ACS Applied Materials & Interfaces
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2014
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IF 5.9
Jiantong Hu,Zhongxin Chen,Mengxiong Li,Xiaohui Zhou,Hongbin Lu
Highly efficient heterogeneous catalysts are desired for the development of new energy storage materials. The rational choice and use of capping ligands are of significant importance for performance optimization of metal nanoparticle (NP) catalysts. By exploiting amine-rich polyethylenimine (PEI) and graphene oxide (GO) as a NP support, we demonstrate that as a capping ligand, PEI deposited on GO provides a novel pathway able to simultaneously control the morphology, spatial distribution, surface active sites of cobalt (Co) NPs, and remarkably enhances their catalytic properties for the hydrolytic dehydrogenation of ammonia borane (AB). Such a synergistic effect enables the synthesized PEI-GO/Co catalysts to reveal extremely high dehydrogenation activities under atmosphere condition. A total turnover frequency of 39.9 molH2 min–1 molCo–1 and an apparent activation energy of 28.2 kJ mol–1 make the catalytic performance of these PEI-GO/Co catalysts comparable to those of noble metal-based catalysts, including bimetallic and multimetallic catalysts.
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PubMed
高影响因子
JOURNAL OF POLYMER RESEARCH
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2013
·Vol. 20
·期 10
·1-9
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IF 2.019
Liu Pengqing,Zeng Luxian,Ye Guangdou,Xu Jianjun
A series of co-polyarylates containing m -aryl ether units were synthesized from bisphenol A, 1,3-bis(4′-formylchloridephenoxy)benzene and terephthaloyl chloride via interfacial polycondensation in order to improve the processability of the bisphenol A-based polyarylate (U-polymer). The structure and properties of the co-polyarylates were characterized using infrared spectra, differential scanning calorimety, thermogravimetric analyses, wide angle x-ray diffraction and solubility testing, etc. The results show that the introduction of the asymmetry and flexible m -aryl ether units could improve the solubility obviously, but the solubility parameter of the co-polyarylate almost keeps a constant with changing the content of m -aryl ether units. As the content of m -aryl ether unit increases, the crystallization ability of the polyarylate weakens, meanwhile, the melting temperature shifts to low temperature as expected and the melting enthalpy reduces. When the content of the m -aryl ether units is higher than 60 %, the co-polyarylates become amorphous polymers. Moreover, there is almost no reduction of the thermal stability with increasing the content of the m -aryl ether units. In addition, the stability of each chemical bond of the co-polyarylate to thermal decomposition was systematically studied by means of pyrolysis-gas chromatography/mass spectrometry, and the thermal decomposition mechanism of the co-polyarylate was obtained.
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高影响因子
RSC Advances
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2013
·Vol. 3
·期 43
·20922-20929
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IF 2.562
Jingjing Huang,Dong Wang,Ying Lu,Mufang Li,Weilin Xu
Antifouling nanofibers with zwitterionic materials on surfaces that can prevent the nonspecific adhesion of biomolecules and microorganism are in demand for high efficiency biosensors and affinity membranes. The functionalization of zwitterionic sulfobetaine on surfaces of PVA-co-PE nanofiber membrane via click chemistry is performed employing two synthesis routes and reported in this paper. PVA-co-PE nanofiber membranes were activated with cyanuric chloride, and then surface functionalized with sodium azide or 2-propynylamine to prepare “clickable” nanofibers with azide or alkynyl groups, respectively. The zwitterionic sulfobetaine was finally “clicked” onto PVA-co-PE nanofiber membranes. The successful surface functionalizations of PVA-co-PE nanofiber membrane were confirmed with FTIR-ATR, Raman spectroscopy, XPS and EDS. The analysis of element composition using XPS indicated that alkynylation of activated PVA-co-PE nanofiber membranes can “click” more sulfobetaines on nanofiber surfaces than surface azidation. SEM results showed that functionalized PVA-co-PE nanofiber membranes maintained well-defined nanofibrous morphology. PVA-co-PE nanofiber membranes with zwitterionic sulfobetaine demonstrated excellent antifouling performance by effectively resisting bovine serum albumin (BSA) protein adsorption.
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高影响因子
JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS
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2013
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IF 2.56
Xiangbo Ji,Jianguo Deng,Bin Kang,Hui Huang,Xin Wang,Wei Jing,Tao Xu
Yttrium aluminum garnet (YAG) nano-precursors were synthesized by urea homogeneous co-precipitation. The morphology and crystalline phase, particularly the in situ evolved gases of as-synthesized precursors during the thermal decomposition, were characterized and verified. The evolved NH 3 , H 2 O, and CO 2 gases can be observed below 600 °C. The released NO 2 gas was observed at 202 °C, 500 °C and 885 °C, which suggests that N O 3 − existed in the precursor with three different forms. Furthermore, the evolved SO 2 gas was detected above 850 °C due to desulfurization. Phase-pure YAG can be obtained when the precursor was calcined at 900 °C. The particle size increases with increasing calcination temperature. The powders calcined at 1100 °C were well dispersed and had an average grain size of 100 nm owing to the decomposition of S O 4 2 − at high temperatures.
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SEPARATION AND PURIFICATION TECHNOLOGY
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2016
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IF 3.299
Qizhou Dai,Jiazhong Zhou,Mili Weng,Xubiao Luo,Daolun Feng,Jianmeng Chen
This study presents an electrochemical method for the degradation of metronidazole (MNZ) in aqueous solution with novel PbO 2 electrode, which was prepared via electrodeposition in nitrate solution. The influencing factors on electrochemical decomposition of pollutants were evaluated and the removal of MNZ and chemical oxygen demand (COD) reached 78.09% and 21.77% after 120 min treatment under the optimal conditions with the concentration of supporting electrolyte, the initial concentration of MNZ, the pH and the current density were 0.10 mol/L, 100 mg/L, 6.4 and 10 mA/cm 2 , respectively. Then, the Co doped PbO 2 electrodes were prepared and used to degrade MNZ under the optimal conditions. Relatively good performance was achieved when the molar ratio of Pb and Co was 100:1. Compared to pure PbO 2 electrode, the steady-state polarization curves and cyclic voltammetry analysis showed that 1.0% Co-PbO 2 electrode had a higher oxygen evolution potential and greater current of reduction and oxidation peaks, which increased the electrochemical activity and decreased the energy consumption. Finally, based on the intermediate products identified by IC and GC/MS, the main degradation pathway of MNZ was proposed including ring open, denitrification and radical reactions.
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高影响因子
NEW JOURNAL OF CHEMISTRY
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2016
·Vol. 40
·期 6
·5231-5237
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IF 3.277
Zhangping Xu,Wenjing Wang,Jingchuan Wu,Sai Mi,Jianming Zheng,Chunye Xu
A pair of solution-processable electrochromic polymers poly(2,3-bis(3,4-bis(dodecyloxy)phenyl)-5,8-bis(2,3-dihydrothieno[3,4-b][1,4]dioxin-5-yl)quinoxaline) (P1) and poly(3,4-di(2-ethylhexyloxy)thiophene-co-3,4-dibutoxythiophene) (P2) were designed and synthesised through a chemical oxidative polymerization and copolymerization approach. According to colour mixing theory, the two polymers with complementary colours (green for P1 and purple-red for P2) were utilised to create black-to-transmissive switching films via co-processing from a solution containing them in an appropriate mass ratio. The films exhibit a deep black colour, moderate optical contrast and robust stability. This method and the films with favourable electrochromic performances could be employed for the realization of potential large area electrochromic device applications.
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高影响因子
MATERIALS RESEARCH BULLETIN
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2016
·
IF 2.435
Tara Larsson,Ting Shuai Li,Min Xu,Ida Fransson,Guangsen Yu,Martin Andersson,Baihai Li,Bengt Sunden
In this study, we co-fabricated the Ni-based nanofibers using an electrospinning technique. The effects of viscosity, applied voltage and distance from needle to the collection plate on the fiber morphology were investigated. The fibers were sintered at temperatures ranging from 350 °C to 1200 °C and the results indicated that the crystallization was completed at 800 °C and the particle size increased with the temperature. The porosity of nanostructure can reach over 50% before reduction of the nickel oxide, which increased firstly with the temperature and then decreased over 800 °C. The nanocrystallization of an anode was helpful to maximize the electrochemical reaction sites for restraining the activation polarization and also to enlarge pores for rapid gas diffusion in fuel cells.
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高影响因子
POLYMER
·
2016
·
IF 3.586
Hongyan Yao,Kaixiang Shi,Ningning Song,Na Zhang,Pengfei Huo,Shiyang Zhu,Yunhe Zhang,Shaowei Guan
A novel diamine monomer 3,3′-Bis(2,3,5,6-tetrafluoro-4-vinylphenoxy)biphenyl-4,4′-diamine (TFVBPA) bearing double hydrophobic cross-linkable tetrafluorostyrol side-groups has been successfully synthesized via a nucleophilic substitution reaction . A series of cross-linked highly sulfonated co-polyimide (CSPIy-TFVBPAx) membranes with ion-exchange capacity (IEC) values ranging from 2.27 to 2.44 meq. g −1 have been prepared from this monomer . The CSPIy-TFVBPAx membranes show excellent comprehensive properties, especially the high proton conductivity (0.135–0.190 S cm −1 at 80 °C), low water uptake (60.9–76.7% at 80 °C) and swelling ratio (14.2–19.6% at 80 °C). Moreover, the CSPIy-TFVBPAx membranes also exhibit outstanding thermal stability (5% weight loss temperature exceed 320 °C) and excellent hydrolytic stability. The results indicate that the CSPIy-TFVBPAx membranes are promising candidates for proton exchange membranes in fuel cell applications .
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JOURNAL OF ALLOYS AND COMPOUNDS
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2016
·
IF 3.014
Yitao Wu,Yinyan Gong,Jiaqi Liu,Zhen Zhang,Yan Xu,Hui Ren,Can Li,Lengyuan Niu
B and Y doped titanium dioxides (TiO 2 ) photocatalysts were synthesized by a sol-gel method followed by calcination . It is observed that the photodegradation efficiency of B and Y co-doped TiO 2 is twice that of undoped sample. To explore the underlining mechanism, x-ray diffraction, Raman, scanning electron microscope, x-ray photoemission, and UV–Vis diffuse reflectance spectroscopy measurements have been carried out to investigate the effect of B and Y doping on the structural, electronic, and optical properties of titania. Experimental observations revealed that in TiO 2 lattice Y 3+ ions tend to replace Ti 4+ ions while B 3+ ions occupy the interstitial sites. The incorporation of interstitial boron dopants will create oxygen vacancies ( Ov ·· ) and reduce Ti 4+ to Ti 3+ to form [ Ov ·· -Ti 3+ ] + complex, which traps the carriers and prolongs carrier lifetime. Moreover, Y 3+ ions can trap the photo-excited electrons to form Y 2+ ions, which will then react with the absorbed O 2 on TiO 2 surface to generate reactive species. In addition, all the doped samples have smaller crystallite sizes . The formation of B interstitials and Y substitutes, and increased surface-to-volume ratio are all beneficial to improve photocatalytic activity.
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AICHE JOURNAL
·
2025
·
IF 4
Ziqi Bian,Minhao Chen,Xiaohu Ge,Ningchao Zhu,Yueqiang Cao,Hao Jiang,Jing Zhang,Gang Qian,Xinggui Zhou,Xuezhi Duan
Designing and fabricating uniformly dispersed non-precious metal active sites with tuned geometric configurations and local coordination environments for the selective conversion of functional groups to desired products is of great importance but remains challenging in industrial catalytic processes. In this work, we propose a straightforward method for synthesizing the Co 3 Sn 2 intermetallic catalyst through the structural conversion of layered double hydroxide precursors, thereby constructing suitable Sn-modified Co active sites and an optimized catalytic environment for propyne semihydrogenation. Characterizations using x-ray diffraction, high-resolution transmission electron microscopy, and x-ray absorption spectroscopy characterizations are combined to identify the formation of P6 3 /mmc Co 3 Sn 2 intermetallic phase. Catalytic performance tests show that the Co 3 Sn 2 catalyst achieves 95.0% propylene selectivity with nearly complete propyne conversion. Temperature-programmed surface reaction and desorption measurements combined with theoretical calculations demonstrate that the good selectivity is driven by the facile desorption of propylene from Sn-modified Co sites rather than its further hydrogenation.
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Journal of Environmental Chemical Engineering
·
2024
·
IF 7.4
Zhaoyi Han,Hao Shi,Wentao Qiu,Dongdong Zhu,Wei Li,Dihua Wang
The excessive use of antibiotics like sulfamethoxazole (SMX) is causing environmental pollution and endangering human health and the ecosystem. Using transition metals as catalysts to activate persulfate (PS) can effectively degrade the organic pollutants in the advanced oxidation process (AOP). However, the high dissolution of the transition metals leads to poor stability, low efficiency in pollutant degradation, and secondary pollution. In this work, a graphitized carbon encapsulated Co (Co@EC) anode is developed for electrochemically activating peroxymonosulfate (PMS) to degrade SMX. It is found that the synergistic effect of Co@EC, PMS, and current significantly enhances SMX degradation. Under optimal conditions (current density of 5 mA cm −2 , pH of 9, and PMS concentration of 0.25 mM), the Co@EC anode can completely remove 10 μM of SMX in 9 min, a much higher efficiency compared to processes without PMS, Co, or current. The rapid reaction kinetics (6.69×10 −1 min −1 ) at optimal conditions are associated with the two main active species of 1 O 2 and O 2 • − during electroactivation. Furthermore, the Co@EC anode maintains high degradation efficiency and low dissolution after repeated cycling tests due to its structural stability. These findings provide new insights and strategies for developing stable catalysts.
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JOURNAL OF CATALYSIS
·
2024
·
IF 6.5
Yuxi Meng,Shaomian Liu,Yixi Wang,Wenqing Xu,Jiajian Gao,Sansan Yu,Fabing Su,Tingyu Zhu
Selective catalytic reduction of NO using CO (CO-SCR) is a promising technology for the purification of NO in the flue gas. However, the presence of O 2 significantly inhibits the activity of the CO-SCR catalyst. Herein, we synthesize a hollow Mn-doped CeO 2 @Co 3 O 4 catalyst (Mn-CeO 2 @Co 3 O 4 ), which achieved 82% NO conversion, 100% CO conversion, and 78% N 2 selectivity under 5 vol% O 2 at 200 °C, superior to those of CeO 2 @Co 3 O 4 and Co 3 O 4 @CeO 2 catalysts. The characterization results indicate that the strong electronic interaction at the heterointerfaces between Co 3 O 4 and CeO 2 plays a crucial role in promoting selective adsorption of NO. Furthermore, the Mn doping into the Co 3 O 4 lattice of the catalyst facilitates the conversion of N 2 O intermediates, thereby enhancing the overall activity. This research provides a new strategy for the design and synthesis of CO-SCR catalysts.
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