CHEMICAL ENGINEERING JOURNAL
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2022
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IF 16.744
Xinfang Zhang,Yoav Eichen,Zhenwei Miao,Shuangkun Zhang,Qing Cai,Wei Liu,Jingbo Zhao,Zhanpeng Wu
Novel polyimine vitrimers were constructed from cyclophosphazene bearing three aldehyde groups, CP-3AP, terephthalaldehyde, TPA, and diaminodiphenyl methane, MDA. Owing to the incorporation of phosphazene skeleton and high content of aromatic ring structure, the new vitrimers exhibit superior flame retardancy with UL-94 V0 level and high limiting oxygen index, LOI, of ∼ 40%, high thermostability with T 5% (5% weight loss) of ∼ 420 °C and ∼ 75% residues at 800 °C. Vitrimers owned high Tg of ca 146 °C, robust tensile strength of ∼ 56 MPa and excellent reprocessability with greater than 90% recycling efficiency of mechanical properties even when subjected to three recycling cycles based on imine dynamic covalent bond. Additionally, possible bond exchange mechanisms that are involved in the processability were systematically researched by model compounds using TOF-mass spectroscopy. CP-3AP could be recovered by acidolysis with high 81% efficiency. Such excellent comprehensive properties of phosphazene based polyimine vitrimers open new routes to a variety of high-performance vitrimers, especially in terms of thermal and flame retardancy properties.
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APPLIED CATALYSIS B-ENVIRONMENTAL
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2022
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IF 24.319
Zhendong Zhao,Wenjun Zhou,Daohui Lin,Lizhong Zhu,Baoshan Xing,Zhiqi Liu
High metal loading of single-atom catalysts enables excellent catalytic activity, but possibly causes serious aggregation problem. Herein, a series of diatomic FeCo−N/C-x (x represents metal content) were skillfully designed and applied to improve the catalytic activity for peroxymonosulfate (PMS) activation toward degrading organic micropollutants. The unprecedented dual active sites, referring to Fe(N 3 )−Co(N 3 ) moiety and FeCo alloy, are constructed on the obtained FeCo−N/C-x, thereby exhibiting significantly greater performance toward degrading aqueous phenol (e.g., 0.316 min −1 for FeCo−N/C-3) via PMS activation, compared with those of traditional single-atom Co−N/C (0.011 min −1 ) and Fe−N/C (0.018 min −1 ). Combined experimental and theoretical calculations demonstrate the independent functions of dual active sites, in which Fe(N 3 )−Co(N 3 ) and FeCo alloy can decrease the energy barrier of O−O bond cleaving resulting in the formation of high-valent FeCo O reactive species and singlet oxygen, respectively. This study opens up a new platform toward constructing dual active sites for enhanced Fenton-like catalytic activity.
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ELECTROCHIMICA ACTA
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2022
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IF 7.336
Xuedong Du,Pei Su,Wenyang Fu,Qizhan Zhang,Minghua Zhou
To improve the mineralization efficiency of heterogeneous electro-Fenton (Hetero-EF), ultraviolet (UV) process and Hetero-EF process were coupled (Hetero-PEF) for degradation of sulfamethazine (SMT) by FeCu@PC (porous carbon) derived from metal-organic frameworks (MOFs). At 60 min, the total organic carbon (TOC) removal and mineralization current efficiency (MCE) of the Hetero-PEF process was 73.3% and 58.7%, which were both 2.23 times that of the Hetero-EF process due to the photoelectric synergy. Moreover, the Hetero-PEF process had wider pH applicability (3.0–7.0) than the Hetero-EF process. This process could also efficiently remove phenol , carbamazepine and 2, 4-D. Through process comparison, quenching and electron paramagnetic resonance (EPR) tests, the reasons for the improvement of mineralization efficiency by Hetero-EF process were disclosed, in which UV not only activated H 2 O 2 to produce • OH but also excited FeCu@PC to form photo-generated electrons to catalyze H 2 O 2 or O 2 to • OH and O 2 • − , respectively. In addition, UV excitation of Fe(OH) 2+ and Fe(OOCR) 2+ promoted the regeneration of Fe 2+ , which also greatly enhanced the H 2 O 2 conversion efficiency and mineralization current efficiency. In the five cycles of experiments, the removal efficiency of SMT still reached 97.0%. The FeCu@PC/Hetero-PEF process had the application prospect of highly effective removal of organic pollutants in water treatment.
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INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
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2022
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IF 8.025
Xinyu Lu,Xiaoli Gu
In this study, lignin-based epoxy resins (EP) were fabricated using lignin, phenol and glyoxal as crosslinking reagents. For improving the flame retardancy, a bi-DOPO compound with bi-hydroxyl structure was successfully synthesized, containing excellent quenching and charring capacities. Good pyrolysis behaviors of as-synthesized flame retardant resulted in significant quenching effect via structure decomposition to release PO and PO 2 free radicals for capturing reactive H and OH radicals produced from epoxy combustion. With addition of 0.18 wt% phosphorus, epoxy composite (10% LPG-ER-4) passed V-0 rating with high limited oxygen index (LOI) value of 35.2%. Cone calorimeter tests showed that heat release (including heat release rate (HRR) and total heat release (THR)) from combustion was reduced with assistance of flame retardant. Char residue analyses illustrated that bi-hydroxyl structure in DOPO-based flame retardant benefited the formation of char layer with higher compactness and integrity to serve as a protective shell of interior epoxy matrix. Furthermore, exterior pore size of char residue was narrowed or blocked to avoid the release of heat and volatiles generated from combustion. This study provided a feasible method to improve flame retardancy of lignin-based EP and proposed flame-retardant mechanism both in gaseous and solid phases.
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PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
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2022
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IF 16.744
Yunning Chen,Lu Yang,Yingnan Sun,Renquan Guan,Di Liu,Jie Zhao,Qingkun Shang
A CDs@Cu-HQCA/TiO 2 flower composite photocatalyst (CDs: carbon dots, HQCA : 8-hydroxyquinoline-5-carboxylic acid) was constructed by exploiting the synergy of complex-sensitization, TiO 2 -morphology control, and carbon dot-surface modification. The photocatalytic degradation of phenol, norfloxacin, tetrabromobisphenol A and Cr (VI) by Cu-HQCA/TiO 2 particle, tube, diamond and flower-like show that the Cu-HQCA complex effectively extends the visible light absorption range of composite photocatalysts, and the flower morphology of TiO 2 not only improves the adsorption of pollutants but also enhances the photoelectric response of the composite photocatalyst. In this manner, a CDs@Cu-HQCA/TiO 2 flower catalyst that demonstrates excellent performance for the removal of dexamethasone, which does not degrade well naturally, was prepared, which delivered a rate of degradation of 99.4% and a degree of mineralization of 77.4% for dexamethasone. Possible degradation sites and dexamethasone degradation products were studied by combining computational chemistry with high-resolution mass spectrometry, and a possible mechanism for photogenerated carrier transmission and separation in the CDs@Cu-HQCA/TiO 2 flowers is proposed.
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JOURNAL OF HAZARDOUS MATERIALS
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2022
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IF 14.224
Lu Zhao,Hanlin Zhang,Zhipeng Dai,Ai-Yong Zhang,Jiao Yin,Shuchuan Peng,Heng Liang
The efficient recycling of agricultural chestnut shell waste is of considerable interest due to its large availability and economic feasibility. Herein, an alkaline-activated biochar was thermally prepared using chestnut shell by finely regulating main conditions; its morphological, structural and physic-chemical properties were well characterized. Fenton-like capacity to trigger peroxymonosulfate activation for superior pollutant degradation with high efficiency and good selectivity was validated in different water matrix. Both radical formation and electron transfer were identified as reaction pathways, while the selective non-radical mechanism played the major role in pollutant degradation. Surface ketonic groups were identified as the main reactive sites for non-selective radical production, while crystal edges and structural defects on sp 2 /sp 3 carbon network could smoothly mediate the selective electron transfer from pollutant to oxidant in the non-radical Fenton-like catalysis. The two-mixed radical/non-radical pathways exhibited important advantages for environmental decontamination , in comparison with the one-single radical or non-radical mechanism. Our study provided a promising recycling strategy for agricultural chestnut shell, as well as an environment-friendly catalyst for heterogeneous Fenton-like catalysis in green water purification rendered by the synergistic radical/non-radical reaction pathways.
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ENERGY
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2022
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IF 8.857
Yalan Zhou,Lu Luo,Wen Yan,Zeliang Li,Mizi Fan,Guanben Du,Weigang Zhao
Nitrogen-doped hierarchical carbon cryogels with good monolithic structure are synthesized from phenol (P), melamine (M), and formaldehyde (F) by sol-gel, freeze-drying, and carbonization process with different molar ratios of F/(P + M). The synthesized cryogels have the characteristics of cost-effective and abundant hierarchical pores. The pore structures, chemical properties, and CO 2 adsorption performance of the prepared carbon cryogels are investigated. The results reveal that the PF carbon cryogel without N doping shows poor porosity characteristics, which leads to lower CO 2 adsorption performance. For the N -doped PMF carbon cryogels, with the increase in the molar ratio of F/(P + M), the specific surface area and micropore volume decreases from 1160.6 to 874.1 m 2 /g and from 0.47 to 0.35 cm 3 /g, respectively, indicating that a lower formaldehyde content is conducive to the formation of more micropores and higher specific surface area. The carbon cryogel PMF2.0 (F/(P + M) = 2.0) exhibits a CO 2 adsorption capacity as high as 5.79 mmol/g, and it also has a high CO 2 /N 2 adsorption selectivity (13.43) and isosteric adsorption heat (33.06 kJ/mol). Thus, the PMF carbon cryogel exhibits immense potential as an adsorbent for CO 2 capture, and its excellent performance is attributed to the synergistic effect of N doping and abundant micropores with appropriate size.
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PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
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2022
·Vol. 119
·期 3
·e2114138119
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IF 12.779
Junhui Wang,Qi Fu,Jiaxing Yu,Huangsheng Yang,Zhengping Hao,Fang Zhu,Gangfeng Ouyang
The Fenton-like process catalyzed by metal-free materials presents one of the most promising strategies to deal with the ever-growing environmental pollution. However, to develop improved catalysts with adequate activity, complicated preparation/modification processes and harsh conditions are always needed. Herein, we proposed an ultrafast and facile strategy to convert various inefficient commercial nanocarbons into highly active catalysts by noncovalent functionalization with polyethylenimine (PEI). The modified catalysts could be in situ fabricated by direct addition of PEI aqueous solution into the nanocarbon suspensions within 30 s and without any tedious treatment. The unexpectedly high catalytic activity is even superior to that of the single-atom catalyst and could reach as high as 400 times higher than the pristine carbon material. Theoretical and experimental results reveal that PEI creates net negative charge via intermolecular charge transfer, rendering the catalyst higher persulfate activation efficiency.
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POLYMER DEGRADATION AND STABILITY
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2022
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IF 5.204
Juxiang Chen,Ke Zhang,Kuiyuan Zhang,Bo Jiang,Yudong Huang
Phenolic resins with irreversible cross-links structure make them difficult to degrade and recycle. It is an emerging trend for phenolic resins thermoset to develop a rapid and facile closed-loop recycling approach. Herein, the degradable and reprocessable phenolic thermosets (PRTs) based on reversible acetal bonds were synthesized by tri(ethylene glycol) divinyl ether (TEGDVE) and linear phenolic resin through one-step “click” addition reaction. By employing the chain mobility induced by dynamic weak acetal motifs and linear TEGDVE in PRTs, the mechanical strengths could be rationally adjusted, and more moderate reprocessing and degradation conditions were achieved. Accordingly, the flexible structure units containing weak reversible acetal linkages were expected to accelerate the mobility of the chain segments and decrease the reprocessing temperature, while the linear phenolic structure afforded the high mechanical strength. Remarkedly, a champion degradation rate of 121.8 mg·mL −1 ·h −1 was achieved under acid condition by adjusting the ratio of flexible chains consisting of dynamic acetal bonds. In addition, compared with pristine PRTs, regenerative one maintained 93.41% of elongation at break. This work may shed a light for realizing degradable and reprocessable dynamic network materials with high efficiency.
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Analytical Methods
·
2022
·Vol. 14
·期 9
·892-899
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IF 3.532
Haotian Zhong,Yuting Xue,Bin Liu,Zhengbo Chen,Kai Li,Xia Zuo
Phenols are harmful to the human body and the environment. Since there are a variety of phenols in actual samples, this requires a sensor which possesses the ability to simultaneously distinguish them. Herein, we report a colorimetric sensor array, which uses two nanozymes (Fe–N–C nanozymes and Cu–N–C nanozymes) as electronic tongues for fingerprint identification of six phenols (2,4,6-trichlorophenol (2,4,6-Tri), 4-nitrophenol (P-np), phenol (Phe), 3-chlorophenol (3-CP), 4-chlorophenol (4-CP), and o-nitrophenol (O-np)) in the environment. Nanozymes catalyzed the reaction of hydrogen peroxide, different phenols and 4-aminoantipyrine (4-AAP) to produce different color variations. These signal changes as fingerprints encouraged us to develop a pattern recognition method for the identification of phenols by linear discriminant analysis (LDA). The six phenols at 50 nM have their own response patterns, respectively. Surprisingly, this sensor array had distinguished the six phenols in actual samples successfully.
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Journal of Environmental Chemical Engineering
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2022
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IF 7.968
Yifan Feng,Xu Huang,Huifang Wu,Dawei Li,Yi Sun
Nanomaterials coated ceramic membranes have become one of the most promising methods to degrade organic pollution. In this study, low crystalline metal nanomaterials were coated on ceramic membranes for the first time. This research fabricated a ceramic membrane with low crystalline Fe 2 O 3 @carboxylic multi-walled carbon nanotubes (CMWCNTs) and evaluated its aromatic compounds-degrading ability and self-cleaning ability. The coated membrane demonstrated an excellent removal rate (＞90%) of phenol and atrazine in 120 min’s continuous flow filtration via surface photo-Fenton reaction. Quenching experiments reveal the active substances of the reaction system were singlet oxygen ( 1 O 2 ) and a small amount of hydroxyl radical (·OH). With humic acid (HA) and bovine serum albumin (BSA) as model pollutants, the polluted membranes recovered 84.4% and 77.0% flux through the photo-Fenton reaction respectively, which proved the self-cleaning performance of the coated membrane. After 6 cycles, an average degradation efficiency of 92% for phenol was maintained in continuous flow filtration. These results indicated the efficacy of the photo-Fenton coupling coated membrane for treating organically polluted water and its relevance for the design and application of future photo-Fenton membrane filtration system.
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CHEMICAL ENGINEERING JOURNAL
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2022
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IF 16.744
Sen Dang,Wei Hou,Yulin Min,Junfeng Wu,Qunjie Xu,Penghui Shi
This study aimed to further expand the scope of use of spent lithium-ion batteries (LIBs) and improve their value. We proposed a dual-function electro-oxidation strategy that can realize the highly selective recovery of Li + from spent NCM batteries and the in situ modification of delithiation materials. Under the optimum conditions, the selective recovery rate of Li + exceeded 99%. After electro-oxidation, the electrolyte can be directly heated and concentrated to obtain Li 2 CO 3 . Moreover, the large number of oxygen vacancies and metal vacancies produced by electro-oxidation, as well as the changes in structure and morphology, enabled the delithiation material to exhibit excellent catalytic performance. Within 30 min, the degradation rate of sulfamethoxazole reached 100%. This strategy can be used to recycle and reuse spent LIBs and thus achieve the goal of “turning waste into treasure”.
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危险品化学品经营许可证（带存储）