CHEMICAL ENGINEERING JOURNAL
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2022
·
IF 16.744
Ye Meng,Yumei Jian,Jie Li,Hongguo Wu,Heng Zhang,Shunmugavel Saravanamurugan,Song Yang,Hu Li
The appropriate regulation of photocatalyst band structure by simultaneous introduction of active sites is an effective strategy in constructing efficient photocatalytic systems for biomass valorization. Herein, a renewed host–guest photocatalyst (Ov-WO 3 @CB[5]) prepared by anchoring cucurbit[5]uril on oxygen vacancy-rich WO 3 was efficient for reductive upgrading of biomass derivatives using NH 3 -BH 3 , such as cascade photocatalytic hydrogenation-cyclization of ethyl levulinate to γ-valerolactone (up to 99 % yield) at 25 °C in 1 h, and quantitative production of primary/secondary bio-alcohols or arylamines from various aldehydes/ketones or nitroarenes, respectively. Also, the rate of H 2 production by direct photocatalytic hydrolysis of NH 3 -BH 3 could reach 5.75 mL h −1 g −1 . The inclusion of cucurbit[5]uril effectively adjusted the semiconductor band structure and enhanced migration efficiency of photo-generated carriers, and the hydrophobic cavity of cucurbit[5]uril favored the entrance of NH 3 -BH 3 , as elaborated by theoretical calculations. Properly engineering supramolecular surface-active sites based on interface host–guest chemistry opens new avenues for reductive upgrading of biomass and hydrogen evolution.
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FUEL
·
2022
·
IF 8.035
Xiaofeng Zhang,Hengfei Zhang,Bo Qiu,Dandan Zhu,Sheng Zhang,Yunpeng Bian,Junhong Wang,Dajian Li,Shimin Wang,Wenpeng Mai,Jian Chen,Tao Li
The conversion of CO 2 cycloaddition to value-added cyclic carbonates is of considerable interest owing to the renewable greenhouse gas and 100 % atomic economy. However, it is still a big challenge to develop low-cost and high-efficient catalysts. Here, we report a facile design way, in a single step, for the creation of robust catalytic nanoreactors for heterogeneous catalyst in the cycloaddition of CO 2 to cyclic carbonates. The Al(III) - porphyrin-based porous organic polymer catalysts exhibited remarkably high efficiency for propylene carbonate with turnover frequencies of up to 443.6 h −1 at room temperature and atmospheric pressure without solvent, which notably surpasses most previously reported heterogeneous catalysts and relevant homogeneous catalysts. Even using dilute CO 2 (15 % CO 2 in N 2 ), a TOF up to 27.0 h −1 could be afforded under ambient conditions (25 °C, 1 bar) by Al-Por-POP-2, which showed high stability for recyclability up to 10 times without a significant decrease. These studies provided a simple and efficient synthetic strategy in favor of mass production and future industrial application for the cycloaddition of CO 2 with low cost and high efficiency.
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Frontiers in Bioengineering and Biotechnology
·
2022
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IF 6.064
Yang Guangxu,Gong Zhenggang,Luo Xiaolin,Shuai Li
Lignin structural analysis is important for the comprehensive utilization of lignin as well as delignification and bleaching during pulping while it is difficult to completely elucidate lignin structure due to its structural complexity and heterogeneity. Depolymerization of lignin into simple monomers via alkaline cupric oxide oxidation (OxCuO) followed by chromatographic analysis of the monomers is an effective method for lignin structural analysis. Here we revisited the OxCuO of lignin model compounds (monomers and dimers) and three representative lignocelluloses (i.e., Eucalyptus, Masson pine, and corn stover) to understand the effects of reaction conditions and lignin sub-structures on oxidation product yields and distributions. The improved OxCuO was found to be effective in oxidatively breaking the robust interunit C-C bonds in the β-β′ and β-5′ moieties of lignin other than β-O-4′ linkages at an elevated temperature (210°C). Further degradation of the monomeric oxidation products could also occur to reduce the monomer yields under a severe condition (i.e., high temperature and long reaction time). In addition, O2 inputs could reduce the monomer yields via nonselective overoxidation, thus having negative effects on accurate structural analysis of lignin. The O2 removal via ultrasonication combined with N2 flushing prior to the oxidation reaction could improve the monomer yield about 1.2 times (compared to that without O2 removal) at a low biomass loading of 5 wt%. By using the improved method of OxCuO, a monomer yield of 71.9% could be achieved from Eucalyptus (hardwood) lignin, which was much higher than conventional nitrobenzene oxidation (59.8%) and reductive depolymerization (51.9%). Considering the low cost, high availability, and low toxicity of CuO, the improved OxCuO could be a convenient and economic method for more accurate lignin structural analysis.
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高影响因子
CHEMOSPHERE
·
2022
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IF 8.943
Haiying Gao,Hui Yu,Jun Yu,Tianhui Xu,Yiming Feng,Yan Wang,Jun Qian,Chaoqun Tan
An origin Fenton-like system was discussed for the abatement of refractory contaminants. Sodium percarbonate (SPC) was utilized as the source of H 2 O 2 and crystal boron ( C -boron) was applied to enhance the activation of H 2 O 2 . Under the conditions of 0.50 mM Fe 3+ , 0.34 mM SPC, and heterogeneous catalysis using 100 mg L −1 C -boron, four target pollutants, at the initial concentrations of 20 μM, could be efficiently degraded by the Fenton-like system, with a degradation rate within 20 min up to 81.1% (aspirin, ASA), 92.8% (nitrobenzene, NB), 94.7% (flunixin meglumine, FMME), and 94.3% (benzoic acid, BA) respectively and total organic carbon removal up to 25.0%. The increase of Fe 2+ concentration indicated that the conversion of Fe 2+ /Fe 3+ was remarkably promoted by C -boron. Degradation reactions at acidic pH were comparatively fast, with pH-dependent k obs of 9.9 × 10 −2 min −1 (ASA), 1.5 × 10 −1 min −1 (NB), 1.7 × 10 −1 min −1 (FMME), and 1.9 × 10 −1 min −1 (BA), whereas those at neutral and alkaline pH were slower. Furthermore, reactive oxygen species including · OH, 1 O 2 , and O 2 · − were identified by in-situ electron paramagnetic resonance tests. The contribution ratios of · OH turned out to be about 71.3–86.7% for the decomposition of four contaminants. The elimination of natural organic matter and the performance of material recycling highlighted the potential for its application in water treatment . The inhibition rate of Chlorella pyrenoidosa reached 211.9% in the C -boron/Fe 3+ /SPC system. The relatively high algae toxicity limited its application scope, which requires additional research to resolve.
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Nano Research
·
2022
·Vol. 16
·期 4
·5880-5886
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IF 10.269
Tian Zhengbin,Deng Xiaohui,He Ping,Wang Guang-Hui
Monolithic catalysts play a crucial role in various catalytic applications, e.g., chemical synthesis, energy conversion, and environmental treatment, but their catalytic efficiency is often limited by the restricted mass transfer and insufficient exposure of active sites. Herein, we present a dual-templating strategy to fabricate atomic Pt dispersed on monolithic N-doped mesoporous carbon nanowires (Pt 1 /NMCW) with abundant super-/macropores, which, as monolithic catalyst, exhibits high catalytic performance in hydrogenation of 4-nitrophenol (4-NP). During synthesis, triblock copolymer (Pluronic F127) is employed as a primary soft template to generate the mesoporous structured carbon nanowires to improve the accessibility of Pt single sites; KCl crystallite is used as a secondary hard template to create the super-/macropores, which are beneficial for enhancing the mass transfer efficiency. Thanks to the dual-templating strategy that creates the monolithic carbon nanowires with hierarchically porous structure, the obtained Pt 1 /NMCW shows highly enhanced catalytic activity in 4-NP hydrogenation, outperforming its analogue synthesized without using KCl as template and being comparable to the nano-powder catalyst (i.e., atomic Pt loaded on the N-doped carbon nanospheres, Pt 1 /NCS).
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MICROCHIMICA ACTA
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2022
·Vol. 189
·期 10
·1-12
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IF 6.408
Liao Linhong,Tong Simiao,Luo Xiaogang,Liu Genyan,Wu Fengshou
A new iron porphyrin-based organic polymer (Fe-POP) was synthesized through the William ether reaction. The as-prepared Fe-POP presented high chemical stability, wide pore distribution, high iron content, and strong affinity with 3,3’,5,5’-tetramethylbenzidine (TMB) and hydrogen peroxide (H 2 O 2 ), which contributed to its excellent peroxidase-mimicking performance. In the presence of H 2 O 2 , Fe-POP could catalyze the transparent TMB into blue ox-TMB, which could be easily distinguished by the naked eyes. Moreover, glutathione (GSH) and ascorbic acid (AA) could convert blue ox-TMB into colorless TMB due to the inhibitory effect of GSH/AA to the catalytic oxidation of TMB. Based on this phenomenon, a rapid and sensitive colorimetric method for the assay of H 2 O 2 , GSH, and AA was developed using Fe-POP as sensor. The detection limits of H 2 O 2 , GSH, and AA were 1.37, 0.44, and 0.33 μM, respectively. Finally, the colorimetric method based on Fe-POP was used to evaluate the GSH and AA content in real samples, which provided the guidance for GSH and AA supplements in our daily diet, suggesting the significant potential of Fe-POP in practical applications. Graphical abstract
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ENVIRONMENTAL POLLUTION
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2022
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IF 9.988
Yao Tang,Jibo Dou,Zhijiang Lu,Jianming Xu,Yan He
The sluggish Fe 3+ /Fe 2+ cycle was the rate-limiting step in the Fenton-like reaction, and metal-free carbonaceous materials are considered as emerging alternatives to solve this problem. However, the effect of carbon material properties on the distribution of reactive species remains poorly understood. This study investigated the possibility and mechanism of using biochar to accelerate the Fe 3+ /Fe 2+ cycle to overcome the low efficiency of Fe 3+ /persulfate (PS) catalytic oxidation of phenanthrene . More importantly, the contribution of reactive species in the reaction systems with the variation of biochar pyrolysis temperatures was quantitatively studied. The results showed that medium-temperature derived biochar (BC500) had the greatest ability to enhance the Fenton-like system compared to the low- and high-temperature (BC350/700), and the first-order rate constant achieved 5.2 and 35.7-fold increase against the biochar/PS and Fe 3+ /PS systems, respectively. Using electrochemical evidence, sulfoxide probe tests, and steady-state concentration calculations, radicals yields were found to rise and then reduce with decreasing pyrolysis temperature, while the nonradical contribution of Fe(IV) increased to 56.3%. Electron paramagnetic resonance, Boehm titration, and Raman spectroscopy unraveled that the enhanced effect of biochar resulted from itself persistent free radicals, phenolic-OH, and edge defects, which enabled electron transfer between Fe 3+ and biochar. Fe 2+ was thus continuously generated and effectively activated the PS. This work enables a better understanding of the Fe 3+ -mediated Fenton-like reaction in the presence of biochar and provides a sustainable green strategy for Fenton chemistry with potential applications.
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JOURNAL OF RARE EARTHS
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2022
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IF 4.632
Shu Xie,Fei Li,Fengyi Liu,Quanqing Xu,Xufeng Zhang
Luminescent hydrogels have received considerable attention in the application of sensors . Nitroaromatics are harmful to human health and can be carcinogenic . Some skin allergies and central nervous system injuries may also be attributed to the over exposure to nitroaromatics. Thus, nitroaromatics sensor with fast detection and low detection limit is highly desirable. Herein, novel tough hydrogels were prepared by introducing hydrogen bonds and covalent bonds into the interpenetrating networks of modified chitosan and poly(vinyl alcohol) (PVA) via frozen-thawing induced chemical cross-linking. The synthesized hydrogels exhibit high mechanical strength (0.23 MPa tensile strength at 140% tensile strain , 1.0 MPa compressive strength at 80% compressive strain). Strong green emission was realized by energy transfer from the modified chitosan to Tb 3+ via the so-called “antenna effect.” The prepared luminescent hydrogels show an excellent detection effect on nitroaromatic compounds and its detection limit can reach ppm-level. The hydrogels also exhibit good reversibility and a fast “off–on” fluorescence switching process. This work may open up a new way for the development of stable, rapid, and reusable sensors for the detection of harmful nitroaromatics.
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WATER RESEARCH
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2022
·
IF 13.4
Xiaoyang Li,Ruolin Lv,Weiming Zhang,Mingyang Li,Junhe Lu,Yi Ren,Yue Yin,Jiahang Liu
Application of heterogeneous advanced oxidation processes (AOPs) for wastewater treatment suffers from the low oxidant utilization efficiency, slow catalytic cycling and severe matrix interference. Herein, we report that amorphous zirconium dioxide (aZrO 2 ), a redox-inert metal oxide, can efficiently activate peroxymonosulfate (PMS) to degrade organic micropollutants under very low oxidant doses and complex coexisting matrices. Distinct from conventional AOPs where radicals are formed, the surface Zr(IV)-PMS* complex was identified as the principal reactive species, and primarily conducted oxygen-atom-transfer route with selected molecules. Quantitative structure-activity relationship analysis indicated that the formation of Zr(IV)-PMS* complex was governed by the density of the surface hydroxyl groups. The strong interaction between the Zr atom and PMS caused the deviation of the negative charge from Zr(IV) metal sites to the oxidant. As a result, the O-O bond of the adsorbed PMS was prolonged and its oxidation potential elevated, which enabled it to directly react with contaminants. This study indicates the potential of aZrO 2 as a novel and eco-friendly catalyst that activates PMS to selectively tackle organic contaminants, and sheds light on the designing of Fenton-like catalysts using redox-inert metals.
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JOURNAL OF HAZARDOUS MATERIALS
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2022
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IF 14.224
Zijin Liu,Xianbo Sun,Jie Fu,Wen Liu,Zhengqing Cai
Polycyclic aromatic hydrocarbons (PAHs) are frequently released in aqueous phase by oil spill or from other sources, and photochemical oxidation is one of their major weathering processes. In this study, the photochemical behavior of phenanthrene (PHE, as a representative PAH) were studied and the effects of nitrogenous compounds were evaluated. The results showed that nitrate was an effective photosensitizer for improving the photodegradation of PHE, but the promoting effect was less effective in seawater due to the presence of halogen ions; the ammonia played a negligible role on PHE degradation. The photochemical ionization was a key process for PHE degradation, it can be retarded due to the quenching of triplet excited state by dissolved oxygen, and the inhibition was most prominent in fresh water. The presence of nitrate increased the steady state concentration of •OH from 2.08 × 10 −15 M to 1.04 × 10 −14 M in fresh water, and from 1.5 × 10 −16 M to 2.08 × 10 −15 M in seawater. The secondary-order reaction rate constant between PHE and •OH ( k • OH , PHE ) was determined as 5.70 × 10 9 M −1 s −1 . Similar trend was observed for 1 O 2 . The contribution of •OH to PHE removal was more prominent in fresh water than in seawater due to the quenching effects of halogen, and the increasing of nitrate enlarged the contribution of •OH. Two possible PHE degradation pathways were proposed based on GC-MS analysis and DFT calculation. The Quantitative Structure-activity Relationship (QSAR) evaluation showed that some degradation intermediates were more toxic than PHE, but the total environmental risk was still diminished due to the low percentage of toxic intermediates. This study provided theoretical and experimental insights into the influence of nitrogenous compounds on the photodegradation of PHAs in water environment.
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NEW JOURNAL OF CHEMISTRY
·
2022
·Vol. 46
·期 43
·20699-20710
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IF 3.925
Die Wang,Luminita Marin,Xinjian Cheng
Nitro compounds are widely used in modern industries. Among them, 2, 4-dinitrophenylhydrazine (DNH) is extremely harmful. It is of great significance to develop methods for the detection of DNH. In this work, chitosan was used as the substrate material, and fluoroborondipyrrole (BODIPY) was used as the fluorophore. Chitosan was endowed with the fluorescence sensing ability by the introduction of BODIPY units. First, BODIPY derivatives (NO-3 and BO-1) with an alkynyl group (CC) were synthesized. Second, small molecules NO-4 and BO-2 with an aldehyde group (–CHO) were obtained. Finally, the –NH2 groups on chitosan underwent a click reaction (–NH2/CC) and a Schiff base formation reaction occurred (–NH2/–CHO) to form three polymer probes C1, C2 and C3. CC formed in the click reaction can interact with DNH and can be used as recognizing sites for DNH. These chitosan probes have good thermal stability and could selectively recognize DNH, showing notable fluorescence quenching effects, which are visible to the naked eye. DNH is a typical electron-deficient compound, and the polymer fluorescent probe contains electron-rich groups, which makes it easier for the two species to combine and cause fluorescence changes. C1 is flexibly cross-linked, C3 is rigidly cross-linked, and C2 has a non-crosslinked structure, and they show different rheological properties. This work expands the application of chitosan.
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SEPARATION AND PURIFICATION TECHNOLOGY
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2022
·
IF 9.136
Chaoqun Tan,Wangqi Yu,Hong Mei,Kaiyang Chen,Tianhui Xu,Huiming Xiang,Yiming Feng,Lin Deng
In this study, Fe(III) catalyzed calcium peroxide (CaO 2 , CP) Fenton-like process assisted by crystal boron (C-boron) was applied for in situ chemical oxidation. Flunixin meglumine (FMME), aspirin (ASA), nitrobenzene (NB) and benzoic acid (BA) were selected as target contaminants. Pollutants decomposition by the CP/Fe(III) and C-boron/CP/Fe(III) systems was proposed in terms of diverse parameters, including C-boron dosage, pH, and temperature, with regard to the pseudo-first-order kinetic model (R 2 > 0.95). About 26.8% of 20 μM FMME was removed by 0.5 mM CP and 0.5 mM Fe(III) after 20 min at pH 4.0, whereas 90.4% of FMME was decomposed in the C-boron/CP/Fe(III) system with 100 mg/L C-boron. The removal rates of the other three pollutants were also improved to varying degrees. The k obs of the C-boron/CP/Fe(III) system for these four pollutants degradation at pH 4.0 was approximately 4.1 ∼ 5.3 times higher compared to the CP/Fe(III) system. Electron paramagnetic resonance and quenching experiments indicated that OH, O 2 − and 1 O 2 were present in both systems and contribution of OH was 71.3% at initial pH 4.0 in C-boron/CP/Fe(III) system, suggesting that it was the main reactive oxygen species for the contaminants elimination. Furthermore, experiments on the characterization of C-boron showed great reactivity and stability. This work manifested the promotion mechanism of pollutant degradation in the C-boron/CP/Fe(III) system.
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