ChemistrySelect
·
2022
·Vol. 7
·期 31
·e202200638
·
IF 2.307
Cheng Tang,Tao Hu,Yanglei Li,Xiaoli Hu,Kunpeng Song
Graphical We report a weaving strategy to adjust the backbone structure of alkaline lignin, by which porous materials with large specific surface area and uniform pore size distribution can be obtained, exhibiting good adsorption capacity for RhB. Lignin is widely found in nature and attracts increasing concern as the renewable carbon material. In this work, hyper-crosslinked lignin was successfully prepared and applied for adsorbing dyes such as rhodamine B (RhB), methylene blue (MB) and Congo Red (CR) in wastewater. The characteristics of the alkaline lignin and hyper-crosslinked lignin were identified by Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and N 2 adsorption and desorption measurements. The results show that the hyper-crosslinked lignin is composed of uniform and porous nanoparticles with smaller size as compared to the sheet and- block structure of alkaline lignin. The specific surface area and pore structure of the hyper-crosslinked lignin have been greatly optimized, while retaining the functional groups on the surface of the alkali lignin. The Brunner-Emmet-Teller (BET) surface area of the hyper-crosslinked lignin reaches up to 402.8 m 2 ⋅ g −1 , and the adsorption capacity of RhB is up to 1332 mg ⋅ g −1 . The isotherm model and thermodynamic results indicate that the adsorption process conforms to the Langmuir model, mainly showing a single-layer spontaneous chemical endothermic process. In addition, HCP−L showed good selective adsorption performance for cationic dyes with the adsorption amounts of 228 mg ⋅ g −1 for MB, while that of the anionic dye CR (89 mg ⋅ g −1 ) was comparatively low. The adsorption mechanism was hydrogen bonding and π-π stacking in addition to the electrostatic effect caused by the negative charge on the surface of HCP−L.
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JOURNAL OF MEMBRANE SCIENCE
·
2022
·
IF 10.53
Wei Yuan,Lingping Zeng,Shangkun Jiang,Caili Yuan,Qian He,Jianchuan Wang,Qiang Liao,Zidong Wei
Anion exchange membrane fuel cells (AEMFCs) is a potential substitute to the prevailing proton exchange membrane fuel cells (PEMFCs), since non-precious metal catalysts can be applied in the AEMFCs, leading to much lower cost of it. However, anion exchange membranes (AEMs), as a crucial component of the AEMFCs, has always been a challenge in the commercialization of AEMFCs, such as poor life-time and conductivity . Herein, a series of poly(carbazolyl aryl piperidinium) AEMs and ionomers are prepared with non-rotatable rigid carbazole group next to piperidinium ring on the polymer backbone for the first time, and the membranes were fabricated by mass production method of tape-casting. The membranes exhibit extraordinary comprehensive performance, for instance, high hydroxide conductivity up to 204.8 mS cm −1 at 90 °C, good mechanical strength of >50 MPa in wet state, low hydrogen permeability and excellent alkaline stability of only 3% decline after 2100 h in 1 M KOH at 80 °C. Fuel cell (H 2 –O 2 ) based on the as-prepared membranes and ionomers shows outstanding peak power density of 1.72 W cm −2 at a quite low back pressure of 20 kPa, and only 2.6% decay was observed after 120 h.
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Catalysis Science & Technology
·
2022
·Vol. 12
·期 12
·3982-3991
·
IF 6.177
Guang-Rong Ding,Yao-Feng Wang,Guo-Yi Duan,Tao Guo,Xiao-Feng Xu,Chun-Shan Li,Bao-Hua Xu
Adiponitrile (ADN) is a key intermediate for the industrial production of polyamides represented by nylon 66. In this study, the chemoselective nitrilation of dimethyl adipate (DMA) with ammonia (NH3) under continuous flow conditions was studied on carbon encapsulated oxygen-deficient WOx<3 catalysts (WOx@C/C). A combination of dispersed anchor sites at a poly(ionic liquid) (PIL) template, the porosity of active carbon support, and the calcination procedure allows the formation of effective WOx@C-600-0.25-A1, persisting high BET specific surface area and WO2.83 active phase of appropriate size. It delivers ADN and methyl 5-cyanopentanoate (MCP) with an excellent selectivity of up to 95.8% at a weight hourly space velocity of DMA (WHSVDMA) of ∼0.64 gDMA gcat−1 h−1 and an NH3/DMA molar ratio of 13 : 1. A tandem reaction route from DMA to ADN via MCP was elucidated, wherein the second nitrilation of MCP to ADN proceeds very slowly. Besides, both CDMA and TONADN/TONMCP are significantly influenced by the physical dispersion and size of the active WO2.83 phase in WOx@C/C.
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ACS Sustainable Chemistry & Engineering
·
2022
·
IF 9.224
Lingling Ma,Lv Li,Minghao Yuan,Lei Bai,Anran Zhang,Xiaoming Yan,Gaohong He,Fengxiang Zhang
The hydroxide conductivity and alkaline stability play a significant role in the application of an anion exchange membranes (AEMs) fuel cell. These high performances are closely related to the structure of the polymer. Side-chain structure is commonly used to construct microphase separation. On this basis, a new strategy is to incorporate a rigid bulky structure into an AEM to break chain packing and reduce resistance against hydroxide ion transport. In this work, rigid bulky hydrophilic–hydrophobic side-chain grafted, ether-free poly(biphenyl indole) (PBN) AEMs are designed and prepared by chemical incorporation of hydrophilic bulky cyclodextrin and hydrophobic bulky adamantane onto the PBN backbone. The enhanced driving force of microphase separation and the enlarged free volume can make for high hydroxide conductivity. The fabricated AEM with an ion exchange capacity (IEC) of 1.81 mmol g–1 shows a conductivity of 122.0 mS cm–1 at 80 °C, which can be retained by 90% after treatment of the AEM in a 1 M NaOH solution at 80 °C for 1008 h. Its single H2/O2 fuel cell yields a peak power density of 603 mW cm–2 at 60 °C; the fuel cell can maintain 70.2% of its initial voltage after operating for 30 h. This strategy provides a new and effective route for the preparation of AEMs with superior performance.
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ACS Applied Nano Materials
·
2022
·
IF 6.14
Lijing Zhang,Jiaqi Han,Yuchao Wang,Wenbo Yang,Shengyang Tao
Achieving a room-temperature Suzuki–Miyaura coupling (SMC) with high efficiency is of great significance to the development of low-carbon organic synthesis. Nevertheless, it is still a great challenge to construct a promising nanocatalyst with high activity for room-temperature SMC reaction. In this paper, a strong alkaline-supported nanocatalyst Pd/Mg(OH)2/MgO–ZrO2 was rationally developed based on MgO–ZrO2 hybrid nanofibers. Physicochemical characterizations present that the in situ conversion of MgO to Mg(OH)2 on the surface of the nanofibers results in a great increase in surface alkalinity of the carrier. The strong alkalinity can greatly accelerate the oxidation addition and transmetalation of the SMC process, resulting in the obvious reduction of activation energy of the reaction (Ea = 9.0 kJmol–1 for Ph–Br). The coupling conversion can reach up to 100% at room temperature within 8 min with a maximum TOF > 6516 h–1. It also shows an excellent performance in substrate applicability and chlorobenzene activation. The rational design of a high-basicity catalyst for room-temperature SMC will be a rewarding attempt for the development of low-carbon green organic synthesis.
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Micro & Nano Letters
·
2022
·Vol. 17
·期 6
·125-133
·
IF 0.98
Jian-Jun Shi,Zhe Wang,Yan Wang,Rui-Wen Shu,Ping Yang
A photoelectrochemical sensor has been developed for the detection of the polycyclic aromatic hydrocarbon pollutant benzo [a]pyrene (BaP). An n -butyl lithium intercalation stripping method is applied to prepare tungsten disulphide nanosheets (WS 2 NSs). WS 2 NSs and β-cyclodextrin (β-CD)-modified MoS 2 quantum dots (QDs) are then compounded by hydrogen bonding between the amino and hydroxyl groups. After assembly on an indium tin oxide electrode, the energy level matching and synergistic photoelectric effect between β-CD-MoS 2 QDs and WS 2 NSs reduced the combination of photogenerated electrons and holes and an enhanced photocurrent signal is observed. As a result of the host–guest interaction between β-CD and BaP, BaP could bind to the β-CD-MoS 2 QDs in the nanocomposites, which hinders the electron migration to the electrode and weakened the photocurrent signal. Thus, the trace detection of BaP is realized. The rate of photocurrent change is also related to the BaP concentration from 1 to 20 nmol/L with a detection limit of 0.33 nmol/L. In summary, a highly sensitive and selective photoelectrochemical sensor for the detection of BaP is successfully constructed.
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ChemSusChem
·
2021
·Vol. 15
·期 4
·e202102455
·
IF 8.928
Xingwang Lan,Juan Wang,Qing Li,Aiqing Wang,Yize Zhang,Xianheng Yang,Guoyi Bai
Graphical Building bridges : Acetylene or vinylene-bridged π-conjugated covalent triazine polymers, A-CTP-DPA and V-CTP-DPE, are fabricated toward metal-free photocatalytic oxidation under visible light irradiation. Impressively, compared to the one without acetylene or vinylene bridge, A-CTP-DPA and V-CTP-DPE exhibit superior activity in photocatalytic selective oxidation of sulfides and oxidative coupling of amines. Solar-driven photocatalytic chemical transformation provides a sustainable strategy to produce valuable feedstock, but designing photocatalysts with high efficiency remains challenging. Herein, two acetylene- or vinylene-bridged π-conjugated covalent triazine polymers, A-CTP-DPA and V-CTP-DPE, were successfully fabricated toward metal-free photocatalytic oxidation under visible light irradiation. Compared to the one without acetylene or vinylene bridge, both resulting polymers exhibited superior activity in photocatalytic selective oxidation of sulfides and oxidative coupling of amines; in particular, A-CTP-DPA delivered an optimal photocatalytic performance. The superior activity was attributed to the broadened spectral response range, effective separation, rapid transportation of photogenerated charge carriers, and abundant active sites for photogenerated electrons due to the existence of the acetylene bridge in the framework. This work highlights the potential of acetylene and vinylene bridges in tuning catalytic efficiency of organic semiconductors, providing a guideline for the design of efficient photocatalysts.
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PubMed
高影响因子
Energy Storage Materials
·
2023
·
IF 20.4
Chen Wu,Jieming Hu,Hanxian Chen,Chengyi Zhang,Mingli Xu,Lin Zhuang,Xinping Ai,Jiangfeng Qian
Prussian blue analogues (PBAs) have been attracting intense attention owing to its two-electron storage capability and considerable cost advantage, especially in Na-ion and K-ion batteries. However, things are quite different when it comes to Li-ion batteries, because lithium-containing Li 4 Fe(CN) 6 precursor is not commercially available and thus the traditionally prepared Li-deficient FeFe(CN) 6 products fail to couple with commercial graphite anode for full cells. Herein, we put forward a potential matching principle to guide the chemical pre-lithiation of FeFe(CN) 6 into a Li-rich Li x FeFe(CN) 6 ( x varies from 0 to 2) cathode. The potential matching principle was convincingly confirmed by theoretical analysis and over-lithiation experiments. Perylene-Li reagent was elaborately screened to serve as both Li + and electron donor for controllable chemical lithiation reaction while preserving the host framework stable. Our work provided a general guiding principle and effective methodology for controllable synthesis of Prussian blue analogues in gradient lithiation depth, which could be served as a platform for in-depth, systematic and comprehensive research on the properties of PBAs materials.
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ADVANCED FUNCTIONAL MATERIALS
·
2023
·Vol. 33
·期 35
·2302364
·
IF 19
Guodong Xu,Ji Pan,Xiuyang Zou,Zhiyu Jin,Jiale Zhang,Pengda Fang,Qiuhuan Zhang,Zhe Sun,Feng Yan
The performance of alkaline fuel cells is severely limited by substandard anion exchange membranes (AEMs) due to the lower ionic conductivity compared to the proton exchange membranes. The ionic conductivity of AEMs can be effectively improved by regulating the microphase structure, but it still cannot meet the practical use requirements. Here, enhanced microphase-separated structures are constructed by the cooperativity of highly hydrophilic dual cations and highly hydrophobic fluorinated side chains. Meanwhile, the introduction of O enhances the flexibility of side chains and facilitates the formation of ion transport channels. The dual piperidinium cation functionalized membrane (PB2Pip-5C8F) which is grafted with the ultra-hydrophobic fluorocarbon chain exhibits a high conductivity of 74.4 mS cm −1 at 30 °C and 168.46 mS cm −1 at 80 °C. Furthermore, the PB2Pip-5C8F membrane achieves the highest peak power density of 718 mW cm −2 at 80 °C under a current density of 1197 mA cm −2 without back pressure. A long-term life cell test of this AEM shows a low voltage decay rate of 1.68 mV h −1 over 70 h of operation at 80 °C.
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ACS Catalysis
·
2023
·
IF 12.9
Dong Ji,Peng Guo,Yongjie Xi,Jinlei Li,Jia Wang,Tingting Wang,Fuwei Li
Selective tandem hydrogenation is a promising strategy for catalytic conversion of bulk raw materials with multifunctional groups into high-value-added chemicals via multiple-step reactions. Yet now, one of the current challenges is to develop a multifunctional and stable catalyst enabling the tandem catalysis rather than interrupting at any step reaction, particularly for supported nonprecious metal catalysts. In this work, we report tandem hydrogenation of bulk phthalic anhydride toward the one-pot synthesis of hexahydrophthalide, an emerging monomer of a recyclable polyester, over phosphorus-promoted Ni–Co bimetallic alloy nanoparticle catalysts. The surface composition of catalysts can be easily regulated by changing the Ni/Co molar ratio and the phosphorous functionalization strategy, which could then tune the product selectivity and enhance the stability of this tandem process. The optimal Ni3Co1@NC-P affords 88% selectivity for the desired product and demonstrates promising stability toward the tandem hydrogenation reaction. Systematic experimental and computational studies reveal that the adsorption strength of the intermediates and the ability of hydrogen activation can be altered by the formation of surface metallic Ni species, thus tuning the product selectivity. In addition, the oxidation resistance of Ni3Co1@NC-P was enhanced by the phosphorization treatment, which makes the bimetallic alloy successfully realize the tandem hydrogenation reaction. The finding of this work not only provides a convenient strategy to design and develop efficient and stable non-noble metal-based catalysts for selective tandem hydrogenation reactions, especially involving the hydrodeoxygenation reaction, but also fulfills the straightforward pathway for the preparation of degradable polyester monomer hexahydrophthalide.
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JOURNAL OF MEMBRANE SCIENCE
·
2021
·
IF 8.742
Wei Wei Gou,Wei Ting Gao,Xue Lang Gao,Qiu Gen Zhang,Ai Mei Zhu,Qing Lin Liu
To prepare anion exchange membranes (AEMs) that possess an excellent alkaline resistance, a competitive conductivity and a low swelling ratio (SR), a reasonable molecular structure design is particularly important. Herein, we synthesized ether-free fluoropolymers via a superacid catalyzed polyhydroxyalkylation reaction in one pot, and grafted long flexible multipiperidine cation side chains to different positions of the backbone through Menshutkin reaction. We investigated the effect of hydrophilic-hydrophobic polarity difference on the microphase separation . When the ionic liquid is grafted closer to the fluorine-contained group, AEMs exhibit a more obvious microphase separated structure and larger ion clusters as confirmed by morphology observation. Molecular dynamics simulations also confirmed that the construction of ion channels in PBPip-QAPBF-30% is more efficient than in QAPBPip-PBF-30%. The resulting PBPip-QAPBF-30% AEM exhibits the highest OH − conductivity of 156.4 mS cm −1 with a low SR of 12.9% at 80 °C. The QAPBPip-PBF-30% and PBPip-QAPBF-30% AEMs both show an excellent alkaline stability with the OH − conductivity retention of 93.2% and 95.0% correspondingly after being treated in a 2 M NaOH solution at 80 °C for 1080 h. Moreover, the peak power density of a single cell equipped with PBPip-QAPBF-30% reaches 324.5 mW cm −2 at a current density of 550 mA cm −2 .
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MICROPOROUS AND MESOPOROUS MATERIALS
·
2021
·
IF 5.455
Jianwei Bai,Shuhui Li,Xiaofei Ma,Huijun Yan,Shouzheng Su,Shuang Wang,Jun Wang
Herein, a series of novel amidoxime-functionalized porous polymeric adsorbents using dimethoxymethane (FDA) as the external cross-linker and biphenyl and amidoxime-functionalized 1-(benzyloxy)-4-ethylbenzene (BP-AO) as the original monomers were synthesized in one-pot Friedel-Crafts alkylation reactions via a simple “knitting” synthetic strategy. The adsorbents were characterized by FT-IR, solid-state 13 C NMR/MAS spectrum, N 2 adsorption-desorption, etc. The adsorption mechanism was probed by XPS , which suggests that the η 2 complexation between uranium and amidoxime, and the polymers provide an approach to synthesize novel porous materials. The batch adsorption experiments showed that amidoxime hyper-crosslinked polymer-2 (HCPA-2) displays a uranium adsorption capacity of 27.7 mg/g at pH 6. The static adsorption action was more consistent with the Langmuir model and pseudo-second-order kinetics. Ionic competition experiments showed that K d (U(IV)) is as high as 695.94 mL/g and reusable with a removal rate up to 60% after 7 cycles when 0.1 M HNO 3 was used as a stripping agent, which verifies the practical application potential of the materials.
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