HIGH PERFORMANCE POLYMERS
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2021
·
IF 2.161
Dandan Li,Chengyang Wang,Shengqi Ma,Hongwei Zhou,Ran Lu
To prepare soluble polyimides with high temperature resistance, two new diamine monomers, namely, 2,2′-(4,4′-oxybisphenylene)-bis(1-phenyl-5-aminobenzimidazole) (5a), and 2,2′-(4,4′-hexafluoroisopropylidene)-bis(1-phenyl-5- aminobenzimidazole) (5b), were synthesized and exploited to prepare three series of poly(benzimidazole imides)s (PBIIs) by a conventional two-stage synthesis. The resulting PI films were flexible and tough, possessing high glass-transition temperatures (Tgs = 311°C–390°C), improved optical transparency, and excellent solubility. Moreover, the effect of different configuration on performance was revealed, and these data provided a feasible method to enhance both Tg and solubility of PIs by incorporating N-phenyl benzimidazole and corresponding functional moieties.
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高影响因子
Nanoscale
·
2021
·Vol. 14
·期 5
·1796-1806
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IF 7.79
Wenyan Yin,Milin Zhang,Jingyuan Liu,Khaled Tawfik Alali,Jing Yu,Jiahui Zhu,Peili Liu,Rumin Li,Jun Wang
Electrochemical sensors using ionic liquids as electrolytes for oxygen detection are now getting more and more attention. Recently, an ionic liquid combined with an electrochemically active catalyst system has become popular for boosting the sensing performance of oxygen sensors. In this work, the imidazolyl-based ionic liquid 1-butyl-2,3-dimethylimidazole bis((trifluoromethyl)sulfonyl)imide [Bmmim][TFSI] is first prepared by a facile two-step method. Subsequently, a transition metal and N-codoped porous carbon oxygen reduction electrochemical catalyst Cu–N/C is synthesized by calcining the Cu-doped ZIF-8 precursor and then blending it in different ratios with the ionic liquid [Bmmim][TFSI] as composite electrolytes for oxygen detection. The composite electrolyte Cu–N/C/[Bmmim][TFSI] exhibits increased responses in cyclic voltammetry (CV) and chronoamperometry (CA) relative to that of the pure ionic liquid. Furthermore, the CV and CA data show that 6% Cu–N/C/[Bmmim][TFSI] has the optimum oxygen sensing response with an enhanced reduction peak current, a sensitivity of 0.1678 μA/[% O2] and a good linear fitting coefficient of 0.9991. In conclusion, the results confirm the success of using Cu–N/C as an electrochemical catalyst composed of the Cu–N/C/[Bmmim][TFSI] electrolyte for improving the responsivity, stability and sensitivity towards a wide range of oxygen concentrations.
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高影响因子
CATALYSIS LETTERS
·
2021
·Vol. 152
·期 9
·2607-2624
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IF 3.186
Zhang Qian,Chen Si,Yu Yong Bo,Hong Jun-ming
Simultaneous pollution degradation and disinfection were seldom discussed in the field of electrocatalytic oxidation. In this work, N-doped graphene (N-GN) was selected as anode to ensure the high performance of paracetamol (APAP) degradation. With N doping, the activity of N-GN is evidently improved because of the better surface area, active defects, and conductivity compared with graphene. The generation of active chlorine and O 2 . − on the N-GN surface played an important role in APAP degradation. Compared with other operation parameters (such as pH and current density), environmental microorganisms exhibited more negative interference for APAP degradation. However, evident disinfection effects can be observed because of the release of fulvic and humic acids from microorganisms. In particular, active chlorine is evidently more effective than O 2 . − for disinfection. The simultaneous APAP degradation and disinfection observed in this research provided the possible technology of electrocatalytic oxidation via N-GN for practical application. Graphical Abstract
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高影响因子
Journal of Materials Chemistry B
·
2021
·Vol. 9
·期 23
·4690-4699
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IF 6.331
Xue Wang,Shengxu Qian,Dongdong Wang,Cunli Wang,Haijuan Qin,Lang Peng,Wenqi Lu,Yahui Zhang,Guangyan Qing
Sialic acids located at the terminal end of glycans are densely attached to cell surfaces and play crucial and distinctive roles in a variety of physiological and pathological processes, such as neural development, cell–cell interactions, autoimmunity and cancers. However, due to the subtle structural differences of sialic acid species and the complicated composition of glycans, the precise recognition of sialylated glycans is difficult. Here, a fluorescent dynamic response system based on a pyrene-conjugated histidine (PyHis) supramolecular gel is proposed. Driven by π–π stacking and intermolecular hydrogen bonds, PyHis exhibits a strong self-assembly ability and forms stable gels. It is found that introduction of N-acetylneuraminic acid (a typical sialic acid) can prevent this self-assembly process, whereas other monosaccharides or sialic acid analogs have no significant effect on it. Interestingly, a sialylated glycan also has a remarkable inhibitory effect on the gel formation, which highlights the high selectivity of the gel dynamic response system. Analysis of the mechanism reveals that the sialic acid or sialylated glycan can interact closely with two PyHis molecules stacked together in the assemblies via hydrogen bonding interactions, thereby preventing the ordered accumulation of the gelators. It is worth noting that the high-efficiency sialic acid recognition effect is not observed at the single molecule level but at the supramolecular level, indicating the unique superiority of the supramolecular self-assembly system in biomolecular recognition and response. This work shows the promising prospects of using supramolecular gels in assembly engineering, regenerative medicine, tumour cell sorting and cancer diagnosis.
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高影响因子
APPLIED SURFACE SCIENCE
·
2021
·
IF 6.707
Jianfei Xiao,Yuan Wang,Tian C. Zhang,Shaojun Yuan
Nitrogen-sulfur codoped porous carbon (NSPC) is a promising advanced material, showing great application potential in greenhouse gas capture and energy storage. Here, a novel NSPC with controllable porous structure was fabricated via pyrolysis and activation of N, -containing polycondensates, which were synthesized by one-pot polycondensation reaction of triglycidyl isocyanurate, glucose and thiourea. The obtained sample NSPC-1-650 showed cross-linked spherical morphology with uniform pore size (2.61 nm), large specific surface areas (1927.46 m 2 ·g −1 ), and the doping of nitrogen (4 wt%) and sulfur (2 wt%), which leaded to a good CO 2 adsorption capability (5.56 mmol·g −1 at 298.15 K, 5 bar) and excellent stability. Additionally, when used as a supercapacitor, the NSPC-1-650 sample showed an ultrahigh specific capacitance (224.3F·g −1 at 1 A·g −1 in 6 M KOH electrolyte), an excellent rate capability, and good stability (retained > 85% capacity after 5000 cycles). Notably, the all solid-state symmetrical NSPC-1-650-based supercapacitors delivered a high energy density (the maximal value = 7.8 Wh·Kg −1 ) and power density (the maximal value = 4500 W·Kg −1 ). These results suggest that NSPC-1-650 be a competitive candidate as a CO 2 adsorbent and supercapacitor.
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高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
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2021
·
IF 4.539
Liting Xu,Yuhong Lv,Xingwei Li
The commercial development of direct methanol fuel cells (DMFCs) has been hampered by Pt anode catalysts with a high cost, and its long-term stability is also unsatisfactory, especially in acidic media. Therefore, the development of catalysts with high efficiency and low cost is an urgent problem. To reduce costs, a simple solution is to use non-precious transition metals to partially replace precious metal Pt. Moreover, the catalyst supports are also crucial in term of stabilizing and dispersing Pt-based catalysts. Herein, N-doped carbon-stabilized Pt 3 Co catalyst (Pt 3 Co/NC) is successfully prepared via the pyrolysis of Pt-encapsulated Co/Zn-based zeolitic imidazolate frameworks (Pt@ZIF-8/67). And catalytic performance of Pt 3 Co/NC catalyst is studied in 0.5 M H 2 SO 4 solution containing 0.5 M CH 3 OH. The area specific activity of Pt 3 Co/NC catalyst is 1.15 mA cm −2 Pt, which is about 4 times as great as that of commercial Pt/C. Furthermore, the as-prepared catalyst also shows better stability compared to Pt/C.
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高影响因子
IONICS
·
2021
·Vol. 27
·期 9
·3975-3985
·
IF 2.817
Wang Zhiyi,Wang Yutian,Tang Jingtao,Wang Kaizhao,Chen Tianyou,Wang Kaijun,Hu Jin
Among the currently studied nitrogen-doped Pt-C catalysts, the environmental friendliness of the nitrogen source and the stability of Pt-C catalysts for fuel cells are urgent issues to be solved. In this study, nitrogen-doped platinum-based catalyst (CSC/BP-Pt) with excellent stability for the ORR is prepared by a self-doping method based on chitosan (CS), a green biomass material with both nitrogen and carbon sources, in combination with conductive carbon black (BP2000). Finally, the N content of the catalyst is as high as 5.8 wt%, which is higher than most comparable catalysts (3–5 wt%). And electrochemical tests show that the CSC/BP-Pt electrochemical active surface area (ECSA) = 154.1 m 2 /g Pt , half-wave potential (E 1/2 = 0.85 V RHE ) has a better electrochemical performance than the commercial Pt/C (20 wt%), while the half-wave potential is reduced at 10,000 cycles of cyclic voltammetry with almost no attenuation (only 7 mVcompared to 31 mV of Pt/C). Besides, possible mechanisms to improve the activity and stability of CSC/BP-Pt are preliminarily proposed.
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高影响因子
Journal of the Taiwan Institute of Chemical Engineers
·
2021
·
IF 5.876
Xiuhui Zhai,Xiang Wang,Xinle Pang,Jun Zhang,Qiong Wu,Weidan Na,Yingmei Zhou,Lin Tian
Exploiting effective and low-cost electrocatalysts toward water oxidation is of vital significance for boosting overall water splitting. Herein, we proposed a simple method for constructing dendritic N-doped carbon/ manganese oxides (N-C/MnO x ) hybrid nanocomposites by annealing the composite of nitrogen-doped carbon quantum dots (N-CQDs) and γ-MnOOH (γ-MnOOH@N-CQDs) at different temperatures under N 2 /O 2 atmosphere. The obtained N-C/MnO x exhibited remarkable electrocatalytic activity and stability for oxygen evolution reaction (OER) owing to their unique dendritic structure, rich oxygen vacancies, optimized electronic structure, abundant Mn-C/N, and large electrochemical active area. Among of the prepared N-C/MnO x hybrid nanocomposites, N-C/Mn 2 O 3 showed the best performance toward OER with an overpotential of merely 347 mV to reach to 10 mA cm −2 , along with a small Tafel slope of 75.51 mV dec −1 . More remarkably, by combining Pt/C with N-C/Mn 2 O 3 for overall water splitting, a battery voltage of only 1.67 V is needed to reach the 10 mA cm −2 , rivaling the activity of the state-of-the-art IrO 2 ‖ Pt/C couple.
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高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2021
·
IF 8.128
Yingjie Guo,Zhongke Wang,Yuyang Wang,Lixia Ma,Nan Zhang,Ruibin Jiang
The development of nonprecious metal-based electrocatalysts for oxygen reduction reaction (ORR) is a central task in renewable electrochemical energy conversion and storage technologies. Iron-nitrogen doped carbon-based (Fe−N/C) materials are promising alternatives to Pt-based ORR electrocatalysts. Owing to large specific surface area and outstanding electrical conductivity, carbon black is an inborn support for electrocatalysts. Unfortunately, the direct incorporation of Fe−N x moieties onto the surface of carbon black has not been realized to date. Herein, Fe−N x moieties are directly incorporated onto the surface of carbon black through surface modification and the following Fe and N co-doping. The obtained Fe and N co-doped carbon back (Fe−N/CB) catalyst has very large specific surface area and abundant accessible Fe−N x moieties. As a result, Fe−N/CB electrocatalyst exhibits a more positive half-wave potential (0.86 V) than Pt/C. The Fe−N/CB catalyst also displays better stability and methanol resistance than Pt/C. The Zn-air battery with Fe−N/CB as cathodic catalyst shows a maximum power density of 68 mW cm −2 and a specific capacity of 676 mAh g Zn -1 . Our finding provides a convenient and low-cost approach to fabricating efficient M−N/C-based catalysts and will be helpful to the development of renewable electrochemical energy conversion and storage technologies.
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高影响因子
CHEMISTRY OF MATERIALS
·
2021
·
IF 9.811
Rong Wang,Qingfu Cai,Yunyang Zhu,Zhen Mi,Weijun Weng,Yicheng Liu,Jiaxun Wan,Jianhua Hu,Changchun Wang,Dong Yang,Jia Guo
Low-bandgap covalent organic frameworks (COFs) emerge as one of the most intriguing conjugated polymers for the development of electronic devices, while they often lack desirable electron affinity, thereby compromising the activity and stability in electrochemical transformation. Here, we report an n-type semiconducting two-dimensional (2D) COF, featuring a low bandgap (1.36 eV) and strong electron affinity (4.41 eV) as well as high crystallinity and porosity. The columnar stacking array of the benzobisthiadiazole moiety in 2D COFs plays a critical role in elevating electroactivity. It not only leads to the outstanding electrical conductivity and air stability upon reductive doping but also enables the boost of transformation kinetics for polysulfides on the separators of lithium–sulfur batteries causing a higher capacity and better cycling performance. The design strategy underpins the versatile development of electroactive COF materials with desirable electronic properties and promotes their applicability in energy storage and electronics.
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高影响因子
Catalysts
·
2021
·Vol. 11
·期 5
·561
·
IF 4.146
Fangyuan Wang,Yu Liu,Zhiling Song,Zhichao Miao,Jinping Zhao
Electrochemical CO2reduction reaction (CO2RR) is eliciting considerable attention in relation to the carbon cycle and carbon neutrality. As for the practical application of CO2RR, the electrocatalyst is a crucial factor, but, even so, designing and synthesizing an excellent catalyst remains a significant challenge. In this paper, the coordination compound of Ni ions and dimethylglyoxime (DMG) was employed as a precursor to modify reduced graphene oxide (rGO) for CO2RR. The textural properties and chemical bonds of as-obtained rGO, N–C–rGO, Ni–rGO, Ni–N–C, and Ni–N–C–rGO materials were investigated in detail, and the role of Ni, N–C, and rGO in the CO2RR were researched and confirmed. Among all the catalysts, the Ni–N–C–rGO showed the optimal catalytic activity and selectivity with a high current density of 10 mA cm−2and FE(CO)% of 85% at −0.87 V vs. RHE. In addition, there was no obvious decrease in activity for 10 h. Therefore, the Ni–N–C–rGO is a promising catalyst for CO2RR to CO.Keywords:metallic Ni;N-doped carbon;reduced graphene oxide;electrocatalyst;electrochemical CO2reduction
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高影响因子
JOURNAL OF CHROMATOGRAPHY A
·
2021
·
IF 4.759
Huikai Shao,Liang Lai,Dongsheng Xu,Jacques Crommen,Qiqin Wang,Zhengjin Jiang
In this study, to selectively enrich N -glycans from complex biological samples, a novel Zr(IV) modified adenosine triphosphate (Zr(IV)-ATP) functionalized monolith was prepared through a facile approach. Well-defined macroporous structure was observed in the ATP functionalized monolith, which allows rapid mass transfer under low backpressure and is beneficial for the enrichment of N-glycans. After being modified with Zr(IV), the resulting Zr(IV)-ATP functionalized monolith could selectively capture N -glycans through the specific interactions between the sulfonate groups of 1-aminopyrene-3,6,8-trisulfonic acid (APTS) labeled N -glycans and Zr(IV). An APTS labeled maltooligosaccharide ladder was used to optimize the enrichment conditions for APTS labeled N -glycans, and capillary electrophoresis (CE) coupled with laser-induced fluorescence (LIF) detector was employed to evaluate the enrichment efficiency. The results show that the APTS labeled maltooligosaccharides could be enriched under the selected conditions and the signal amplify factors of the maltooligosaccharides were between 7.4 and 19.5 with RSDs for reproducibility from 4.0% to 8.3% (n = 3). Finally, the proposed method was successfully used for the enrichment and detection of N -glycans released from Ribonuclease B.
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高影响因子
危险品化学品经营许可证（带存储）