Jun Hu

East China University of Science and Technology, Shanghai, Shanghai Shi, China

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Publications (77)184.29 Total impact

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    ABSTRACT: We present a rational design and synthesis of a novel porous pyridine-functionalized polycarbazole for efficient CO2 capture based on the density functional theory calculations. The task-specific polymer, generated through a one-step FeCl3-catalyzed oxidative coupling reaction, exhibits a superior CO2 uptake at 1.0 bar and 273 K (5.57 mmol g-1).
    No preview · Article · Feb 2016 · Chemical Communications
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    ABSTRACT: A task-specific mesoporous organic polymer (TSPOP) with unique features like good porosity and rich aromatic phenyl groups was facilely made and utilized as a promising adsorptive desulfurization (ADS) absorbent for the first time. The material exhibits an efficient saturated adsorption of dibenzothiophene (DBT), as high as 111.1 mg g−1. In addition, the intrinsic mesoporous skeleton of TSPOP gave rise to a facile incorporation of uniform Ag(I) species inside the network which facilitated the uptake of organosulfur compounds. A significantly higher saturated DBT adsorption for Ag(I)-loaded TSPOP [Ag(I)-TSPOP] reaches 203.7 mg g−1 via a multiple-site interaction. A detailed model study based on the density functional calculation provides a deeper understanding of the origin of this high activity. In addition to the π-π stacking between DBT and phenyl rings, there exists an additional π-complexation adsorption with Ag(I) ions, thus, significantly improving the DBT capture performance. This article is protected by copyright. All rights reserved.
    No preview · Article · Jan 2016 · AIChE Journal
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    ABSTRACT: A cost-effective hierarchical porous polymer poly-methylbenzene (PMB) was produced using the most common organic compound methylbenzene via a simple one-step Friedel-Crafts reaction. The large surface area as well as the proper mesoporosity ensured it to be a good substrate for loading metal species. After the impregnation of various metal species including PdCl2, Ag+, Fe3+, Ni2+, Zn2+, Cu2+ and Mg2+, a series of efficient desulfurization adsorbents of metal/PMB-x were fabricated. Among them, the PdCl2/PMB-40 adsorbent showed a most promising desulfurization performance with the DBT adsorption capacity as high as 25.97 mgS/g and a second-order desulfurization rate. Fourier transform infrared spectra (FTIR) measurements confirmed the desulfurization mechanism as the formation of S-M binding and π-complexation. Both high surface area of PMB and highly dispersed PdCl2 nanoparticles contributed to the good desulfurization performance.
    Full-text · Article · Dec 2015 · Fuel
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    ABSTRACT: High-throughput screening of desulfurization adsorbent has been implemented by introducing a classical density functional theory (CDFT). The screening is focused on the adsorption capacity of dibenzothiophene (DBT) in 458 types of metal–organic frameworks (MOFs). Comparing to the state of art desulfurization adsorbent, the best MOF for low concentration (BMLC) shows an uptake 27 times of HKUST-1 while the best MOF for high concentration (BMHC) shows an uptake twice of HKUST-1. Hierarchical porous structure has been found in BMLC and BMHC, respectively. According to the radial distribution function, a layered adsorption mechanism has been found in BMLC instead of BMHC; and the thermodynamic differences between BMLC and BMHC can be understood by this lamellar adsorption mechanism.
    No preview · Article · Dec 2015 · Chemical Engineering Science
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    ABSTRACT: The selective capture of CO2 under humid condition for the commercial adsorbents has always been a great challenge. Here, we come up with a simple and effective solution, i.e., fabrication a shell around the commercial zeolite particle which can dynamically hinder the diffusion of water molecules into the zeolite core to maintain its good CO2 capacity even in the presence of water. By a sol-gel coating process and a polyethylenimine (PEI) impregnation process, a series of 5A zeolite-based hybrids with a shell of mesoporous silica-supported-amine (5A@MSAs) were fabricated. The performance of CO2 separation from the simulated flue gas (with 15:85 v/v CO2/N2 and moisture) was investigated by TG and MS in a flow system. Among the obtained adsorbents, 5A@MSA-30 was demonstrated to be the best candidate for CO2 capture from the simulated humid flue gas, with the CO2 uptake as high as 5.05 mmol/g at 298 K. The results of 10 cyclic adsorption/desorption operation suggested that the PEI molecules can be stably holden in the mesoporous silica shell, resulting in a remained CO2 adsorption capacity. The amine modified zeolite not only maintained but also significantly promoted the ability of CO2 capture under humid condition; therefore, it would be a promising solution for the commercial adsorbents to capture CO2 in the presence of water.
    No preview · Article · Oct 2015 · Microporous and Mesoporous Materials
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    ABSTRACT: Microporous organic polymers (MOPs) are an emerging class of materials constructed from organic molecular building blocks. However, to design MOPs with surface functionalized porosities and high CO2 adsorption capacity is still a critical challenge. In this work, starting from different chemical functionalized triptycene monomers, including amino (–NH2), formyl (–CHO), acetyl (–COCH3) and nitro (–NO2) functional groups, we achieved a series of three-dimensional rigid framework of pre-functionalized triptycene-based polymers (TPPs) through a simple one-step Friedel–Crafts reaction. Moreover, alkyl-substituted amino groups were further incorporated into the network by the post-synthetic modification of amine pre-functionalized polymer TPP-1. The resulted microporous organic polymer TPP-1-NH2 presented an excellent CO2 adsorption capacity (4.17 mmol g−1 at 273 K, 1 bar) and a high CO2/N2 selectivity (43.6 at 273 K), which was ascribed to the predominant micropores and high CO2 isosteric adsorption heat of 41 kJ mol−1. Therefore, it is believed that these MOPs with high physicochemical stability are promising candidates for selective CO2 capture by employing this functionalized modification method.
    No preview · Article · Sep 2015 · Microporous and Mesoporous Materials
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    ABSTRACT: Metal organic framework/Graphite oxide (MOF/GO) composites have been greatly concerned for their increasing applications. We proposed an in-situ interfacial growth method induced by the Pickering emulsion strategy to produce Cu3(BTC)2/GO composites, in which GO was demonstrated to be a promising stabilizer for producing the Pickering emulsion, and provided a large interface area for the in-situ growth of Cu3(BTC)2 nanoparticles. Hence, when Cu3(BTC)2/GO composites were used as adsorbents for CO2 capture from the simulated flue gas in the presence of the humidity, it showed significant improvements in both thermodynamic and dynamic ways. Since most of H2O molecules were adsorbed on the highly exfoliated GO sheets in Cu3(BTC)2/GO-m, CO2 uptake reached 3.30 mmol/g after exposing to the simulated flue gas for 60 min and remained unchanged for prolonging to 120 min. This highlighted its potential application for real CO2 capture. More importantly, the in-situ interfacial growth of nanoparticles induced by Pickering emulsions would be a promising strategy for designing and fabrication the nanocomposites.
    No preview · Article · Jun 2015 · Langmuir
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    ABSTRACT: Most organic dyes dissipate their excitation energy in the aggregated state because of “aggregation caused quenching” effect, deteriorating their application in optoelectronic devices. To prevent “aggregation caused quenching” effect, we incorporate a dye-based fluorophore into a porous organic polymer skeleton because porosity would breed the spatial isolation of fluorophores to maintain its emission. Tuning the fraction of fluorophores in the skeleton of FL-SNW-DPPs would range the emission color covering from red to blue in both solid-state and suspension. More importantly, the combination of fluorescence and porosity of FL-SNW-DPPs would provide more space to transduce the molecular interaction between adsorbed analytes and fluorophores to the detectable changes in light emission, leading to the fluorescence-off or fluorescence-on detection of electron-deficient or electron-rich analytes.
    No preview · Article · May 2015
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    ABSTRACT: A facile template-free strategy for the synthesis of mesoporous phenolic polymers with attractive porosities, nitrogen-containing functionalities, and intrinsic hydrophilic skeletons is presented. The resultant polymer has a high BET surface area (548 m2 g-1) and mesopore size (13 nm) and exhibits superior glycopeptide-capturing performance, thus, revealing the potential application of mesoporous polymers in highly selective glycopeptide enrichment. This general capture protocol may open up new opportunities for the development of glycoproteomes.
    Full-text · Article · May 2015 · ACS Macro Letters
  • Jie Gao · Jian Xu · Shixian Wen · Jun Hu · Honglai Liu
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    ABSTRACT: Silver nanoparticle is an important catalyst for many chemical reactions and usually demands complex synthesis technology. In this work, a convenient and efficient plasma-assisted synthesis method was proposed to synthesize a new type of composite catalyst with Ag nanoparticles immobilized in 3D mesoporous cellular foams (MCFs) of silica. The plasma treatment under O2 atmosphere provided more activated silanol groups on the surface of MCF for the immobilization of Ag nanoparticles. The properties of immobilized Ag nanoparticles, such as smaller average size, higher loading, and better dispersion state greatly improved the reaction rate of the catalytic reduction of 4-nitrophenol (4-NP). Among them, with an average size of 6.0 nm and 2.6 wt% immobilized Ag nanoparticles, the catalyst MCF-100-Ag-0.01 showed the best catalytic activity for the reduction of 4-NP, that the apparent reduction rate constant was as large as 2.66 × 10−2 s−1, and the turnover frequency coefficient was as extremely high as 8.97 × 1018 molecules g−1 s−1. The MCF-n-Ag-m composites could be expected as attractive catalysts for many other catalytic reactions. More importantly, this plasma-assisted synthesis approach could be a convenient way for the synthesis of highly active catalysts by immobilizing various types of metal nanoparticles in porous materials.
    No preview · Article · May 2015 · Microporous and Mesoporous Materials
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    ABSTRACT: This article is about resettled Afghan Hazaras in Australia, many of whom are currently undergoing a complex process of transition (from transience into a more stable position) for the first time in their lives. Despite their permanent residency status, we show how resettlement can be a challenging transitional experience. For these new migrants, we argue that developing a sense of belonging during the transition period is a critical rite of passage in the context of their political and cultural identity. A study of forced migrants such as these, moving out of one transient experience into another transitional period (albeit one that holds greater promise and permanence) poses a unique intellectual challenge. New understandings about the ongoing, unpredictable consequences of ‘transience’ for refugee communities is crucial as we discover what might be necessary, as social support structures, to facilitate the process of transition into a distinctly new environment. The article is based on a doctoral ethnographic study of 30 resettled Afghan Hazara living in the region of Dandenong in Melbourne, Australia. Here, we include four of these participants’ reflections of transition during different phases of their resettlement. These reflections were particularly revealing of the ways in which some migrants deal with change and acquire a sense of belonging to the community. Taking a historical view, and drawing on Bourdieu’s notion of symbolic social capital to highlight themes in individual experiences of belonging, we show how some new migrants adjust and learn to ‘embody’ their place in the new country. Symbolic social capital illuminates how people access and use resources such as social networks as tools of empowerment, reflecting how Hazara post-arrival experiences are tied to complex power relations in their everyday social interactions and in their life trajectories as people in transition. We learned that such tools can facilitate the formation of Hazara migrant identities and are closely tied to their civic community participation, English language development, and orientation in, as well as comprehension of local cultural knowledge and place. This kind of theorization allows refugee, post-refugee and recent migrant narratives to be viewed not merely as static expressions of loss, trauma or damage, but rather as individual experiences of survival, adaptation and upward mobility.
    No preview · Article · Mar 2015 · RSC Advances
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    ABSTRACT: For the real industrial process of CO2 capture, it is still a great challenge for adsorbents to exhibit excellent CO2 adsorption capacity in the presence of water. By combining a pre-seeding process and a two-step temperature controlling crystallization, zeolitic imidazolate framework (ZIF-8) shell is introduced on the commercial zeolite adsorbent (5A) core to produce a series of 5A@ZIF-8 composites with an enhanced surface hydrophobicity. Each 5A@ZIF-8 composite exhibits a dynamic hydrophobic hindrance effect for the separation CO2 from the simulated humid flue gas (15% CO2 and 90% humidity at 298 K). Among them, the CO2 adsorption capacity and the CO2/H2O selectivity of 5A@ZIF-8(I) can be as high as 2.67 mmol g-1 and 6.61 at the optimized adsorption time of 10 min. More importantly, over 10 adsorption-desorption cycles, there is almost no degradation of adsorption performance. Therefore, the novel strategy of utilizing the dynamic hydrophobic hindrance effect through a core-shell structure would be a good solution for improving the CO2 separation performance in practical applications.
    Preview · Article · Mar 2015
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    ABSTRACT: In through-wall indication of a moving human target in enclosed structures, a shadow effect because of the human target blocking parts from illumination on the back wall will emerge, referred to as a “ghost” in indication results. The shadow ghost moves as the human target does, which makes causal change detection (CD) invalid to separate them. To mitigate the shadow ghost, we analyze its differences from the moving human target. Based on the difference that the illumination is only blocked in partial channels of the multiple-input–multiple-output (MIMO) array while target echoes exist in most channels and the fact that shadow ghosts overlap more between successive indication results than the imaged targets as a result of their larger size, we proposed a mitigation method including a coherence factor and noncausal CD processing. Through-wall experiments via a MIMO through-wall imaging radar validate the proposed method.
    No preview · Article · Mar 2015 · IEEE Geoscience and Remote Sensing Letters
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    ABSTRACT: Plasma technology, an efficient and important approach for the surface modification, has been widely adopted for the treatment on the exposed surface of planar substrates. In this work, plasma treatment was demonstrated to be an effective way for the internal surface modification in one-dimensional channels of mesoporous SBA-15 particles, which is not a general planar substrate. Upon the plasma treatment in O-2 atmosphere, the silanol groups on the surface of channels were intensively activated, as a result, large amounts of amine groups (2.56 mmol (APTS)/g(sample)) can be effectively grafted within a very short time (2 h). The highly dispersed amine groups inside the channels can be facilely revealed by the location of in-situ coordinated Ag nanoparticles. Moreover, the amine-modified SBA-15 via the plasma treatment exhibited a better CO2 adsorption capacity (1.26 mmol/g) comparing with the traditional amine-modified SBA-15. Thus, our new approach may pave the way towards the rational modification and effective activation for porous materials, which would be meaningful for functionalization applications.
    No preview · Article · Jan 2015 · Microporous and Mesoporous Materials
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    ABSTRACT: Hierarchical porous metal organic framework (MOF) composites are highly demanded because they can keep the high activity and good transport property simultaneously. A novel method of ionic liquidassisted growth of Cu-3(BTC)(2) on graphene oxide (GO) sheets was proposed and applied to improve both CO2 adsorption capacity and adsorption rate. Three ionic liquids (ILs) of triethylene tetramine acetate (TETA-Ac), triethylene tetramine tetrafluoroborate (TETA-BF4) and 1-butyl-3-methylimidazolium tetrafluoroborate ([Bmim]BF4) were used to investigate the effects of cations and anions of ILs on the structure of GO-IL/MOF composite. With amine or imidazole cations adsorbed at the surface of GO and the contrary anions closely attached, GO-ILs can provide a lot of active sites for the absorption of Cu2+ cations through the coordination. Just like a bridge, ILs assisted the initial growth of the first seed layer of Cu-3(BTC)(2) on the surface of GO. Among various GO-IL/MOP composites, GO-TAc/MOF-60 sample showed a superimposed structure, which lead to more accessible adsorption activity sites and shorten the transfer distance. Also, the GO sheets in GO-IL/MOF provide channels for faster transfer. It showed a high CO2 adsorption capability of 5.62 mmol/g at 25 degrees C and 100 kPa, and a high CO2 kinetic separation performance as well. More importantly, the composite presented a quite good cyclic adsorption/desorption stability. The relations between the specific structures of the composites and the CO2 adsorption behaviors were tentatively demonstrated to reveal a convenient way for designing and fabricating hierarchical MOF composites.
    No preview · Article · Dec 2014 · Microporous and Mesoporous Materials
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    ABSTRACT: Thiazolothiazole-linked porous organic polymers have been synthesized from a facile catalyst-free condensation reaction between aldehydes and dithiooxamide under solvothermal condition. The resultant porous frameworks exhibit a highly selective uptake of CO2 over N2 at ambient conditions.
    No preview · Article · Oct 2014 · Chemical Communications
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    ABSTRACT: TiO2 microspheres containing carbon have been synthesized viaa one-pot hydrothermal process using CTAB as the mesoporous template and nanoparticle stabilizer and Ti(SO4)2 and sucrose as titanium and carbon precursors, respectively. Through well designed calcinations, TiO2 microspheres with various amounts of carbon-residue, such as core/shell C@TiO2, hollow neat H–TiO2, and hollow C/TiO2 composites, are obtained. When these microspheres are used as anode materials for lithium ion batteries, the lithium storage performance is significantly influenced by the structure and carbon-residue. With a thin shell of TiO2 nanoparticles and carbon-residue, the capacity of hollow C/TiO2 composites maintains at 143.3 mA·h·g− 1 at 0.5 C (83.5 mA·g− 1) after 100 cycles. Moreover, after high rate charge/discharge cycles from 0.2 C to 20 C and back to 0.2 C again, the reversible capacity recovers atas high as 195.1 mA·h·g− 1 with respect to its initial value of 205.0 mA·h·g− 1. The results of cycle voltammograms and electrochemical impedance spectroscopy further reveal that Li+ insertion/extraction processes are reversible, and the diffusion coefficient of Li+ in the hollow C/TiO2 composites is much higher than those of others, because the hollow structure can act as the ion-buffering reservoir and facilitate Li+ transfer from both sides of the shell, and the carbon-residue in the shell improves the conductivity as well.
    No preview · Article · Oct 2014 · Chinese Journal of Chemical Engineering
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    ABSTRACT: Mixed micelle template approach is one of the most promising synthesis methods for hierarchical porous materials. Although considerable research efforts have been made to explore the formation mechanism, an explicit theoretical guidance for appropriately choosing templates is still not available. We found that the phase separation occurring in the mixed micelles would be the key point for the synthesis of hierarchical porous materials. Herein, the pseudo-phase separation theory for the critical micelle concentration (cmc) combining with the Flory-Huggins model for the chain molecular mixture were employed to investigate the properties of mixed surfactant aqueous solution. The cmc values of mixed surfactant solutions were experimentally determined to calculate the Flory-Huggins interaction parameter between two surfactants, χ. When χ is larger than the critical value,χc, the phase separation would occur within the micellar phase, resulting in two types of mixed micelles with different surfactant compositions, and hence different sizes, which could be used as the dual-template to induce bimodal pores with different pore sizes. Therefore, the Flory-Huggins model could be a theoretical basis to judge whether the mixed surfactants were the suitable templates for inducing hierarchical porous materials. We chose cetyltrimethylammonium bromide (CTAB) and n-octylamine (OA) as a testing system. The phase separation behavior of the mixed solutions, as well as the successful synthesis of hierarchical porous materials by this dual-template indicated the feasibility of preparing hierarchical porous materials based on the concept of phase separation of the mixed micelles.
    Full-text · Article · Sep 2014 · Langmuir
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    ABSTRACT: The world becomes more stringent on keep lowering the sulfur concentrations in fuels. To fulfill this expectation, a new type of magnetic desulfurization adsorbent of Fe3O4@PAA@MOF-199 was designed and fabricated by a facile two-step assembly approach, in which PAA inventively acted like a bridge to incorporate different amounts of the magnetite Fe3O4 into MOF-199 crystal matrix. Fe3O4@PAA@MOF-199s were demonstrated to be efficient adsorbents for the removal of S-compounds of thiophene, benzothiophene (BT) and dibenzothiophene (DBT) from a model fuel, and the sulfur saturated adsorption capacity followed the order of DBT > BT > thiophene. The magnetization of Fe3O4@PAA@MOF-199s insured the adsorbents a good performance in magnetic separation. The relative high adsorption capacity, the separation efficiency, as well as the stable recyclability indicated that magnetic Fe3O4@PAA@MOF-199 would be a promising adsorbent in adsorptive desulfurization.
    Full-text · Article · Aug 2014 · RSC Advances

  • No preview · Conference Paper · Jul 2014

Publication Stats

622 Citations
184.29 Total Impact Points

Institutions

  • 2006-2015
    • East China University of Science and Technology
      • School of Chemistry and Molecular Engineering
      Shanghai, Shanghai Shi, China
  • 2013-2014
    • National University of Defense Technology
      • College of Electronic Science and Engineering
      Ch’ang-sha-shih, Hunan, China