CHEMOSPHERE
·
2022
·
IF 8.943
Heng Li,Kaisheng Gong,Xiaoying Jin,Gary Owens,Zuliang Chen
Since antimony (Sb) is a toxic metalloid cost-effective method for the simultaneous removal of the two major Sb species from mining wastewater has attracted much attention. In this study, phytosynthesized iron nanoparticles ( n Fe) prepared using a eucalyptus leaf extract were successfully used to simultaneously remove Sb(III) and Sb(V) via an adsorption and oxidation mechanism with removal efficiencies of 100 and 97.7% for Sb(III) and Sb(V), respectively. Advanced analysis using X-ray photoelectron spectroscopy (XPS), ion chromatography-atomic fluorescence spectroscopy (IC-AFS), and electrochemical analysis confirmed that Sb(III) was oxidized to Sb(V) by Fe(III) on the n Fe surface while Scanning Electron Microscopy (SEM) and Energy Dispersive Spectroscopy (EDS) indicated that both Sb(III) and Sb(V) were adsorbed onto n Fe. Adsorption of both Sb(III) and Sb(V) best fit the Langmuir adsorption model with R 2 of 0.999 and 0.989, respectively and both followed pseudo-second-order kinetics with R 2 of 0.999 and 0.981, respectively. Furthermore, the adsorption rate of Sb(III) was faster than that of Sb(V) due to inner-sphere complex formation, and the Fe–O bonds in the asymmetric tetrahedron structure of Sb(III) were easier to break due to a lower energy barrier (0.863 eV). Consequently, a simultaneous removal mechanism of Sb(III) and Sb(V) was proposed. Finally, n Fe was used practically to remove Sb in mining wastewater with a removal efficiency of 93.5%, demonstrating that n Fe have significant potential to remove Sb in contaminated mining wastewaters.
研究领域:
环境科学
·
纳米技术
·
水处理
·
材料科学
✓ 已验证
DOI
高影响因子
POLYMER DEGRADATION AND STABILITY
·
2022
·
IF 5.204
Xinming Ye,Yu Feng,Panpan Tian,Zhimao Li,Yingchun Li,Wensheng Wang,Jie Li,Liang Qiao,Kun Wang,Wenchao Zhang,Ye-Tang Pan,Rongjie Yang
Despite remarkable advances in developing flame retardants and smoke suppressants for epoxy resin (EP), engineering nitrogen-containing polyhedral oligomeric silsesquioxane (N-POSS) to impart superior fire safety properties to EP has remained an intractable challenge. In this work, two nitrogen-containing polyhedral oligomeric silsesquioxanes (N-POSSs), namely, aminoethyl-aminopropyl-hepta-phenyl polyhedral oligomeric silsesquioxane (AEAP-POSS) and aminopropyl-hepta-phenyl polyhedral oligomeric silsesquioxane (AP-POSS), were synthesized through the “corner-capping” reaction. The molecular structures of N-POSSs were fully characterized by FTIR, 1 H NMR, 29 Si NMR and MALDI-TOF MS, and the synthesized AEAP-POSS and AP-POSS were introduced into EP to solve the shortcomings of flammability. TGA results showed that the incorporation of 4 wt% N-POSS nanoparticles distinctly improved the char residue at 800 °C, which significantly enhanced the thermal stability of the EP composites. When 4 wt% of AP-POSS was introduced into EP, reductions in the peak of heat release rate (p-HRR), fire growth index (FGI), peak of smoke production rate (p-SPR), and the peak of CO production rate (p-COP) reached to 60.6%, 70.2%, 52.3% and 60.4%, respectively. Subsequently, TG-FTIR and XPS were utilized to investigate the flame retardancy and smoke suppression mechanism. Our work presented a considerable advancement for the facile fabrication of flame retardants based on nitrogen-containing polyhedral oligomeric silsesquioxane compounds.
研究领域:
材料科学
·
化学工程
·
高分子科学
·
消防安全工程
✓ 已验证
DOI
高影响因子
VACUUM
·
2023
·
IF 4
Chaoqun Yan,Zhiliang Cheng,Xuan Zhang,Juan Wei,Qian Xu
The photocatalytic efficiency of hematite (α-Fe 2 O 3 ) is limited by its photoexcited state lifetime and diffusion length. By adjusting the surface structure, the photogenerated electron pairs can migrate to the surface and the charge recombination can be suppressed, which can effectively solve these problems and improve the photo-Fenton performance. In this study, four kinds different morphologies of α-Fe 2 O 3 - x (truncated hexagonal bipyramidal, cubic, hexagonal shape, and spherical) were synthesized by hydrothermal method , and a photocatalyst (H-α-Fe 2 O 3 - x ) with higher catalytic activity was prepared by hydrogenation. The results of UV–Vis DRS , PL , Raman, and XPS analysis , the oxygen vacancies and Fe (II) species were introduced into the α-Fe 2 O 3 catalyst after the hydrogenation reaction. The H-α-Fe 2 O 3 - x showed good degradation performance for TC and DX as EMPs model pollutants. The results show that the formation of oxygen vacancy and Fe 2+ is the main factor to improve the photocatalytic activity of the reaction system. Furthermore, the reaction mechanism revealed that reactive radicals involved in the H-α-Fe 2 O 3 - x photocatalytic system were •OH, •O 2 − , and h + responsible. This study provides an alternative technology for an easy and effective means for bandgap engineering to improve the photocatalytic performance of photocatalysts and facilitate widening environmental application.
研究领域:
环境科学
·
材料科学
·
化学
·
光催化
✓ 已验证
DOI
高影响因子
CHEMOSPHERE
·
2025
·
IF 8.1
Xinyao Wang,Zhiling Huang,Yue Meng,Bo Xie,Zheming Ni,Shengjie Xia
In this paper, ZnCdS/ZnCr-LDHs Z-scheme heterojunction containing zinc-oxygen bi-vacancy (V Zn + O ) were constructed and applied to photodegradation of norfloxacin (NOR) in water. A comprehensive investigation was conducted into the effects of concentration of V Zn in the composite, amount of catalyst, concentration of norfloxacin, temperature of the solution, and pH on the degradation activity. It comprehensively investigates the reaction kinetics, establishing a complete kinetic equation and determining the activation energy. Key parameters including catalyst dosage, pH, and reaction orders are systematically analyzed to elucidate their influence on the reaction process. The reaction mechanism of photodegradation of NOR is deeply analyzed from the perspectives of thermodynamics and kinetics. Z-scheme heterojunction not only facilitates the separation of photogenerated charges, but also preserves photogenerated electrons with strong reducing ability and photogenerated holes with high oxidizing ability; The existence of double vacancies not only provides more active sites for the material, but also regulates the band structure of the material, which contributes to the generation of free radicals. The synergistic effect of Z-scheme heterojunction and V Zn + O resulted in a removal rate of 89 % for NOR with a concentration of 20 mg/L after 90 min of visible light irradiation. In addition, based on ESR and XPS test results as well as DFT calculations, the synergistic mechanism of Z-scheme heterojunction and V Zn + O in the photodegradation process was analyzed in detail from the aspects of band structure, electron transfer, free radical species, and built-in electric field. The pathway of NOR photodegradation and the toxicity analysis of intermediate products were also provided.
研究领域:
环境科学
·
材料科学
·
化学工程
·
光化学
·
水处理技术
·
毒理学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
IONICS
·
2024
·
IF 2.4
Zheng Tingting,Wang Zhixing,Wang Siwu,Li Xinhai,Guo Huajun,Peng Wenjie,Wang Jiexi,Yan Guochun
Spinel LiMn 2 O 4 -based lithium-ion batteries are widely applied in electric two-wheeler and low-speed vehicles due to their low cost and low toxicity. Nevertheless, the Mn deposition at the anode originated from Mn dissolution of LiMn 2 O 4 causes a poor elevated temperature cycle life of graphite/LiMn 2 O 4 batteries. Herein, a graphite/LiFePO 4 cell with specific Mn 2+ added in the electrolyte is provided as an efficient evaluation method to research Mn 2+ deposition. Besides, an effective strategy by adding a ligand hexamethylenetetramine (HMTA) as an electrolyte additive is proposed to prevent Mn 2+ depositing. HMTA effectively “locks in” Mn 2+ through strong coordination, as confirmed by Raman spectroscopy and density functional theory (DFT) calculations. Moreover, the CV and XPS results indicate that the adsorption of HMTA is able to significantly inhibit side reactions at the anode/electrolyte interface. By adopting this strategy, the capacity retention of graphite/LiMn 2 O 4 cell is enhanced from 68.9% to 79.0% at 0.5 C after 100 cycles under 60 °C when adding 0.5% HMTA additive into the blank electrolyte. This work provides a new insight into revealing the mechanism of Mn 2+ regulation by introducing HMTA and improving the electrochemical performance of graphite/LiMn 2 O 4 batteries at elevated temperature.
研究领域:
材料科学
·
电化学
·
电池技术
✓ 已验证
产品关联
DOI
高影响因子
FIBERS AND POLYMERS
·
2024
·Vol. 25
·期 5
·1713-1725
·
IF 2.2
Tan Lei,Bai Xiuzhi,Yao Rui,Fu Zengjin,Wang Jing,Wang Yicheng,Lin Tingrui,Hao Yan,Yang Hui,Yang Huimin,Sai Huazheng
The biodegradable biomass adsorbent (cellulose- g -PSS) was synthesized in LiCl/ N, N -dimethyl acetamide by the free-radical grafting polymerization reaction between sodium styrene sulfonate (SSS) and cellulose. Systematic optimization was conducted on many reaction parameters, including reaction time, monomer dosage, and reaction temperature. The grafting yield of cellulose- g -PSS was 50.16%. The chemical structures, physical, and chemical characteristics of cellulose- g -PSS were characterized by FTIR, SEM, PZC, 1 H NMR, XRD, TGA and XPS. An assessment was conducted to determine the sorption of Ce (III) on cellulose- g -PSS by changing the contact time, adsorbent dosage, pH, initial Ce (III) concentration, and NaCl concentration. The process of adsorption rapidly reached a state of equilibrium within a time frame of 25 min and was well explained using pseudo-second-order kinetic and Langmuir isotherm model. The maximum adsorption capacity for Ce (III) obtained from the Langmuir isotherm model was 84.80 mg·g −1 . The impact of NaCl concentration on the sorption of Ce (III) and XPS analysis showed that Ce (III) ions were adsorbed onto cellulose- g -PSS through ion-exchange mechanism. As a whole, cellulose- g -PSS exhibited great potential in rare earth wastewater treatment.
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
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
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2021
·
IF 4.539
Ran Wang,Chong Cai,Di Wang,Zhiwei Liu,Lili Gao,Tifeng Jiao
In this work, a new type of self-assembled phytic acid-graphene oxide composite foam (PAGF) was prepared by hydrothermal method. In addition, Au nanoparticles (Au NPs) and Fe 3 O 4 particles were loaded onto PADF to obtain PAGF@Au&Fe 3 O 4 composite by a simple one-step method. The addition of graphene oxide (GO) can effectively prevent the agglomeration of Au NPs and weaken its surface passivation. The results of SEM, XRD, XPS and BET proved the successful preparation of the composite and its large specific surface area. Moreover, the synthesized PAGF@Au&Fe 3 O 4 composite showed good catalytic performance for p-nitrophenol (4-NP) and o-nitroaniline (2-NA) solutions with the rate constant (k) values of 0.0799 min −1 and 0.0546 min −1 , respectively. Due to the addition of Fe 3 O 4 , the composite exhibited good stability and recyclability, and maintained high catalytic efficiency after 8 cycles of catalytic process. The current work provides new ideas for developing novel graphene oxide-based composite materials and their catalytic degradation of organic pollutants.
研究领域:
材料科学
·
环境科学
·
纳米技术
·
催化
✓ 已验证
产品关联
DOI
高影响因子
FIBERS AND POLYMERS
·
2020
·Vol. 21
·期 6
·1229-1237
·
IF 1.797
Zhang Yiyi,Zhang Nan,Wang Qiang,Yu Yuanyuan,Wang Ping,Yuan Jiugang
Most modifications of wool focused on its surface due to the existence of the cuticle scales. For instance, chlorination, oxidation and protease treatments were used to break down or remove the scales. However, these modifications usually severely damaged the internal structure of wool. In this paper, a novel approach based on surface micro-dissolution was employed to modify the surface of wool to minimize the internal damage of wool, and improve the surface-related properties of wool. The micro-dissolution system used NaHSO 3 /urea to dissolve the scale layer of wool. After being micro-dissolved with NaHSO 3 /urea system, scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS), fluorescence microscopy, Fourier transform infrared spectroscopy (FTIR), and the Allwörden reaction were utilized to characterize the treated wool. Furthermore, felting shrinkage, strength loss and wettability of the treated wool were determined. The results showed that NaHSO 3 /urea system could dissolve the scale layer from outside to inside. The fluorescence microscopic images further indicated that low concentration of NaHSO 3 /urea system can dissolve the surface of wool without the serious damage of internal structure. Moreover, the micro-dissolution system can be controlled to dissolve the scale layer on the surface of wool slightly by adjusting the reaction conditions. The presented method is simple, easy to operate, and economical, thereby can open up new directions for the surface modification of wool.
研究领域:
材料科学
·
纺织工程
·
化学工程
✓ 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
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2023
·
IF 8.2
Xinyi Xing,Xian Shi,Mengya Ruan,Qichun Wei,Ying Guan,Hui Gao,Siquan Xu
Introduction of the sulfonic acid group into H-β zeolite to prepare β-SO 3 H bifunctional catalysts for the efficient synthesis of 5-hydroxymethylfurfural (HMF) from cellulose . Catalysts characterization, such as XRD, ICP-OES, SEM (Mapping), FTIR, XPS , N 2 adsorption-desorption isotherm, NH 3 -TPD, Py-FTIR demonstrate the sulfonic acid group was successfully grafted onto the β zeolite. A superior HMF yield (59.4 %) and cellulose conversion (89.4 %) was obtained in the H 2 O(NaCl)/THF biphasic system under 200 °C for 3 h with β-SO 3 H(3) zeolite as catalyst. More valuable, β-SO 3 H(3) zeolite converts other sugars and obtains ideal HMF yield, including fructose (95.5 %), glucose (86.5 %), sucrose (76.8 %), maltose (71.5 %), cellobiose (67.0 %), starch (68.1 %), glucan (64.4 %) and also converts plant material (25.1 % for moso bamboo and 18.7 % for wheat straw) with great HMF yield. β-SO 3 H(3) zeolite catalyst keeps an appreciable recyclability after 5 cycles. Moreover, in the presence of β-SO 3 H(3) zeolite catalyst, the by-products during the production of HMF from cellulose were detected, and the possible conversion pathway of cellulose to HMF was proposed. The β-SO 3 H bifunctional catalyst has excellent potential for the biorefinery of high value platform compound from carbohydrates.
研究领域:
催化
·
化学工程
·
材料科学
·
生物化学
·
可再生能源
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CERAMICS INTERNATIONAL
·
2023
·
IF 5.2
Lei Xiao,Qiang Li,Lianwen Deng,Sen Peng,Tulin Yi,Weichun Liu
Ba 1- x K x (Zn 1/3 Nb 2/3 )O 3- x /2 (BKZN, x = 0–0.2) ceramics were prepared by the high-temperature solid-state reaction method. Based on P–V–L theory, Raman vibration spectroscopy and X-ray photoelectron spectroscopy (XPS), this paper investigates the relationship between the internal and external factors of K + substitution in the Ba(Zn 1/3 Nb 2/3 )O 3 (BZN) ceramics and the microwave dielectric properties of the ceramics. X-ray diffraction (XRD) characterisation revealed that all samples were single phase with no impure phases. Replacing Ba 2+ with K + greatly reduced the sintering temperature and optimised the microwave dielectric properties of the ceramics. The dielectric constant ( ε r ) was closely related to the ion polarizability and density, and inversely proportional to Raman shift of the A 1g (O) peak. The quality factor ( Q × f ) depended largely on the lattice energy ( U b ) and the full width at half-maximum (FWHM) of A 1g (O) near 790 cm −1 . The temperature coefficient of the resonance frequency ( τ f ) could be inferred from the bond energy ( E b ) and oxygen octahedral distortion. Finally, outstanding microwave dielectric properties ( ε r = 40.83, Q × f = 71,658 GHz and τ f = 2.52 ppm/°C) were acquired for Ba 0.95 K 0.05 (Zn 1/3 Nb 2/3 )O 2.975 ceramics sintered at the optimum sintering temperature (1325 °C) for 4 h.
研究领域:
材料科学
·
陶瓷
·
微波介电材料
·
固态化学
·
光谱学
✓ 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）