Institute of Chemistry
Changchun Institute of Applied Chemistry, Chinese Academy Of SciencesNot a member yet
23443 research outputs found
Sort by
Cheap carbon black-based high-performance electrocatalysts for oxygen reduction reaction
No full textA family of cheap carbon black based Fe-N-x/C electrocatalysts with superhigh-performance for oxygen reduction reaction (ORR) were synthesized. The one with Fe 10 wt% and N 1.57 wt% shows the best performance. The activity order of different active sites for ORR was revealed firstly: Fe-N-4/2-C > Fe-4-N-C > N-C >> Fe-4-C approximate to C
One-pot atom-efficient synthesis of bio-renewable polyesters and cyclic carbonates through tandem catalysis
No full textOne-pot synthesis of well-defined bio-renewable polyesters and cyclic carbonates in high yields was successfully realized for the first time by way of a tandem reaction using metal salen complexes as catalysts. This tandem process offered unprecedented opportunities for the atom-efficient production of two relevant compounds
Controllable synthesis of hollow mesoporous silica particles by a facile one-pot sol-gel method
No full textA simple and facile one-pot sol-gel method is proposed for the fabrication of hollow mesoporous silica particles. Both the particle size and the shell thickness can be well controlled by moderately tuning some experimental parameters
Covalent Entrapment of Cobalt-Iron Sulfides in N-Doped Mesoporous Carbon: Extraordinary Bifunctional Electrocatalysts for Oxygen Reduction and Evolution Reactions
No full textTo alleviate the kinetic barriers associated with ORR (oxygen reduction reaction) and OER (oxygen evolution reaction) in electrochemical systems, efficient nonprecious electrocatalysts are urgently required. Here we report a facile soft-template mediated approach for fabrication of nanostructured cobaltiron double sulfides that are covalently entrapped in nitrogen-doped mesoporous graphitic carbon (Co(0.5)Fe(0.)5S@N-MC). Notably, with a positive half-wave potential (0.808 V) and a high diffusion-limiting current density, the composite material delivers unprecedentedly striking ORR electrocatalytic activity among recently reported nonprecious late transition metal chalcogenide materials in alkaline medium. Various characterization techniques, including X-ray absorption spectroscopy, X-ray photoelectron spectroscopy, and X-ray diffraction, are conducted to elucidate the correlation between structural features and catalytic activities of the composite. Moderate substitution and well-dispersion of iron in bimetallic sulfide composites are believed to have positive effect on the adsorption and activation of oxygen-containing species, thus leading to conspicuous ORR and OER catalytic enhancement compared to their monometallic counterparts. Besides, the covalent bridge between active sulfide particles and mesoporous carbon shells provides facile pathways for electron and mass transport. Beneficially, the intimate coupling interaction renders prolonged electrocatalytic performances to the composite. Our results may possibly lend a new impetus to the rational design of bi- or multimetallic sulfides encapsulated in porous carbon with improved performance for electrocatalysis and energy storage applications
Enhanced proton conductivity of sulfonated poly(p-phenylene-co-aryl ether ketone) proton exchange membranes with controlled microblock structure
No full textA new series of sulfonated poly(p-phenylene-co-aryl ether ketone)s (s, m, I-SPP-co-PAEKs) microblock polymers containing different hydrophobic units with precisely defined lengths have been prepared via the nickel (0) catalyzed coupling copolymerization and characterized to act as proton exchange membranes. By controlling the length and chemical structure of the hydrophobic units in the copolymers, these novel microblock polymers can exhibit well-developed nanophase morphologies and large length-scale of the ionic channels, resulting in the improvement of the proton conductivity in both the wet and dry state. Moreover, the membrane I-SPP-co-PAEK 1.80 with the largest hydrophobic micro-block length shows high proton conductivity, excellent dimensional stability, low glass-transition temperature (Tg), good oxidative stability and superior cell performance. (C) 2015 Elsevier B.V. All rights reserved
Carbon supported trimetallic nickel-palladium-gold hollow nanoparticles with superior catalytic activity for methanol electrooxidation
No full textIn this paper, Ni nanoparticles (NPs) are prepared in an aqueous solution by using sodium borohydride as reducing agent. With Ni NPs as the sacrificial template, hollow NiPdAu NPs are successfully prepared via partly galvanic displacement reaction between suitable metal precursors and Ni NPs. The as-synthesized hollow NiPdAu NPs can well dispersed on the carbon substrate. Transmission electron microscopy, X-ray diffraction and inductively coupled plasma mass spectrometry are taken to analyze the morphology, structure and composition of the as-synthesized catalysts. The prepared catalysts show superior catalytic activity and stability for methanol electrooxidation in alkaline media compared with commercial Pd/C and Pt/C. Catalysts prepared in this work show great potential to be anode catalysts in direct methanol fuel cells. (C) 2015 Elsevier B.V. All rights reserved
Targeted delivery of cisplatin by LHRH-peptide conjugated dextran nanoparticles suppresses breast cancer growth and metastasis
No full textThe metastasis of breast cancer is the leading cause of cancer death in women. In this work, an attempt to simultaneously inhibit the primary tumor growth and organ-specific metastasis by the cisplatin-loaded LHRH-modified dextran nanoparticles (Dex-SA-CDDP-LHRH) was performed in the 4T1 orthotopic mammary tumor metastasis model. With the rationally designed conjugation site of the LHRH ligand, the Dex-SA-CDDP-LHRH nanoparticles maintained the targeting function of LHRH and specifically bound to the LHRH-receptors overexpressed on the surface of 4T1 breast cancer cells. Therefore, the Dex-SA-CDDP-LHRH nanoparticles exhibited improved cellular uptake and promoted cytotoxicity, when compared with the non-targeted Dex-SA-CDDP nanoparticles. Moreover, both the non-targeted and targeted nanoparticles significantly decreased the systemic toxicity of CDDP and increased the maximum tolerated dose of CDDP from 4 to 30 mg kg(-1). Importantly, Dex-SA-CDDP-LHRH markedly enhanced the accumulation of CDDP in the injected primary tumor and metastasis-containing organs, and meanwhile significantly reduced the nephrotoxicity of CDDP. Dose-dependent therapeutic effects further demonstrated that the CDDP-loaded LHRH-decorated polysaccharide nanoparticles significantly enhanced the antitumor and antimetastasis efficacy, as compared to the non-targeted nanoparticles. These results suggest that Dex-SA-CDDP-LHRH nanoparticles show great potential for targeted chemotherapy of metastatic breast cancer. (C) 2015 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved
Growth of Hydrophilic CuS Nanowires via DNA-Mediated Self-Assembly Process and Their Use in Fabricating Smart Hybrid Films for Adjustable Chemical Release
No full textFacile growth of CuS nanowires through self-assembly and their application as building blocks for near-infrared light-responsive functional films have been demonstrated. It is found that DNA is a key factor in preparing the CuS material with defined nanostructure. An exclusive oriented self-aggregate growth mechanism is proposed for the growth of the nanowires, which might have important implications for preparing advanced, sophisticated nanostructures based on DNA nanotechnology. By employing the hydrophilic CuS nanowire as an optical absorber and thermosensitive nanogel as guest reservoir inside alginate film, a new platform for the release of functional molecules has been set up. In vitro studies have shown that the hybrid film possesses excellent biocompatibility and the release rate of chemical molecules from the film could be controlled with high spatial and temporal precision. Our novel approach and the resulting outstanding combination of properties may advance both the fields of DNA nanotechnology and light-responsive devices
Facile synthesis of self-host functional iridium dendrimers up to the fourth generation with N-phenylcarbazole-based polyether dendrons for non-doped phosphorescent organic light-emitting diodes
No full textA facile synthesis has been demonstrated for the first time to construct self-host functional Ir-cored dendrimers up to the fourth generation on the basis of a newly developed polyether dendron, where the N-phenylcarbazole (NPC) moiety is used as the basic building block instead of benzene to improve charge transport whilst keeping the ease of preparation. With the growing generation number, the dendrimer size can be well tuned in a wide range of 4-10 nm. The obtained fourth generation dendrimer 45NPC-G4 is the largest Ir complex ever reported so far, having a diameter up to 10 nm and a molecular weight as high as 15.9 kDa. Most interestingly, the performance of non-doped phosphorescent organic light-emitting diodes (PhOLEDs) is found to be greatly dependent on the molecular size. For example, 9NPC-G2 (R approximate to 30 angstrom) reveals the best luminous efficiency as high as 50.5 cd A(-1) (56.6 lm W-1, 14.8%), whereas the efficiency of 45NPC-G4 (R approximate to 50 angstrom) sharply drops to 10.5 cd A(-1) (5.6 lm W-1, 3.4%). The results suggest that an appropriate size of 6 +/- 2 nm is desirable to balance the dilemma between luminescence quenching and charge transport, and thereby realize highly efficient non-doped PhOLEDs
多孔碳基复合电极材料的制备及其电化学性能研究
No full text高容量、长寿命、高安全性电极材料的开发是下一代锂离子电池研究的重点，是加速其在便携式电子设备、清洁能源储备、混合动力汽车等领域广泛应用的关键技术。针对目前过渡金属氧化物基锂离子电池负极材料充放电循环及倍率性能差的问题，本论文设计了一系列具有多孔结构的碳材料，采用超临界二氧化碳(scCO2)膨胀乙醇沉积技术，在多孔结构的碳材料表面包覆过渡(复合)金属氧化物纳米粒子，制备了一系列具有孔结构的碳材料及其与过渡金属氧化物复合的高性能电极材料。主要内容如下： (i) 设计一种同时具有大孔和介孔的三维结构碳材料(3DHPC)作为基底，采用scCO2沉积方法，在其表面均匀沉积一层Fe3O4纳米粒子，制备了一种新型结构的锂离子电池负极材料——Fe3O4/3DHPC复合材料。实验中3DHPC碳基底无需预氧化处理即可直接使用，借助于scCO2溶剂作用，Fe3O4粒子可均匀的负载到3DHPC材料上，Fe3O4的...The development of electrode materials with high capacity, long life, and high safety is an important issue in the study of the next generation of lithium ion batteries (LIBs), which is the key technology for accelerating development of portable electronic devices, clean energy reserves and hybrid electric vehicles. Based on the problems of the worse cycling performance and rate capability of transition metal oxide-based anode materials of LIBs, we designed a series of porous carbon materials, and deposited nanometer-sized transition metal oxide particles on their surfaces with the assistance of supercritical carbon dioxide (scCO2) expanded ethanol deposition technique. As a result, a series of high-performance electrode materials composing of transition metal oxide and porous carbon mater..