INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
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2020
·
IF 3.573
Yaju Chen,Rongchang Luo,Qinggang Ren,Xiantai Zhou,Hongbing Ji
The development of advanced charged polymers with multifunctionality for heterogeneous catalysis is glamorous but still challenging. Herein, on the basis of function-oriented design philosophy, a series of metalloporphyrin-based porous ionic polymers (PiPs) were first synthesized through a facile and green method via Debus–Radziszewski reaction following click-chemistry principles. Benefiting from the enhancement of rigidity and contortion of the framework, these charged polymers presented improved specific surface area with hierarchical porous structures. The in situ polymerization method also endows them with extremely high density of biactive sites, anion tunability, and good CO2/N2 adsorptive selectivity. As a result, they exhibited excellent catalytic performance, robust recyclability, and good substrate expansibility in the solvent-free synthesis of cyclic carbonates from epoxides and CO2 even at ambient conditions. Exhilaratingly, CoTPP-PiP(Br) could smoothly catalyze this reaction by using simulated flue gas (15% CO2 in 85% N2, v/v) as a raw material under mild conditions. Thus, these functional PiPs diversified the types of porous polymers and provided a promising opportunity for the industrial synthesis of valuable cyclic carbonates from real-world CO2.
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Science Advances
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2020
·Vol. 6
·期 29
·
IF 13.117
Yufeng Liu,Yuan Cheng,He Zhang,Min Zhou,Yijun Yu,Shichao Lin,Bo Jiang,Xiaozhi Zhao,Leiying Miao,Chuan-Wan Wei,Quanyi Liu,Ying-Wu Lin,Yan Du,Christopher J. Butch,Hui Wei
Here, an integrated cascade nanozyme with a formulation of Pt@PCN222-Mn is developed to eliminate excessive reactive oxygen species (ROS). This nanozyme mimics superoxide dismutase by incorporation of a Mn–[5,10,15,20-tetrakis(4-carboxyphenyl)porphyrinato]–based metal-organic framework compound capable of transforming oxygen radicals to hydrogen peroxide. The second mimicked functionality is that of catalase by incorporation of Pt nanoparticles, which catalyze hydrogen peroxide disproportionation to water and oxygen. Both in vitro and in vivo experimental measurements reveal the synergistic ROS-scavenging capacity of such an integrated cascade nanozyme. Two forms of inflammatory bowel disease (IBD; i.e., ulcerative colitis and Crohn’s disease) can be effectively relieved by treatment with the cascade nanozyme. This study not only provides a new method for constructing enzyme-like cascade systems but also illustrates their efficient therapeutic promise in the treatment of in vivo IBDs.
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VACUUM
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2020
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IF 2.906
Han Wu,Siqi Shen,Jun Li,Xiaohong Chen,Zhejuan Zhang,Wei Ou-Yang
Boosted field emission (FE) cathodes of silicon carbide nanowires (SiC NWs) filled with polyaniline (PANI) and polypyrrole (PPY) coatings were prepared via cyclic voltammetry method, which is facile, feasible and capable to control the coating-thickness. As compared to pristine SiC, the average turn-on field ( E on ) of SiC/PANI and SiC/PPY under several of repeat experiment decreased from 1.84 to 1.44 and 1.04 V/μm, respectively. The lowest E on of SiC/PPY even dropped down to 0.95 V/μm with raised field enhancement-factor and conductivity, identifying that the FE properties have been improved by depositing PANI and PPY due to enhanced conductivity. However, the conductivity would be saturated with the continuously increasing depositing-thickness and overly thick coatings would block the efficient FE points and reduce the effective electric field between cathode and anode, causing a worse FE performance instead. Besides, the optimal FE performance was obtained in SiC/PPY, which not only had a much lower E on , but also reinforced the stability. The synergy of conductivity effect and thickness effect found in this study indicates SiC/PPY to be a promising candidate for FE applications in vacuum electronic devices.
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Nanomaterials
·
2020
·Vol. 10
·期 7
·1370
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IF 4.324
Zhenfeng Lin,Ziwei Pan,Yuhao Zhao,Lin Qian,Jingtao Shen,Kai Xia,Yongfu Guo,Zan Qu
PPy-Fe3O4/Kaolin was prepared with polypyrrole functionalized magnetic Kaolin by a simple, green, and low cost method to improve the agglomeration and low adsorption capacity of Kaolin. PPy-Fe3O4/Kaolin was employed to remove Hg2+and the results were characterized by various methods. Relevant factors, including solution pH, dosage of adsorbent, concentration (C0), and temperature (T), were optimized by Response Surface Methodology (RSM) and Central Composite Designs (CCD). The optimal results show that the importance for adsorption factors is pH >T>C0> dosage, and the optimal adsorption conditions of PPy-Fe3O4/Kaolin are pH = 7.2,T= 315 K,C0= 50 mg/L, dosage of 0.05 g/L, and the capacity is 317.1 mg/g. The adsorption process conforms to the pseudo-second-order and Langmuir models. Dubinin–Radushkevich model shows that adsorption process is spontaneous and endothermic. Moreover, the adsorption of mercury by PPy-Fe3O4/Kaolin was achieved mainly through electrostatic attraction, pore diffusion, and chelation between amino functional groups and Hg2+. PPy-Fe3O4/Kaolin has excellent reproducibility, dispersity, and chemical stability, and it is easy to be separated from solution through an external magnetic field. The experiments show that PPy-Fe3O4/Kaolin is an efficient and economical adsorbent towards mercury.Keywords:magnetic material;polypyrrole;kaolin;response surface methodology;mercury
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ACS Applied Materials & Interfaces
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2020
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IF 8.758
Xincheng Ding,Weibing Zhong,Haiqing Jiang,Mufang Li,Yuanli Chen,Ying Lu,Jun Ma,Ashish Yadav,Liyan Yang,Dong Wang
Wearable piezoresistive sensors have attracted wide attention for application in human activities monitoring, smart robots, medical detection, etc. However, most of the sensing signals collected from the piezoresistive sensor are triggered by coupling forces, such as the combination of tension and pressure. Thus, the piezoresistive sensor would be incapable of accurately monitoring and evaluating specific human motion due to the mutual interference from tension and pressure, as the tension is difficult to be decoupled or eliminated from the coupling forces. Herein a prestretchable conductive yarn (PCY) sensor with pressure sensitivity but tension insensitivity was introduced to remove the disturbance from tension. The PCY-based piezoresistive sensor is tension insensitive (gauge factor of 0.11) but pressure sensitive (sensitivity of 187.33 MPa–1). The fabric-based pressure sensor assembled with cross-arranged PCY weft and warp revealed magnified pressure sensitivity compared with the single PCY yarn sensor, as well as tension insensitivity to strain and tensile angle. Moreover, it possessed benign cyclicity during 5000 cycles of pressing/releasing. Therefore, the fabric piezoresistive sensor based on weaved conductive yarns is suitable for highly accurate and large area pressure detection, such as monitoring massage intensity of acupuncture points.
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ENVIRONMENTAL RESEARCH
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2020
·
IF 5.715
Zexiang Wang,Lihui Huang,Yuxia Wang,Xiaoming Chen,Hongfei Ren
Metal-free catalysts are widely considered as promising alternatives to traditional metal-based catalysts, which can effectively activate peroxymonosulfate (PMS). In this study, a novel metal-free catalyst, carbonized polypyrrole (CPPy) was synthesized through high-temperature carbonization of PPy, easily achieving the in situ N doping without the addition of nitrogen sources. Tetracycline (TC) was selected as the target contaminant to assess the catalytic activity of the CPPy/PMS system. Enhanced catalytic activity was observed in CPPy/PMS over a wide pH range (3.0–9.0), and the removal rate of TC by CPPy-3/PMS reached 91.3% after 10 min. After regenerating the used catalyst, the catalytic activity was refreshed, implying its stability and recyclability . The catalytic degradation of TC by CPPy/PMS was mainly attributed to a non-radical process. CPPy, as an intermediary, grabbed electrons from the electron-donating groups of TC and transferred them to the PMS molecule. Thereafter, TC that lost electrons was oxidized and degraded, and the O–O bonds of PMS were destroyed by the transferred electrons to form S O 4 2 − and OH − . Moreover, O ⋅ 2 − and 1 O 2 were involved in TC degradation . TC degradation pathway was investigated through HPLC-MS analysis. These findings provide a promising strategy for the construction of catalysts for PMS and environmental remediation.
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ACS Applied Materials & Interfaces
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2020
·
IF 8.758
Ling Bai,YongLin Lei,Hao Huang,Yao Xiang
Mimicking human skin’s functions to develop intelligent materials have inspired extensive exploration in the design and synthesis of a novel device. However, how to simulate neuron function and integrate highly sensitive, positive perceptions and self-healing into one single material remains a challenge. Here, we prepared a recycled polyurethane (PU) with high tensile strength values (11.37 ± 0.03 MPa), high maximum elongation (1130 ± 11.59%), and high self-healing property (100% for 6 h at 25 °C) and a smart PU composite of polypyrrole-decorated carbon nanotubes with higher sensitivity. The smart composite can not only actively identify physical change such as strain, moisture, and temperature but also proactively detect various chemical environment changes such as acid, alkali, oxidant, and reductant (T: 25–90 °C, ΔR/R0 values were 0.1–1.6; strain: 10–150%, ΔR/R0 values were 2.5–27; 0.01–0.1 mol L–1 oxidant solutions, ΔR/R0 values were 0.66–0.75; 0.01–0.1 mol L–1 reductant solutions, ΔR/R0 values were 0.51–0.65; 0.1–0.5 mol L–1 acid solutions, ΔR/R0 values were 0.54–0.58; and 0.1–0.5 mol L–1 alkali solutions, ΔR/R0 values were 0.42–0.46). More importantly, the signal values of the smart composite can quickly return to the initial values after eliminating physical and chemical stimuli. The abovementioned features of the smart composite, the high physicochemical response, and significant restorability make it potentially possible to apply it in intelligent chemical manufacturing.
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JOURNAL OF COLLOID AND INTERFACE SCIENCE
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2020
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IF 7.489
Xiaogeng Feng,Xiangjie Bo,Liping Guo
Rational design and synthesis of multifunctional electrocatalysts with high-efficient activity and robust stability toward the oxygen reduction reaction (ORR), hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) are highly desirable, but remain a challenging step. Herein, a novel hollow bimetallic carbide/nitrogen-doped carbon nanotube (Co 6 Mo 6 C 2 @NCNT) is successfully synthesized through the simple pyrolysis of polypyrrole (PPy)-supported metal-organic framework (MOF) composite. Remarkable characteristics of the large surface area, hollow and porous structure, rich active sites and synergistic effect between Co 6 Mo 6 C 2 and NCNT arouse high catalytic efficiency. Notably, the Co 6 Mo 6 C 2 @NCNT presents excellent ORR catalytic activity (a high half-wave potential of 0.875 V vs . reversible hydrogen electrode (RHE) and diffusion-limited current density of 6.22 mA cm −2 ) via a four-electron pathway, together with outstanding stability and methanol tolerance over commercial Pt/C in 0.1 M KOH solution. The composite also exhibits superior HER performance, delivering a low overpotential of 122.14 mV at current density of 10 mA cm −2 , as well as good catalytic performance for OER in 1.0 M KOH solution. This work may provide some insight in design multifunctional electrocatalysts derived from MOF with advanced performance for sustainable energy technologies.
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CHEMICAL ENGINEERING JOURNAL
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2020
·
IF 10.652
Siyu Zhong,Huaizhi Liu,Donghai Wei,Jin Hu,Hang Zhang,Hongshuai Hou,Meixia Peng,Guanhua Zhang,Huigao Duan
An effective design of carbon materials with appropriate nanoarchitecture and optimized physicochemical property is critically demanded for superb lithium/sodium storage capacities. N-rich (up to 15.7%) hollow carbon nanotubes (NCNT) with long aspect ratio are well developed via a template method by exploring polypyrrole as the high nitrogen-containing carbon precursor. Owing to the hollow structure with large cavity and long aspect ratio, the NCNT exhibits Li + /Na + storage capability with favorable volume buffer and rapid ion and electron transfer at high rate, resulting in long-term cycling and high-rate property. Meanwhile, the high N content creates abundant active sites and extrinsic defects, facilitating the improved specific capacity and rate performance. Impressively, our NCNT-600 electrode displays a favorable reversible capacity of 132 mAh g −1 after 5000 cycles at 4000 mA g −1 for SIBs and 170 mAh g −1 after 2000 cycles at the same current for LIBs. Further quantitative kinetic analysis reveals the dominated capacitive contribution of Li + /Na + storage in NCNT, which is attributed to the porous hollow nanotubes and N-rich carbon with volume strain mitigation and enhanced electronic/ionic transfer capability. Given the cost-effectiveness and material sustainability, our work will shed light on the further design of other carbon-based materials for advanced energy storage devices.
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NEW JOURNAL OF CHEMISTRY
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2020
·Vol. 44
·期 27
·11808-11816
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IF 3.288
Shi-Yuan Zhang,Jing-Jing Ma,Hong-Lin Zhu,Yue-Qing Zheng
Syngas, as a necessary feedstock dependent on non-renewable fossil fuels, is a mixture of CO and H2, which could be prepared by a renewable strategy via electrochemical CO2 reduction in water electrolyte solutions. Herein, beaded Au@Co3O4 nanowire arrays (denoted as Au@Co3O4 NAs) were obtained by immersion in HAuCl4 solution with Co3O4 nanowire arrays. The Au@Co3O4 NAs exhibited outstanding electrochemical performance of producing syngas via tuning from 1 : 1 to 4 : 1 with controlling voltage. In addition, the Au@Co3O4 NAs showed better catalytic performance for the oxygen evolution reaction with an overpotential of 320 mV at a current density of 50 mA cm−2, along with a small Tafel slope of 75 mV dec−1 in 1 M KOH solution. The electrochemical performance of Au@Co3O4 NAs is obviously superior to Co3O4 NAs, which will open up a viable strategy for the design and fabrication of a bi-functional electrocatalyst for the overall reaction (CO2 + H2O → CO + H2 + O2).
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CHEMICAL ENGINEERING JOURNAL
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2020
·
IF 10.652
Yuexin Wang,Zhen Zhong,Yaseen Muhammad,Hui He,Zhongxing Zhao,Shuangxi Nie,Zhenxia Zhao
Engineering of monodentate ligands induced defects was proposed to modify NH 2 -MIL-88B(Fe) in order to promote its synergetic photo-Fenton catalytic degradation performance for acetamiprid (ACTM) as model neonicotinoid insecticides. Three monodentate ligands with different coordination groups (benzoic acid, pyrrole and pyrrole-2-carboxylic acid) were applied to in-situ induce ligand vacancies on NH 2 -MIL-88B(Fe). Effect of defect coordination mode on its photo-Fenton catalytic performance was investigated through the ACTM degradation reaction. Ligand defects on NH 2 -MIL-88B(Fe) would generate three merits: (1) it can modulate surface properties to enhance adsorption affinity towards ACTM; (2) it can introduce large amount of monodentate ligands and ligand vacancies in MOFs to promote light absorption and electron-hole separation capacity for photo-catalysis; (3) it can increase the amount of Fe Lewis acid sites to improve redox capacity of Fe 2+ /Fe 3+ for Fenton-catalysis. In this work, Pyrrole-2-carboxylic acid (Pac) was proved to introduce more monodentate ligands in MOFs and generate more ligand vacancies as well. As a result, ACTM can be easily captured by defective NH 2 -MIL-88B(Fe) and degraded by in-situ triggered oxidative reaction through the synergistic “photo-Fenton catalysis”. Performance measurements showed that Pac-MIL88(Fe) achieved 7.3 times higher adsorption rate and 5.5 times higher catalytic rate for ACTM than that of pristine MIL88(Fe). Moreover, total organic carbon (TOC) conversion reached 97.0% within only 90 min using Pac-MIL88(Fe) as photo-Fenton catalyst, showing 1.7 times higher than pristine MIL88(Fe). Thus, the in-situ fabrication of ligand defect-containing MIL88(Fe) can be foreseen of potential for designing new MOFs for wider practical applications.
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ANALYTICA CHIMICA ACTA
·
2020
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IF 5.977
Qi Kang,Qiao Zhang,Lixin Zang,Mengru Zhao,Xiaolan Chen,Dazhong Shen
Molecularly imprinting polymers (MIPs), as artificial antibodies with high recognition selectivity to template molecules, are widely used in various biosensors . To improve further the selectivity of MIPs-based photoelectrochemical (PEC) biosensors, we report a differential strategy using non-imprinted polymers (NIPs) as the reference. In a proof-to-concept example for the determination of dopamine (DA), MIPs and NIPs membranes were fabricated by electrochemical polymerization of polypyrrole membranes on the surface of graphene quantum dots (GQDs)/TiO 2 nanotubes (NTs). The photocurrent difference between the two PEC cells , MIPs@GQDs/TiO 2 NTs−Pt and NIPs@GQDs/TiO 2 NTs−Pt, was measured as the signal. As the non-specific adsorption of non-template molecules on the outside surface of MIPs and NIPs membranes is similar, the anti-interference ability for the determination of DA is much improved by using differential strategy. In the normal and differential PEC measurement models, 10.0 μM ascorbic acid is equivalent to 3.12 and 0.40 μM DA, respectively. Further, the smaller specific surface area in NIPs membrane was compensated by using a weight factor to correct the residual interference in a modified differential model. By using 10.0 μM ascorbic acid as the balance point, the presence of 10.0 μM H 2 O 2 , glutathione , uric acid or glucose is equivalent only to 0.090, 0.061,0.11 or 0.041 μM of DA, respectively, which are about 3–7% of their interference levels in the normal photocurrent model. The differential PEC method was applied in the determination of DA in serum samples in the linear range of 0.05–12.5 μM, with the detection limit of 0.018 μM.
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