564
Zhaoxia Han,Dawei Zhang,Daohua Zhang,Ruijin Hong,Qinmiao Chen,Chunxian Tao,Yuanshen Huang,Zhengji Ni,Songlin Zhuang
Highly dispersed and near stoichiometric chalcopyrite CuInSe 2 nanoparticles were successfully synthesized via a facile and rapid one-pot method. For understanding the reaction pathway, the solid intermediates obtained at different stages of CuInSe 2 nanoparticles synthesis process were investigated in detail by powder X-ray diffraction (XRD), X-ray photoelectron spectrometer (XPS), energy dispersive spectroscopy (EDS) and Raman spectroscopy . The XRD patterns showed that the phase formation sequence was CuSe → CuInSe 2 . The XPS results indicated that the valences of Cu and Se in CuSe were +1 and −1, respectively. The chemical composition of the solid intermediates revealed the presence of the solid-state In–Se secondary phases in the synthesis process. However, no XRD signals or Raman signals of the solid-state In–Se secondary phase were observed. Based on the experimental results, the possible reaction pathway was proposed.
研究领域:
材料科学
·
化学
✓ 已验证
DOI
高影响因子
RSC Advances
·
2017
·Vol. 7
·期 51
·32146-32154
·
IF 3.108
Chengkai Pang,Yuqun Zhuo,Qiyu Weng
A series of Mn-exchanged SAPO-34 catalysts were synthesized and developed as catalysts for the low temperature selective catalytic reduction (SCR) of NO with ammonia in the presence of excess oxygen. 4Mn/SAPO-34 showed the highest SCR activity in the temperature range of 120–210 °C. The microstructure of zeolite supports, acidity, manganese species and reaction mechanism were investigated in detail by BET, NH3-TPD, UV-Vis, H2-TPR, XPS and in situ DRIFTS. Mn3+ and Mn4+ related species were proved to be the active sites for the SCR reaction. The Eley–Rideal mechanism was proved to be effective on 4Mn/SAPO-34 for the low temperature SCR reaction in which coordinated NH4+ species react with gas-phase NO to form an activated transition state and subsequently decomposed to N2 and H2O.
研究领域:
环境科学
·
催化化学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）