Journal of Spectroscopy
·
2015
·
IF 0.538
Y. J. Li,F. Y. Sun,Y. Zhou,L. Zeng
Different dispersants were added in the dispersion process to improve the efficiency of fluorite flotation. The types and dosage of dispersant on the improvement of fluorite flotation were investigated; when the sodium polyacrylate (SPA) was used as the dispersant and its addition is 0.5%, the concentrate grade of CaF2 increased from 90% to 98% and the fluorite recovery increased from 81% to 85%. Methods of X-ray powder diffraction (XRD), field emission scanning electron microscopy (FESEM), and Energy dispersive X-ray spectrometer (EDX) were used to characterize the sample. According to the analysis of results, the optimal sample consisted of CaF2 and very little CaCO3 in the size range of 0–5 μm. It could be concluded that the mechanism of improvement for the concentrate grade and recovery of CaF2 was attributed to the change of potential energy barrier which caused the separation of particles with different charge. All results indicate that SPA has a great potential to be an efficient and cost-effective dispersant for the improvement of fluorite flotation.
研究领域:
矿物加工工程
·
材料科学与工程
✓ 已验证
产品关联
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This article has been retracted: please see Elsevier Policy on Article Withdrawal ( https://www.elsevier.com/about/our-business/policies/article-withdrawal ). This article has been retracted at the request of the Executive Editor-in-Chief.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
MATERIALS CHEMISTRY AND PHYSICS
·
2022
·
IF 4.778
N.R. Khalid,Hamid Ishtiaq,Faisal Ali,M.B. Tahir,Sumaira Naeem,A. Ul-Hamid,M. Ikram,T. Iqbal,M. Rizwan Kamal,Hussein Alrobei,Meshal Alzaid,A. Dahshan
The fast pace of industrial growth during the current decade has seen a large family of dyes employed copiously in the production of various products such as paper and ink. These dyes pollute earth's ecosystems. Researchers look at various ways to degrade these dyes including the use of suitable nanomaterials . ZnO is an important semiconductor material that can be employed for this purpose. In this research work, we optimized the photocatalytic capability of ZnO by co-doping it with 1–7 wt% of Bi and N. The synthesized Bi and N co-doped ZnO nanorod samples showed excellent photocatalytic behavior towards Rhodamine-B (RhB). It was confirmed using XRD and SEM that (5, 2.5) wt.% Bi/N co-doped ZnO nanorods exhibited unique morphology and structure. EDX successfully assessed the elemental composition of the synthesized samples. To provide further insight into its microstructure, the HRTEM and SAED analysis were performed. Optical properties were determined using PL and UV–Visible spectroscopy. The prepared nanorod material degraded almost 89% of RhB in 180 min. The superior degradation ability of co-doped ZnO material when exposed to visible portion of sunlight spectrum is credited to the decrease in the recombination rate of charges and an increase in the depth penetration of photons. The degradation efficiency of Bi/N co-doped ZnO material is enhanced due to reduced recombination rate and increased production of number of defects and oxygen vacancies .
研究领域:
材料科学
·
环境科学
·
化学
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2017
·
IF 3.582
Yinghui Sun,Guojie Zhang,Jiwei Liu,Peiyu Zhao,Peng Hou,Ying Xu,Riguang Zhang
CH 4 CO 2 reforming to syngas was investigated over three different activated carbon catalysts. To better understand the influence of the supports on the catalytic properties , catalysts were analyzed by some characterization methods, such as nitrogen adsorption–desorption isotherms, XRD , H 2 -TPR, NH 3 -TPD, CO 2 -TPD, FTIR, TEM and EDX . The results showed that the catalyst with AC 2 as the support provided the best catalytic activity . The CH 4 conversion and CO 2 conversion were 92% and 98% at 900 °C, respectively; best selectivity with the H 2 /CO ratio was close to 1 among the three supports used. It also showed a better stability at 900 °C. H 2 -TPR analysis showed that Co species in Co/AC 2 catalyst were strong interaction with the support. It was observed that active metals were well dispersed on the AC 2 support by the TEM. In addition, the ratio of CH 4 /CO 2 also had great influence on the CH 4 and CO 2 conversion.
研究领域:
催化
·
化学工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
Molecular Catalysis
·
2018
·
IF 0
Shanshan Jie,Congqiang Yang,Yuan Chen,Zhigang Liu
The highly dispersed active sites are desirable to optimize the atom efficiency. In this study, a series of novel cobalt grafted in N-doped carbon (Co-N-C) catalysts for selective oxidation of ethylbenzene are synthesized by heating a solution of cobalt porphyrin and peptides in ionic liquids, which are also characterized by techniques such as FT-IR, XRD, SEM-EDX, HR-TEM, and XPS. The results show that the as-prepared catalysts have an attractive catalytic performance, namely, 40% of ethylbenzene conversion and 75% of selectivity to acetophenone. Especially, the activity and selectivity of the as-prepared catalysts remain almost similar even after the 10th run. Moreover, the modified-complexometry method is verified to improve the dispersion of metal active sites. The remarkable catalytic performance of the as-prepared catalysts is attributed to the highly dispersed active sites and strong interactions between Co and N species in Co-N x moieties.
研究领域:
催化
·
材料科学
·
化学工程
·
分析化学
✓ 已验证
产品关联
DOI
POLYMER DEGRADATION AND STABILITY
·
2019
·
IF 3.78
Tian Liu,Xingrong Zeng,Xuejun Lai,Hongqiang Li,Yanlin Wang
Organosilicon materials with high capacity of organic-to-inorganic conversion at elevated temperature are always favorable in the field of high-temperature-resistant materials, flame retardant materials, chemical engineering and functional materials in electrical engineering. In this work, it was found out that the platinum-nitrogen catalytic system could obviously enhance the organic-to-inorganic conversion efficiency of silicone rubber (SiR) at elevated temperature. The residual rate of Pt/N/SiR (SiR containing 0.33 phr Karstedt's catalyst (Pt) and 2 phr nitrogenous silane (N)) at 1000 °C was significantly improved from 3.0% to 44.8% in comparison with SiR and its thermal stability was also enhanced. DLS , TEM and UV–vis absorption spectrometry revealed that the platinum in Karstedt's catalyst would aggregate at elevated temperature and deteriorate its catalytic activity for organic-to-inorganic conversion of SiR. And the addition of nitrogenous silane can efficiently inhibit the aggregation and retain the high catalytic efficiency of platinum. A thorough TG-FTIR study, together with SEM/EDX and XPS analyses suggested that the platinum-nitrogen system might suppress the intramolecular cyclic transition and enhance the radical coupling between polymer chains of SiR during thermal degradation , which resulted in the high capacity of organic-to-inorganic conversion of Pt/N/SiR at elevated temperature.
研究领域:
材料科学
·
化学工程
·
电气工程
✓ 已验证
产品关联
DOI
高影响因子
Journal of Environmental Chemical Engineering
·
2022
·
IF 7.968
Zhong Sun,Yihan Yin,Yupeng An,Chao Deng,Ziyu Wei,Zijiang Jiang,Xixin Duan,Xiaohui Xu,Jing Chen
A cost-efficient and simple method, grafting sodium sulfonate groups (−SO 3 Na) onto carboxymethyl cellulose (CMC), was developed to form hydrogel adsorbents for the removal of poisonous metals including Cu(Ⅱ) and Zn(Ⅱ) from wastewater. In this work, cellulose-based hydrogels (CMC-g-P(AA-co-SS)) were prepared using acrylic acid (AA) and sodium styrene sulfonate (SS). FTIR, XPS , SEM , and EDX were employed to analyze the surface morphology and structure of CMC-g-P(AA-co-SS). The results revealed that the synergistic effect of −SO 3 Na and carboxylate groups (−COO − ) facilitated the adsorption of heavy metals. Moreover, introducing AA and SS enhanced the swelling degree of CMC hydrogels. The results of adsorption experiments showed that high adsorption efficiencies were obtained for Cu(Ⅱ) and Zn(Ⅱ) (200.44 mg/g and 192.28 mg/g, respectively) within 180 min. The adsorption isotherm and kinetics indicated that the monolayer chemical adsorption dominated the process. After 5 cycles, the adsorption activity of CMC-g-P(AA-co-SS) remained high, with the adsorption capacity for Cu(Ⅱ) and Zn(Ⅱ) being 93.3% and 78.3% of the original, respectively. Thus, the CMC-g-P(AA-co-SS) is a promising adsorbent candidate for the removal of poisonous metals from wastewater.
研究领域:
环境科学
·
化学工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY
·
2023
·Vol. 332
·期 1
·23-32
·
IF 1.6
Ou Minrui,Li Wanying,Zhang Zihui,Xu Xiaoping
In this work, we synthesized a novel β -cyclodextrin/poly(2-acrylamide-2-methylpropionic acid)/attapulgite (CAMA) hydrogel for uranium(VI) adsorption. Various instrumental techniques such as FTIR, SEM, EDX, and TGA were utilized for characterization of the CAMA. Simultaneously, different important parameters, in specific pH, time, initial uranyl ion concentration and temperature were investigated to evaluate the optimal conditions of the adsorption process. The experiments proofs that the adsorption follows the pseudo-second-order kinetic model so as the Langmuir model, and revealed the maximum adsorption capacity of 434.78 mg g −1 at 298.15 K. Regeneration studies further sighted out the good reusability of the synthesized CAMA hydrogel.
研究领域:
环境科学
·
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2020
·
IF 10.652
Yuezhou Wei,Khalid A.M. Salih,Kamal Rabie,Khalid Z. Elwakeel,Yasser E. Zayed,Mohammed F. Hamza,Eric Guibal
Alginate-PEI beads are functionalized by phosphorylation and applied for the sorption of Nd(III) and Mo(VI). The successful grafting of phosphoryl groups (as tributyl phosphate derivative) is characterized by FTIR and XPS analysis, elemental analysis, titration (pH PZC ), TGA, BET and SEM-EDX analyses. The multi-functional characteristics of the sorbent (i.e., carboxylic, hydroxyl, amine and phosphate groups) contribute in the binding of metal ions having different physicochemical behaviors. The sorption of Nd(III) is strongly increased by phosphorylation, while for Mo(VI) the enhancement is rather limited. Optimum sorption occurs at pH 3–4: maximum sorption capacity reaches up to 1.46 mmol Nd(III) g −1 and 2.09 mmol Mo(VI) g −1 ; sorption isotherms are fitted by the Langmuir equation. The equilibrium is reached within 30–40 min and the kinetic profiles are simulated by the pseudo-first order rate equation. The coefficients of the effective diffusivity are close to the self-diffusivity of Nd(III) and Mo(VI) in water; as a confirmation of the limited impact of resistance to intraparticle diffusion in the kinetic control. The sorbent is selective for Nd(III) over Mo(VI) and other alkali-earth or base metals (at pH close to 2.5–3). Metals can be readily desorbed using 0.2 M HCl/0.5 M CaCl 2 as the eluent. The loss in sorption does not exceed 5% at the fifth cycle, while desorption remains complete. A series of treatments (including acidic leachate, cementation, precipitation, sorption and elution) is successfully applied for the recovery of rare earths from Egyptian ore; with enrichment in the oxalate precipitate of Nd(III), Gd(III), Sm(III) and Eu(III).
研究领域:
环境科学
·
材料科学
·
化学工程
·
分析化学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Environmental Chemical Engineering
·
2023
·
IF 7.7
Yuan Chen,Yuancai Chen,Yexia Qin
In the present study, we found that nanoparticles (Pd-NPs) were biosynthesized by Bacillus wiedmannii MSM ( B. wiedmannii MSM) with endogenous carbon under O 2 condition, and more favorablity under N 2 purging condition. XRD results indicated that crystal planes of Pd-NPs were attributed to Pd 0 (111), Pd 0 (200), Pd 0 (220), and Pd 0 (311), respectively. TEM and STEM-EDX results showed that the bio-reduction of Pd (II) ( k pd,1 =4.799 min −1 ) occurred predominately in periplasm space. FTIR results showed that the -COOH, -OH, and -NH 2 were the main groups participating in the removal of Pd (II). The aerobic reduction of Pd (II) by B. wiedmannii MSM was proposed, including extracellular superoxide radicals produced by NAD(P)H oxidases , endogenous electron donors, and O 2 -insensitive hydrogenase. These studies provide new methods and insights for reduction of Pd (II).
研究领域:
环境科学
·
材料科学
·
微生物学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THE ELECTROCHEMICAL SOCIETY
·
2015
·Vol. 162
·期 6
·E68
·
IF 3.266
Xinhua Cheng,Diyong Tang,Dingding Tang,Hua Zhu,Dihua Wang
Electrochemical splitting of Co3O4 into cobalt powder and oxygen was realized by electrolysis in molten Na2CO3-K2CO3 at 1023 K using a solid oxide pellet cathode and a Ni11Fe10Cu alloy inert anode. The electro-reduction mechanism of Co3O4 was investigated in details by cyclic voltammetry measurements and potentiostatic electrolysis in a three-electrode cell combining with the composition and morphology characterization of the electrolytic products. The electro-reduction of Co3O4 in Na2CO3-K2CO3 melt mainly involves two steps by electrochemical formation of intermediate product of CoO and then the CoO is reduced to cobalt metal. NaxCoO2 intermediate was not detected by XRD measurements and EDX analysis, different from the electro-reduction of Fe2O3 in this melt. However, the particle size and morphology of the intermediate CoO is found to be dependent of the applied potential in the range of −0.35 V to −0.75 V vs. Ag/Ag2SO4 reference electrode. Metallic cobalt powder was prepared by potentiostatic electrolysis at potential more negative than −1.25 V (vs. Ag/Ag2SO4) or by constant cell voltage electrolysis under a cell voltage higher than 1.7 V using a Ni11Fe10Cu inert anode. A high current efficiency of 95.3% and a low electrolysis energy consumption of 2.16 kW·h/kg-Co represents a novel high efficiency and green process for Co extraction. The Co product is a mixture of FCC and HCP structure, which is affected by the applied cell voltage and deserves further investigation to recognize the structure controllable condition and mechanism.
研究领域:
材料科学
·
电化学
·
冶金工程
·
能源工程
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CLAY SCIENCE
·
2020
·
IF 4.605
Yixuan Yang,Runliang Zhu,Qingze Chen,Haoyang Fu,Qiuzhi He,Jianxi Zhu,Hongping He
Multifunctional adsorbents based on montmorillonite (Mt) have been of highly concerns due to their unique 2D layer structures and impressive co-adsorption performances. To further enhance the support ability and reactivity, a strategy was developed in this study to enable the co-existence of porous nanosilica (PNS) and hydrophobic interlayer spaces in Mt structure, and a novel multifunctional adsorbent (iron modified-acidified organo-Mt, Fe-AOMt) was then synthesized, aiming to simultaneously remove hydrophobic contaminants , oxyanion contaminants and heavy metals in water. The combination of XRD , FTIR and TEM verified the co-existence of amorphous PNS and layered structure (containing intercalated surfactant) in the acidified organo-Mt (AOMt), and results of STEM-EDX revealed uniform distribution of Fe after the further introduction of Fe hydroxides to AOMt. Additionally, pore structure analyses suggested that the acid activation can obviously increase the pore volume and specific surface area of OMt. Batch adsorption experiments revealed that Fe-AOMt as a promising multifunctional adsorbent was able to effectively and simultaneously remove nitrobenzene , phosphate, and Cd(II) in the multi-contaminant system. The synergetic adsorption of phosphate and Cd(II) on Fe-AOMt suggested the formation of ternary surface complexes (≡Fe–P–Cd), while the pH-independent uptake of nitrobenzene was hardly influenced by adsorption of phosphate and Cd(II), implying dissimilar adsorption mechanisms. The co-adsorption mechanism on Fe-AOMt was further revealed via XPS . Our work provided a novel and efficient Mt-based multifunctional adsorbent with a newly-proposed structure, which was a preliminary exploration of diversifying locations and types of active sites in Mt structure.
研究领域:
环境科学
·
材料科学
·
化学工程
·
水处理
✓ 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）