SEPARATION AND PURIFICATION TECHNOLOGY
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2025
·
IF 9
Junyi Xiang,Xi Lu,Hongru Rao,Luwei Bai,Qingyun Huang,Xuewei Lv
The separation of vanadium and chromium from vanadium-chromium slag constitutes the greatest bottleneck in the exploitation and utilization of high-chromium vanadium-titanium magnetite, which mainly results from the insufficient understanding of the behavior of similar elements vanadium and chromium during the extraction process. In this research, a series of spinels FeV x Cr 2- x O 4 (0 ≤ x ≤ 2) were synthesized via the high-temperature solid-state method, and their sodium roasting and leaching behavior were comprehensively analyzed. The transformation rules of sodium vanadate and chromate were investigated by XRD, SEM-EDS, FTIR, and thermodynamic calculation. The results indicate that in the FeV x Cr 2- x O 4 (0 ≤ x ≤ 2) − Na 2 CO 3 system, at 300°C, a portion of chromium spinel phase is preferentially and slowly oxidized to Cr 2 O 3 , while the vanadium spinel rapidly oxidizes to form NaVO 3 at 400°C. Above 500°C, NaVO 3 further reacts with Na 2 CO 3 to form Na 4 V 2 O 7 , and Na 2 CrO 4 also begins to form concurrently. As the proportion of Cr in FeV x Cr 2- x O 4 increases, both the leaching efficiencies of vanadium and chromium from the sodium-roasted samples decrease, with the leaching efficiency of chromium decreasing more significantly. Significant competitive and synergistic effects between vanadium and chromium are observed in the roasting of FeV x Cr 2- x O 4 with Na 2 CO 3 . This study is expected to provide theoretical support for the development of efficient vanadium-chromium extraction processes.
研究领域:
冶金学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2024
·
IF 8.3
Zhuocheng Tian,Hang Liu,Mengyuan Cheng,Lianmeng Cui,Rongyu Zhang,Xu Yang,Di Wu,Dongxue Wang,Jianlong Xia
Aqueous zinc-ion batteries are emerging as promising sustainable energy-storage devices. However, their cyclic stability is still a great challenge due to the inevitable parasitic reaction and dendrite growth induced by water. Herein, a cosolvent strategy based on competitive effect is proposed to address the aforementioned challenges. Ethanol with a higher Gutmann donor number demonstrates lower polarity and better wettability on the Zn surface compared with water, which endows ethanol with the ability of minimizing water activity by weakening H bonds and preferentially adsorbing on the Zn electrode. The above competitive advantages synergistically contribute to inhibiting the decomposition of free water and dendrite growth. Besides, an organic–inorganic hybrid solid–electrolyte interphase layer is in situ built based on ethanol additives, where organic matrix suppresses water corrosion while inorganic fillers promote fast Zn2+ diffusion. Consequently, the electrolyte with ethanol additives boosts a high reversibility of Zn deposition, long-term durability, as well as superior Zn2+ diffusibility in both Zn half-cells (Zn||Cu and Zn||Zn batteries) and Zn full cells (Zn||PTCDA and Zn||VO2 batteries). This work sheds light on a universal strategy to design a high-reversible and dendrite-free Zn anode for stable aqueous batteries.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
MICROCHEMICAL JOURNAL
·
2024
·
IF 4.9
Xuefei Zhang,Fanfei Min,Lingyun Liu,Lujun Wang,Qi Liu
Ca 2+ is an important ion in industrial wastewater such as coal slurry water. The concentration of Ca 2+ directly affects the water quality of recycled water, the physicochemical properties of particle surfaces, and the effectiveness of coal beneficiation. However, the determination of Ca 2+ in coal slurry water is influenced by other coexisting metal ions (M: K + , Na + , Mg 2+ , and Al 3+ ) in the system. The complexation color development – visible spectrophotometry (CCDVS) has been proven to be a rapid and accurate way to determine Ca 2+ . This study investigates the impact and mechanism analysis of factors such as the concentrations of coexisting ions (K + : 0–15 mg/L, Na + : 0–2000 mg/L, Mg 2+ : 0–20 mg/L, Al 3+ : 0–0.05 mg/L) and valence states (monovalent, divalent, trivalent) on the accurate determination of Ca 2+ using the CCDVS method. All ions are interested in the indicator, with the light absorption intensity order of Al 3+ (Abs = −1.783) > Mg 2+ (Abs = −1.723) > Ca 2+ (Abs = −1.248) > K + (Abs = −0.268) > Na + (Abs = −0.075) under the same ions concentration (e.g. 16 mg/L). Interestingly, the absorbance of Ca–M mixed solutions shows different trends. For example, adding Na + decreases the absorbance value of Ca 2+ , with a decrease in Abs of 0.065 when the Na + concentration is 2000 mg/L. This indicates a competitive relationship between the complexation color development reaction of Ca and Na due to the same reaction mechanism. However, for Ca–Mg mixed solutions, when the Mg 2+ concentration increases to 15 mg/L, the increase in Abs is 0.078, attributed to the stronger absorption of Mg 2+ occupying the adsorption sites of Ca 2+ . On the contrary, at industrial concentrations, the influence of K + (0–20 mg/L) and Al 3+ (0–0.05 mg/L) on Ca 2+ detection can be ignored. Complementary characterization (XRD, XPS) and DFT theoretical calculations indicate that complexation color development reaction depends on the adsorption of metal ions on the sulfonic acid sites on the indicator. Other metal cations compete with Ca 2+ for the same adsorption sites, and the reactivity of metal ions with the indicator is as follows Al 3+ > Mg 2+ > Ca 2+ > K + > Na + . Therefore, this study provides technical and theoretical support for the development of highly selective Ca 2+ detection methods, aiding in the rational control of chemical agent dosages.
研究领域:
环境科学
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分析化学
✓ 已验证
产品关联
DOI
高影响因子
Processes
·
2024
·Vol. 12
·期 11
·2598
·
IF 2.8
Xiaofei Li,Tianfu Li,Xiaohu Jin,Yanfu Wei,Yanping Bao,Qian Yao,Fuhua Li,Weicheng Xu,Xiaolian Wu
The adsorption of toxic metals onto iron oxides is a prevalent geochemical process in natural environments. Organic acids are known to modify the adsorption features of toxic ions through either competitive or cooperative effects. Nowadays, the toxic metal adsorption influenced by organic acids on iron oxides with varying facet exposures is not fully understood. This study explored how L-Aspartic acid (LA) influences Cr(VI) adsorption on two different exposure facets of lepidocrocite through batch adsorption experiments, in situ ATR-FTIR spectroscopy, and 2D-COS analysis. The results reveal that LA competes for available binding sites on lepidocrocite, consequently inhibiting the adsorption of Cr(VI). Rod-shaped lepidocrocite (R-LEP) owns more (001) facets and shows stronger Cr(VI) adsorption and LA competition than plate-like lepidocrocite (P-LEP), which mainly has (010) facets. The data for Cr(VI) uptake on both P-LEP and R-LEP within the effect of LA are well-fitted by the pseudo-second-order kinetics and the Freundlich isotherm model, suggesting chemical interaction as the dominant process for Cr(VI) coordination on lepidocrocite. Cr(VI) ions favor interaction with R-LEP over P-LEP, forming inner-sphere complexes on (001) facets. Concurrently, LA’s carboxyl groups can compete for the active sites on the lepidocrocite surfaces, engaging in anion exchange with hydroxyl groups, and forming outer-sphere and inner-sphere structures. This competitive effect is particularly pronounced in the R-LEP system. The current findings are expected to broaden insights into how the exposed facets of lepidocrocite influence the fate of Cr(VI) in the organic acid coexistence environment.
研究领域:
环境科学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
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2020
·
IF 6.551
Cong Xue,Ling Zhu,Sicong Lei,Mengping Liu,Chengyi Hong,Lei Che,Junliang Wang,Yuping Qiu
In this study, the adsorption behaviors and mechanisms of Pb(II) and Zn(II) by animal-derived biochar (ADB) in single and binary metal systems were comparatively investigated. ADB contains considerable amounts of Ca/P components and is mainly composed of hydroxyapatite (HAP), which plays an important role in the adsorption of Pb(II) and Zn(II). The maximum adsorption capacities of Pb(II) and Zn(II) on ADB were in the order of Zn(II)-single (3.23 mmol g − 1 ) > Pb(II)-single (2.74 mmol g − 1 ) ≈ Pb(II)-binary (2.71 mmol g − 1 ) > Zn(II)-binary (2.31 mmol g − 1 ). In the single metal system, approximately 99.9% of the adsorbed Pb(II) existed as Pb 5 (PO 4 ) 3 Cl, while the dominant adsorption mechanism of Zn(II) was cation exchange, followed by precipitation, accounting for 78.0%–80.6% and 19.4%–21.5% of the adsorption capacity, respectively. These findings were verified by X-ray diffraction refinement, X-ray photoelectron spectroscopy, metal speciation modeling, and Ca(II) exchange experiment. In the binary metal system, the proportion and form of Pb(II) precipitate remained unchanged. However, the binding of Zn(II) to ADB was completely dependent on the cation exchange with Ca(II), and no remarkable Zn(II) precipitation was observed. Phosphate released from HAP preferentially precipitated with Pb(II) than with Zn(II) when they coexisted. Consequently, Pb(II) competition may alter the Zn(II) adsorption mechanism on ADB. Nonetheless, ADB could serve as an efficient biochar for the simultaneous immobilization of Pb(II) and Zn(II) via different mechanisms.
研究领域:
环境科学
·
土壤学
✓ 已验证
DOI
PubMed
高影响因子
JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
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2021
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IF 5.279
Keying Zhang,Guang Zhu,Yunlong Wei,Li Zhang,Yizhong Shen
Accurately monitoring mercury ions (Hg2+) in food and agriculture-related matrixes (e.g., green tea) is of great significance to safeguard food safety. Here, we employed upconversion nanoparticles (UCNPs) and gold nanoparticles (AuNPs) to engineer a cysteine (Cys)-assisted anti-Stokes luminescence sensing platform (UCNPs–AuNPs) for precisely detecting residual Hg2+ in green tea through the competition effect. Initially, AuNPs could effectively quench the luminescence of UCNPs through the luminescence resonance energy transfer process, which was then interrupted by Cys-triggered AuNP aggregation via Au–S, thereby restoring UCNP luminescence. Interestingly, owing to the competition effect with AuNPs toward Cys, Hg2+ could weaken the luminescence restoring efficiency, achieving a Hg2+ concentration-dependent luminescence change. On this basis, a facile, reliable, and sensitive upconversion luminescence sensing platform for monitoring residual Hg2+ in green tea was successfully established. This study offers a novel insight into integrating the competition effect and anti-Stokes luminescence for food- and agriculture-related contaminant monitoring.
研究领域:
食品科学
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分析化学
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环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2019
·
IF 8.355
Huicai Wang,Zhenwen Wang,Ruirui Yue,Feng Gao,Ruili Ren,Junfu Wei,Xiaolei Wang,Zhiyun Kong
In order to solve the problem of coexistence pollution of heavy metal ions in real water environment, a polydopamine (PDA) modified polypropylene non-woven adsorbent was rapidly prepared by one-step method based on mussel-inspired chemistry. The mussel inspired chemical reaction was accelerated by combining oxidants with diamine. The interaction between coexisting metal ions severely inhibits the removal of adsorbents with single active site, a multifunctional non-woven absorbent (PP/PDA/ASA) was synthesized through introducing salicylic acid groups at the end of PDA to increase the type of adsorption sites and address the issue of low removal efficiency caused by competitive effects in multicomponent system. The synthesized adsorbent was characterized by SEM, FTIR spectroscopy and XPS techniques. Meanwhile, the adsorption capacity of Cu(II), Cd(II) and Pb(II) on PP/PDA/ASA was systematically studied in single and multi-target systems under various conditions. The findings indicated that the PP/PDA/ASA could remove 90% of Cu(II) and Pb(II), and 80% of Cd(II) from 5 mg/L of Cu(II)/Cd(II)/Pb(II) mixed solution at the sorbent:solution mass ratio of 1:1000. Noticeably, the adsorption capacity and rate of the metal ions in the multi-component system were reduced, indicating the strong competitive adsorption in the multi-component system. XPS analysis showed that various functional groups (amino, hydroxyl and carboxyl groups) on the surface of PP/PDA/ASA were involved in the adsorption of heavy metal ions. The adsorption mechanism included coordination and ion exchange between metal ions and functional groups, while the adsorption mechanisms of Cu(II), Cd(II) and Pb(II) were different.
研究领域:
环境科学
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材料科学
✓ 已验证
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
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2022
·
IF 4.326
Yu Qiao,Yonghou Xiao,Shuohan Yang,Qidong Zhao,Wenkai Zhao,Gaohong He
Recently, the investigation of high-efficiency adsorbents for CO adsorption and separation has gradually become a research focus with carbon energy chemistry developing and environmental protection requirement enhancing. The adsorption performance of CO would be devitalized under a humid environment, although the traditional molecular sieves could serve as an effective adsorbent toward CO adsorption under an anhydrous atmosphere. In this work, a strategy of silanization modification was proposed to enhance the performance of CO adsorption by restraining the surface occupied by competitive water molecules due to the hydrophilic nature of silica hydroxyl groups on the 5A molecular sieves. A series of hydrophobic CO adsorbents (X-B-5A) were successfully prepared via impregnation using butyltrichlorosilane (BTS) as a hydrophobic agent, toluene as a dispersion solution, and commercial 5A molecular sieves as a raw material. The effect of different concentrations of BTS in toluene solution on hydrophobicity and CO adsorption performance was investigated. The results showed that the hydrophobicity of X-B-5A was significantly increased after silanization modification. Additionally, the water contact angle of 0.004-B-5A increased from 20° to 154°, and the static water vapor adsorption capacity was reduced from 27.5 to 6.0% at 35 °C. The CO static adsorption capacity of 0.004-B-5A still reached 1.54 mmol/g, which was only 14.6% lower than that of pristine 5A molecular sieves. Additionally, the dynamic adsorption capacity of CO over the as-prepared X-B-5A was significantly enhanced compared to pristine 5A molecular sieves in the presence of moisture. The as-prepared hydrophobic adsorbents exhibited satisfactory CO adsorption performance and high thermal stability in a humid environment. This work presents a novel strategy for the preparation of adsorbents toward CO adsorption employed under a high relative humidity environment.
研究领域:
材料科学
·
环境化学
·
吸附分离技术
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
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2020
·
IF 9.038
Xiang-Dong Xue,Cheng-Ran Fang,Hai-Feng Zhuang
In this work, the hypothesis that thermoplastic polyurethane (TPU) microplastics (MPs) could form complex toxic pollution by absorbing both antibiotics and heavy metals simultaneously was proposed. The unique features of the adsorption of Cu(II) and oxytetracycline (OTC) on the pristine TPU and photo-aged (aged) TPU MPs in single and coexisting system were investigated, which included the kinetics, isothermal equilibrium and thermodynamics. The possibly synergistic or competitive effects between Cu(II) and OTC were also evaluated. The results showed that the adsorption process of Cu(II) and OTC could be described well by pseudo-second-order kinetic equation . The entire process could be divided into two stages: internal diffusion and external diffusion. The Sips model could give good fitting for the isothermal adsorption equilibrium. The thermodynamic parameters depicted the endothermic nature of adsorptions and the process was spontaneous. In the coexisting system, synergistic or competitive effects depended critically on the ratio of concentrations (Cu(II) vs OTC). When the ratio was 1:1, Cu(II) significantly enhanced the adsorption of OTC, while OTC showed a weak effect on Cu(II) adsorption. The synergies could be attributed to the formation of Cu(II)-OTC complex and the bridging effect of Cu(II). Overall, the adsorption capacity of aged TPU was higher than that of pristine TPU, which was due to the differences in morphological characteristics and functional groups. FTIR studies revealed that ester carbonyl and acylamino groups in the TPU may be involved in the adsorption of Cu(II) and OTC.
研究领域:
环境科学
·
污染生态学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
·
2011
·Vol. 13
·期 47
·21116-21120
·
IF 3.454
Shengtong Sun,Peiyi Wu
Herein, noble metal nanoparticle (Au or Ag NP) decorated graphene sheets, fabricated according to a facile one-pot environmentally friendly method, are used as good substrates for the investigation of the combined surface-enhanced Raman scattering (SERS) effect, where both the electromagnetic mechanism and the chemical mechanism effects coexist among the Au or Ag NPs, graphene sheets and the absorbed analytes. Our results show that, in aqueous solution, the SERS effect of both the Au and Ag NPs on the absorbed probe molecules and on graphene is competitive, which varies dependent on the species and the concentration of the absorbed probe molecule. By a detailed comparison of three probe molecules (rhodamine 6G, nile blue A, and 4-aminobenzenethiol) with different coupling abilities to the graphene sheets, we finally attribute this phenomenon to the result of the strong suppressing effect of the macrocyclic probe molecules on the SERS of graphene, induced by charge transfer, as the probe molecules are coupled to the graphene sheets. This competitive effect is a non-ignorable phenomenon when graphene/Au or Ag nanocomposites are used as SERS substrates, and our study may deepen our understanding of the SERS mechanism.
研究领域:
纳米材料学
·
分析化学
·
光谱学
·
生物传感
·
物理化学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）