Scientific Reports
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2020
·Vol. 10
·期 1
·1-12
·
IF 3.998
Chen Huayao,Chen Lishen,Shen Zhichuan,Zhou Hongjun,Hao Li,Xu Hua,Zhou Xinhua
Salicylaldimine, furfuralimine and benzaldehyde imine were adopted to modify mesoporous silica (MCM) respectively denoted as Sal-MCM, Fur-MCM and Ben-MCM before loading methyl eugenol (Me) for pesticide delivery. Me was adsorbed by Schiff base mesoporous silica without destructing regular hexagonal pore structure verified by the characterization results. DSC result implied that Me in amorphous state which was distributed in the pores of the mesoporous silica. The loading content of Me-Sal-MCM, Me-Fur-MCM and Me-Ben-MCM 67.89%, 73.34% and 73.84% which was higher than Me-MCM without modification (67.35%).Because the electrostatic interaction and π-π interaction between Schiff base and Me strengthened the adsorption capacity of the carrier. And the electrostatic interaction played a more important role in interaction between Me and Schiff base modified mesoporous silica. As a result, Schiff base modified sustained release system also has significantly longer sustained release time with a sequence of Me-Sal-MCM > Me-Ben-MCM > Me-Fur-MCM in release speed in negative correlation with the electric potential sequence. The behaviors of their sustained release performance can be fitted by First order kinetic model before Schiff base modification. After modification, their sustained release behaviors were consistent with Korsmeyer-Peppas equation with non-Fickian diffusion mechanism indicating that main impact on the release process after modification was no longer mainly controlled by the difference of the concentration. Finally, the highest lure rate of the modified MCM (Me-Fur-MCM) equals to the 73% of the pure Me due to its highest BET surface area and strongest interaction with Me among the three Schiff base modified samples. Therefore, the environment-friendly slow-release bio pesticide with long service life was prepared to reduce the damage on the environment caused by pesticide.
研究领域:
材料科学
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化学
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环境科学
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农业科学
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS
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2019
·
IF 3.47
Zhi Zheng,Jun Wang,Yi Wei,Xuejun Liu,Fengwen Yu,Jianbing Ji
La-Fe modified Si-MCM-41 (La-Fe/Si-MCM-41) catalysts were prepared by the wet impregnation method and used in catalytic cracking of soybean oil (CCS) for biofuel production. The catalysts were characterized by BET, XRD, XPS, Py-FTIR and CO 2 -TPD. The results showed that the aromatics content increased with the increase in B/L value, while the content of oxygenated compounds decreased, indicating that Brönsted acid sites were the major active sites for deoxygenation and aromatization reactions. Compared with Si-MCM-41, the Brönsted acidity of LFM-6 sharply decreased from 22.49 to 5.86 μmol g −1 . Accordingly, the aromatics content was reduced from 37.51 wt.% to 14.52 wt.% which was lower than the limitation (15 wt.%) according to the global environmental legislation. However, for the LFM-6 catalyst, the excessive loss of Brönsted acid sites and sharp decrease in BET surface area and pore volume led to the decrease in deoxygenation. As a result, the fatty acids content increased from 2.71 wt.% to 16.67 wt.% and the acid value reached 35.20 mgKOH g −1 . When the La-Fe loading increased to 15 wt.%, part of fatty acids were converted into ketones by the active sites on Fe 2 O 3 /La 2 O 3 and strong Lewis acid sites on catalysts. Besides, the new weak Lewis acid and basic sites on Fe 2 O 3 /La 2 O 3 exhibited the synergistic effect on promoting the generation of alkenes. The CaO/LFM-6 composite catalysts prepared by the mechanical mixing of LFM-6 and CaO were used in CCS to reduce the acid value of biofuel. LFM-6-C-3 was proved to be an effective catalyst for CCS to produce biofuel with low aromatics (12.31 wt.%) and fatty acids (2.76 wt.%) content.
研究领域:
催化
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生物燃料
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化学工程
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环境科学
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产品关联
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
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2013
·
IF 5.825
Xing Tang,Huawei Chen,Lei Hu,Weiwei Hao,Yong Sun,Xianhai Zeng,Lu Lin,Shijie Liu
A series of low-cost readily-assembled eco-friendly metal hydroxides were examined as catalysts in the synthesis of a novel platform molecule, γ-valerolactone (GVL), from biomass-derived ethyl levulinate (EL) via hydrogen transfer reaction. Among these catalysts, ZrO(OH) 2 · x H 2 O was found to be most active. EL conversion of 93.6% and GVL selectivity of 94.5% were achieved when 2-propanol was used as a hydrogen donor at 473 K with a reaction time of only 1 h. The complete reaction pathway and the probable main by-products for the conversion of EL to GVL were clearly deduced for the first time. The ZrO(OH) 2 · x H 2 O catalyst could be reused at least ten times without any significant loss of catalytic activity. Furthermore, characterizations were carried out on the fresh and spent ZrO(OH) 2 · x H 2 O catalysts with XRD, FT-IR, BET, TGA-DTA. Combined with the results of poisoning experiments, a plausible mechanism for catalytic transfer hydrogenation (CTH) of EL to GVL was proposed to be consisted of a catalytic cycle involving a six member ring transition state.
研究领域:
化学工程
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催化
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绿色化学
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可再生能源
✓ 已验证
产品关联
DOI
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
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2023
·
IF 9.8
Jiaqing Huang,Jing Ye,Wenhui Gao,Cenwei Liu,G.W. Price,Yanchun Li,Yixiang Wang
Pyrolytic biochar (PL-BC, pyrochar) and hydrothermal biochar (HT-BC, hydrochar) derived from branches and leaves of tea plants had different pH, electrical conductivity (EC), total carbon nitrogen content, BET surface area, total pore volume, average pore diameter, and functional groups. HT-BC had a larger specific surface area and more functional groups than PL-BC. Ralstonia Bcul-1 ( R -B) was the dominant and functional bacteria in a fertilized vegetable soil supplemented with TBB - immobilized R -B (TBB + R -B). R -B vitality was more closely related to BET surface area, total pore volume, and functional groups of tea-based biochar (TBB: PL-BC and HT-BC). R -B was able to maintain high oxidase activity. R -B and TBB + R -B can increase the activities of urease and peroxidase in vegetable soil playing an essential role in the biotransformation of ammonium nitrogen (NH 4 + -N) and nitrate nitrogen (NO 3 − -N). TBB was able to simultaneously increase the content of NO 3 − -N and NH 4 + -N, and TBB + R -B also significantly increased NO 3 − -N content but decreased NH 4 + -N content in a fertilized vegetable soil. These results indicated that R -B promoted nitrification in the soil, i.e. conversion of NH 4 + -N into NO 3 − -N, by enhancing the activities of urease and peroxidase. R -B had high adsorption capacity for cadmium (Cd) and chromium (Cr) (Cd&Cr: Cd and Cr). Moreover, TBB + R -B was able to convert weak acid extractable and reducible Cd&Cr into a more stable residual fraction and oxidizable Cd&Cr. The overall effect of the treatments was to reduce plant uptake of Cd&Cr by cabbage. TBB + R -B significantly promoted R -B growth, changed inorganic nitrogen speciation, increased NO 3 − -N supply, reduced Cd&Cr bioavailability, and decreased plant tissue Cd&Cr content.
研究领域:
环境科学
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土壤学
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微生物学
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农业
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DOI
PubMed
高影响因子
ENVIRONMENTAL RESEARCH
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2021
·
IF 6.498
Yanan Cai,Jing He
The release of Mn(II) occurs in the degradation of organic matters by manganese ore (MnO 2 ), resulting in a reduced efficiency. During the degradation of ciprofloxacin (CIP), in a biofilter, this paper put forward a novel method that similar to the geo-cycle of Mn (MnCS) on the Earth to regenerate MnO 2 . The freshly prepared MnO 2 was suitable for the use in the MnCS. It indicated that the mutual conversion between Mn(II), Mn(III), and Mn(IV) in the MnCS, which was driven by CIP and manganese oxidizing bacteria (MnOB), could maintain the activity of MnO 2 . The MnCS showed feasibility in the coexistence of ammonia or humic acid , and provided a kinetic degradation. The physicochemical features of MnO 2 before and after bio-regeneration were characterized by TEM , XRD, BET, and XPS. It was found that the morphological structure of MnO 2 became loose and the maximum peak of pore size distribution became smaller, but the increase of surface area, the change of Mn(III/IV) content, and the decrease of crystallinity favored the bio-regeneration process. Moreover, as a mediator in the MnCS, the group of MnOB was dramatically inhibited by CIP, and the bacterial community had changed significantly. The typical MnOB shared low abundance in the biofilter, while the rarely reported genera (e.g. Sphingomonas ) that related to the formation of Mn deposits appeared to be involved in the MnCS.
研究领域:
环境科学
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微生物学
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化学
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生物技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
MICROPOROUS AND MESOPOROUS MATERIALS
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2020
·
IF 4.551
Niu Liu,Jun Cheng,Wen Hou,Xiao Yang,Junhu Zhou
In order to form strengthened active sites for superior CO 2 adsorption on core shell ZIF-8@ZIF-67 nanocomposites , graphene oxide (GO) with oxygen-containing functional groups was used as support to synthesize hybrid adsorbents with unsaturated Zn–N 2 –O active sites. The results of XPS O 1s and FTIR analysis revealed that the Me–O functional group content in the 0.5 wt% graphene oxide (GO)-supported core shell ZIF-8@ZIF-67 nanocomposite (38.9 at.%) was much higher than that in the 0.5 wt% reduced graphene oxide (RGO)-supported nanocomposite (19.4 at.%). This was because hydroxyl functional groups in the GO formed coordination bonds with zinc atoms in core shell ZIF-8@ZIF-67. XPS N 1s spectra indicated that the incorporation of oxygen-containing functional groups in GO resulted in the transition of binding form from Me–N 4 to Me–N 2 . The CO 2 adsorption capacity of GO-supported core shell ZIF-8@ZIF-67 gradually decreased from 2.15 to 1.30 mmol/g as GO weight percentage increased from 0.5 to 4 wt%, which was consistent with the decrease in BET surface area from 1378 to 585 m 2 /g and increase in peak pore diameter from 7.7 to 8.2 Å. Density functional theory (DFT) calculations demonstrated that unsaturated Zn–N 2 –O active sites in GO-supported core shell ZIF-8@ZIF-67 nanocomposites resulted in a decreased O C⋯Zn interaction distance from 4.65 (Zn–N 4 sites in core shell ZIF-8@ZIF-67) to 3.46 Å and an increased binding energy from 34.02 to 38.87 kJ/mol. Therefore, 0.5 wt% GO-supported core shell ZIF-8@ZIF-67 nanocomposites exhibited the highest CO 2 adsorption capacity of 2.15 mmol/g (at 273 K and 1 bar), 1.34 times higher than that of core-shell ZIF-8@ZIF-67.
研究领域:
材料科学
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环境科学
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化学
✓ 已验证
产品关联
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2021
·Vol. 45
·期 32
·14406-14413
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IF 3.591
Yubo Liu,Guoqiang Ding,Guoping Zhao,Haohao She,Yulei Zhu,Yong Yang
Combining glucose dehydration and the subsequent hydrogenation in one pot is a preferable approach for process development as such a method allows in situ generation of the reactive intermediate to undergo further reaction without extra energy-intensive separation. Herein, phosphotungstic acid and various types of titania (anatase, rutile, P25) supported Ru-based catalysts were considered as the dehydration and hydrogenation catalysts, respectively. Modulating the different reactant media (N2, H2), various products were obtained with GBL–H2O as the solvent. A considerable yield (42%) of levulinic acid (LA) and γ-valerolactone (GVL) (40%) were obtained in nitrogen and subsequent hydrogen. Ru/TiO2 (rutile) was the favorable hydrogenation catalyst among the three types of Ru/TiO2. Meanwhile, a certain amount of sorbitol (36%) was obtained in pure hydrogen. The hydrogenation of glucose is more likely to occur than the glucose dehydration. The physicochemical properties of the catalysts were characterized by XRD, BET, TPR, STEM and in situ CO/FT-IR, and the results show that well-dispersed Ru particles are located on the rutile crystallites, which facilitated the hydrogenation of LA. A strong metal support interaction (SMSI) was responsible for the various microstructure properties and the different hydrogenation reactivity. This work allows a better understanding of the reaction paths of glucose conversion.
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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产品关联
DOI
高影响因子
NORDIC PULP & PAPER RESEARCH JOURNAL
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2021
·Vol. 36
·期 1
·21-32
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IF 1.04
Guozheng Chen,Jinquan Wan,Yongwen Ma,Yan Wang
The macroscopic and microscopic properties of old newsprint pulp with xylanase, MLac/Glu (modified laccase-glutamate system), and X-MLac/Glu (xylanase synergistic modified laccase-glutamate system) pretreatment was investigated by means of fiber quality measurements (FQA), attenuated total reflectance-infrared spectroscopy (ATR-IR), headspace gas chromatography (HSGC), X-ray diffract ion method (XRD), Low-temperature nitrogen absorption and scanning electron microscopy (SEM). Results showed that, compare with the control pulp, the brightness and lightness (
L
∗
) of hydrogen peroxide bleached pulp after X-MLac/Glu pretreatment increased by 5.86 % ISO and 3.58 %, respectively. FQA analysis revealed that coarseness and fine fiber content increased slightly. The content of carboxyl groups and water retention value increased remarkably by 31.11 % and 39.22 %, respectively. The paper physical analysis showed that the paper strength properties have improved significantly. The crystallinity of cellulose decreased by 3.82 % due to X-MLac/Glu pretreatment. ATR-IR analysis indicated some non-cellulose components are removed. The BJH average pore size and BET specific surface area increased after enzyme pretreatment. The SEM analysis showed that through X-MLac/Glu treatment the fiber surface becomes rough and the connections between the fibers become tighter, more fibrils appeared.
研究领域:
制浆造纸科学
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生物技术
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材料科学
✓ 已验证
DOI
高影响因子
CHEMOSPHERE
·
2021
·
IF 7.086
Yanan Yang,Yu Zhang,Hong Zheng,Baichao Zhang,Qi Zuo,Kaiyue Fan
A key challenge in trace heavy metals removal from drinking water by adsorption technology is to achieve high adsorption capacity and rapid uptake speed of adsorbent. Herein, we report a functionalized double modified covalent organic framework (DMTD–COF–SH) bearing high-density sulfur and nitrogen chelating groups provided simultaneously by 2,5-dimercapto-1,3,4-thiadiazole (DMTD) and 1,2-ethanedithiol, which was prepared via a facile one-pot thiol-ene “click” reaction. PXRD , FTIR, XPS, SEM, BET and 13 C MAS NMR confirmed their successful graft, and DMTD was found to be more easily grafted on the COF surface layer than 1,2-ethanedithiol. The as-prepared DMTD–COF–SH showed remarkable adsorption capacity and ultrafast uptake dynamics to trace heavy metals owing to the synergistic effects resulting from densely populated sulfur and nitrogen chelating groups within ordered COF mesopores and at the COF surface. On the basis of the drinking water treatment units standard NSF/ANSI 53–2020, when the adsorbent dosage was 10 mg/30 mL and 20 mg L −1 calcium ions coexisted, the lead concentration decreased from initial 150 μg L −1 to 2.89 μg L −1 within 10 s, far below the allowable limit of world health organization (WHO) drinking water standard (10 μg L −1 ), and the maximum adsorption capacity meeting the standard attained 14.22 mg g −1 . The adsorbent also exhibited excellent stability, wide applicable pH range and outstanding adsorption performance for coexisting trace lead, mercury, cadmium, chromium (VI) and copper in tap water, indicating that the DMTD–COF–SH material has excellent application prospect for trace heavy metals removal from drinking water.
研究领域:
环境科学
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材料科学
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水处理
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化学工程
✓ 已验证
DOI
高影响因子
SYNTHETIC METALS
·
2021
·
IF 3.266
Adeel Ahmed,Muhammad Usman,Song Wang,Bing Yu,Youqing Shen,Hailin Cong
The increasing worldwide pollution of water resources with dyes has emphasized the need to develop highly versatile and effective approaches for their remediation. In this study, zirconium substituted manganese cobalt ferrite (Mn 0.2 Co 0.8 Zr x Fe 2−x O 4 ) nanoparticles , and their composites with reduced graphene oxide (Mn 0.2 Co 0.8 Zr x Fe 2−x O 4 /rGO) were synthesized and used as effective photocatalyst materials for the degradation of dyes. X-ray diffraction analysis was executed to probe the cubic spinel structures of nanoparticles in the size range of 18–24 nm. Scanning Electron Microscopy revealed the formation of spherical shaped nanoparticles and their dispersion on the exfoliated surface of rGO. The saturation magnetization and remanence of samples decreased from 57.23 to 24.16 emu/g and 27.68–13.98 emu/g respectively while the coercivity of samples increased from 1067.76 Oe to 1616.97 Oe due to the incorporation of non-magnetic Zr 4+ into the lattice. The BET surface area of nanoparticles and nanocomposites lies in the range of 47.52–78.33 m 2 /g, while the average pore size was found to be 2.48–21.43 nm. The degradation performance of as-prepared nanoparticles and nanocomposites was evaluated against Alizarin Yellow R (AYR) dye under visible light irradiation. Mn 0.2 Co 0.8 Zr x Fe 2−x O 4 /rGO nanocomposites showed higher degradation performance and 92.49% dye degradation was achieved in 70 min, while in the case of Mn 0.2 Co 0.8 Zr x Fe 2−x O 4 nanoparticles 52.45% dye was degraded in 120 min. The effects of different operational parameters on the degradation performance of nanocomposites were investigated thoroughly. The higher photodegradation of nanocomposites was attributed to the large surface area and less magnetization, making them potential candidates for their applications in water purification.
研究领域:
材料科学
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环境科学
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纳米技术
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光催化
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
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2021
·
IF 19.503
Hengli Qian,Guanjie Yu,Qidong Hou,Yifan Nie,Chuanyunlong Bai,Xinyu Bai,Haozhi Wang,Meiting Ju
To achieve efficient degradation of pharmaceutical and personal care products (PPCPs), dual reaction centers [email protected] photo-Fenton catalysts with high-speed electron transmission channel were designed through surface hydroxyl-induced assembly. In [email protected] catalytic system, the photocatalysis center of ZnO and Fenton catalytic center of FePc were formed simultaneously. Concept and process for the control of hydroxyl groups to construct a dual reaction center [email protected] photo-Fenton catalyst were verified ingeniously based on the density functional theory (DFT) analysis and experimental results. A series of catalysts, including ZIF-8 (400 ℃-N 2 ), FePc (400 ℃-N 2 ), ZIF-8 (400 ℃)-FePc (400 ℃) and [email protected] were prepared and characterized by XRD, FTIR, TEM, BET, XPS, PL and DRS, respectively. The [email protected] catalyst showed superior performance for the photo-Fenton degradation of ibuprofen, affording degradation rate larger than 90 % within just 10 min under simulateed sunlight. The excellent performance of [email protected] catalyst is mainly attributed to the synergistic effect between dual reaction centers of [email protected] This work provides a novel method to construct dual reaction centers [email protected] catalyst with efficient photo-generated electrons transmission link and to strengthen the synergistic effect of dual reaction centers.
研究领域:
环境化学
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催化
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材料科学
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光化学
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产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2020
·
IF 8.758
Yangwen Liu,Qiao Liu,Lin Wang,Xianfeng Yang,Weiyou Yang,Jinju Zheng,Huilin Hou
Hollow carbon nanofibers with hierarchical porous shells were prepared by NaOH activation of the electrospinning SiCNO fibers, followed by carbonization treatment. By adjusting the carbonization temperature, porous hollow carbon nanofibers with different Brunauer–Emmett–Teller (BET) specific surface areas and total pore volumes are obtained, both of which are explored as electrode materials for supercapacitors. It was found that the obtained products (HCF800) possess the highest BET specific surface area of 2628.10 m2/g and the largest pore volume of 2.32 cm3/g when the carbonized temperature was designed at 800 °C, thus displaying the best supercapacitor performance. The electrochemical results in a three-electrode system show that HCF800 exhibits a high specific capacitance of 330.11 F/g as the discharge current density is 1 A/g and still maintains 65.3% of its original specific capacitance when the current density reaches 20 A/g. Moreover, in a two-electrode system, HCF800 also exhibits an excellent specific capacity of 259.86 F/g at a current density of 1 A/g, marvelous cyclic stability with the specific capacitance retention of 95.3% even after 10,000 cycles, and a large energy density of 12.99 W h/kg at 1.0 A/g. Significantly, the supercapacitor performance of these porous hollow carbon nanofibers is also superior to that of many previously reported carbon materials, which proved them to be worthy candidates for high-performance electrode materials.
研究领域:
材料科学
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电化学
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纳米技术
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能源存储
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）