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Weiran Wang Junpeng He Hongyu Guo Samuel G. Dunning Simon M. Humphrey Richard A. Jones 《Molecules (Basel, Switzerland)》2021,26(14)
A new terthiophene-based imidazole luminophore 5,5’-(1H-thieno[3,4-d]imidazole-4,6-diyl)bis(thiophene-2-carboxylic acid) (TIBTCH2, 5) was synthesized in one step from previously reported 4,6-di(thiophen-2-yl)-1H-thieno[3,4-d]imidazole (DTTI, 4), and their photophysical properties were studied and compared accordingly. Under solvothermal conditions, reacting 5 with Mn(OAc)2 yielded a new three-dimensional metal-organic framework (MOF, 6) which was structurally defined by single-crystal X-ray diffraction. In 6, all Mn(II) ions octahedrally bind to carboxylate-O atoms to form a linear Mn3 secondary building unit (SBU) that contains three distinct coordination modes. Importantly, 6 exhibits dual functional properties of ligand-based emission and metal-based magnetic behaviors. 相似文献
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Kai Chen Jia‐Long Ling Chuan‐De Wu 《Angewandte Chemie (International ed. in English)》2020,59(5):1925-1931
Heterostructural metal/metal oxides are the very promising substituents of noble‐metal catalysts; however, generation and further stabilization of accessible metal/metal oxide heterojunctions are very difficult. A strategy to encapsulate and stabilize Cu/Cu2O nanojunctions in porous organic frameworks in situ is developed by tuning the acrylate contents in copper‐based metal–organic frameworks (Cu‐MOFs) and the pyrolytic conditions. The acrylate groups play important roles on improving the polymerization degree of organic frameworks and generating and stabilizing highly dispersed and accessible Cu/Cu2O heteronanojunctions. As a result, pyrolysis of the MOF ZJU‐199, consisting of three acrylates per ligand, generates abundant heterostructural Cu/Cu2O discrete domains inside porous organic matrices at 350 °C, demonstrating excellent catalytic properties in liquid‐phase hydrogenation of furfural into furfuryl alcohol, which are much superior to the non‐noble metal‐based catalysts. 相似文献
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Gang Huang Li Yang Xiao Ma Prof. Dr. Jun Jiang Prof. Dr. Shu‐Hong Yu Prof. Dr. Hai‐Long Jiang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(10):3470-3477
Metal‐free catalysts are of great importance and alternative candidates to conventional metal‐based catalysts for many reactions. Herein, several types of metal–organic frameworks have been exploited as templates/precursors to afford porous carbon materials with various nitrogen dopant forms and contents, degrees of graphitization, porosities, and surface areas. Amongst these materials, the PCN‐224‐templated porous carbon material optimized by pyrolysis at 700 °C (denoted as PCN‐224‐700) is composed of amorphous carbon coated with well‐defined graphene layers, offering a high surface area, hierarchical pores, and high nitrogen content (mainly, pyrrolic nitrogen species). Remarkably, as a metal‐free catalyst, PCN‐224‐700 exhibits a low activation energy and superior activity to most metallic catalysts in the catalytic reduction of 4‐nitrophenol to 4‐aminophenol. Theoretical investigations suggest that the content and type of the nitrogen dopant play crucial roles in determining the catalytic performance and that the pyrrolic nitrogen species makes the dominant contribution to this activity, which explains the excellent efficiency of the PCN‐224‐700 catalyst well. 相似文献
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Xiang‐Lan Chen Jia‐Wei Huang Yi‐Chen Huang Jie Du Yu‐Fei Jiang Yue Zhao Hai‐Bin Zhu 《化学:亚洲杂志》2019,14(7):995-1003
Fe‐Co‐N‐C electrocatalysts have proven superior to their counterparts (e.g. Fe‐N‐C or Co‐N‐C) for the oxygen reduction reaction (ORR). Herein, we report on a unique strategy to prepare Fe‐Co‐N‐C?x (x refers to the pyrolysis temperature) electrocatalysts which involves anion‐exchange of [Fe(CN)6]3? into a cationic CoII‐based metal‐organic framework precursor prior to heat treatment. Fe‐Co‐N‐C‐900 exhibits an optimal ORR catalytic performance in an alkaline electrolyte with an onset potential (Eonset: 0.97 V) and half‐wave potential (E1/2: 0.86 V) comparable to that of commercial Pt/C (Eonset=1.02 V; E1/2=0.88 V), which outperforms the corresponding Co‐N‐C‐900 sample (Eonset=0.92 V; E1/2=0.84 V) derived from the same MOF precursor without anion‐exchange modification. This is the first example of Fe‐Co‐N‐C electrocatalysts fabricated from a cationic CoII‐based MOF precursor that dopes the Fe element via anion‐exchange, and our current work provides a new entrance towards MOF‐derived transition‐metal (e.g. Fe or Co) and nitrogen‐codoped carbon electrocatalysts with excellent ORR activity. 相似文献
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《化学:亚洲杂志》2017,12(24):3110-3113
We developed a metalloligand strategy to construct porous frameworks, viz. the combined use of IrIII‐based octahedral metalloligands and the linear unit [Ni(cyclam)] easily afforded two isostructural complexes 1 and 2 with primitive cubic frameworks. Both complexes show good CO2/N2 separation property. 相似文献
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《化学:亚洲杂志》2017,12(14):1816-1823
Heteroatom‐doped carbon materials have been considered as potential substitutes for Pt‐based electrocatalysts for the oxygen reduction reaction (ORR) in alkaline fuel cells. Here we report the synthesis of oxygen‐containing nitrogen‐doped carbon (ONC) nanosheets through the carbonization of a mixture that contained glucose and dicyandiamide (DCDA). In situ formed graphitic carbon nitride (g‐C3N4) derived from DCDA provided a nitrogen‐rich template, thereby facilitating the formation of ONC nanosheets. The resultant ONC materials with high nitrogen content, high specific surface areas, and highly mesoporous total volume displayed excellent electrochemical performance, including a similar ORR onset potential, half‐potential, a higher diffusion‐limited current, and excellent tolerance to methanol than that of the commercial Pt/C catalyst, respectively. Moreover, the ONC‐850 nanosheet displayed high long‐term durability even after 1000 cycles as well as a high electron transfer number of 3.92 (4.0 for Pt/C). Additionally, this work provides deeper insight into these materials and a versatile strategy for the synthesis of cost‐effective 2D N‐doped carbon electrocatalysts. 相似文献
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Xuan Wei Diao Zheng Ming Zhao Hongzhong Chen Xun Fan Bin Gao Long Gu Yi Guo Jianbin Qin Jing Wei Yanli Zhao Guangcheng Zhang 《Angewandte Chemie (International ed. in English)》2020,59(34):14639-14646
Heteroatom‐doped polymers or carbon nanospheres have attracted broad research interest. However, rational synthesis of these nanospheres with controllable properties is still a great challenge. Herein, we develop a template‐free approach to construct cross‐linked polyphosphazene nanospheres with tunable hollow structures. As comonomers, hexachlorocyclotriphosphazene provides N and P atoms, tannic acid can coordinate with metal ions, and the replaceable third comonomer can endow the materials with various properties. After carbonization, N/P‐doped mesoporous carbon nanospheres were obtained with small particle size (≈50 nm) and high surface area (411.60 m2 g?1). Structural characterization confirmed uniform dispersion of the single atom transition metal sites (i.e., Co‐N2P2) with N and P dual coordination. Electrochemical measurements and theoretical simulations revealed the oxygen reduction reaction performance. This work provides a solution for fabricating diverse heteroatom‐containing polymer nanospheres and their derived single metal atom doped carbon catalysts. 相似文献
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Dr. Xingwang Lan Yiming Li Cheng Du Tiantian She Qing Li Prof. Guoyi Bai 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(36):8560-8569
Porous carbon nitride frameworks (PCNFs) with uniform and rich nitrogen dopants and abundant porosity were successfully fabricated through the direct carbonization of the covalent triazine frameworks (CTFs) at different pyrolysis temperatures and used as supports to anchor and stabilize Ag nanoparticles (NPs) for catalytic CO2 conversion. Importantly, the pyrolysis temperature plays a crucial role in the properties of porous carbon nitride frameworks. The material carbonized at 700 °C showed the highest surface area and micro- and mesoporous structure with a certain interlayer distance. Taking advantage of their unique surface characteristics, PCNF-supported Ag NP catalysts (Ag/PCNF-T, T=pyrolysis temperature) were prepared by a simple chemical method. A series of characterizations revealed that Ag NPs are embedded in the porous carbon nitride frameworks and confined to a relatively small size with high dispersion owing to the assistance of the abundant surface groups and porous structures. The as-obtained Ag/PCNF-T catalysts, especially Ag/PCNF-700, showed excellent catalytic activity, selectivity, and stability for the carboxylation of CO2 with terminal alkynes under mild conditions. This can be due to the existence of abundant nitrogen atoms and diverse porosity, which resulted in highly efficient catalytic activity and stability. 相似文献
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Rational Design of MOF/COF Hybrid Materials for Photocatalytic H2 Evolution in the Presence of Sacrificial Electron Donors 下载免费PDF全文
Dr. Feng‐Ming Zhang Jing‐Li Sheng Prof. Zhao‐Di Yang Prof. Xiao‐Jun Sun Hong‐Liang Tang Meng Lu Hong Dong Feng‐Cui Shen Dr. Jiang Liu Prof. Ya‐Qian Lan 《Angewandte Chemie (International ed. in English)》2018,57(37):12106-12110
Crystalline and porous covalent organic frameworks (COFs) and metal‐organic frameworks (MOFs) materials have attracted enormous attention in the field of photocatalytic H2 evolution due to their long‐range order structures, large surface areas, outstanding visible light absorbance, and tunable band gaps. In this work, we successfully integrated two‐dimensional (2D) COF with stable MOF. By covalently anchoring NH2‐UiO‐66 onto the surface of TpPa‐1‐COF, a new type of MOF/COF hybrid materials with high surface area, porous framework, and high crystallinity was synthesized. The resulting hierarchical porous hybrid materials show efficient photocatalytic H2 evolution under visible light irradiation. Especially, NH2‐UiO‐66/TpPa‐1‐COF (4:6) exhibits the maximum photocatalytic H2 evolution rate of 23.41 mmol g?1 h?1 (with the TOF of 402.36 h?1), which is approximately 20 times higher than that of the parent TpPa‐1‐COF and the best performance photocatalyst for H2 evolution among various MOF‐ and COF‐based photocatalysts. 相似文献
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Metal–organic frameworks (MOFs) are promising alternative precursors for the fabrication of heteroatom‐doped carbon materials for energy storage and conversion. However, the direct pyrolysis of bulk MOFs usually gives microporous carbonaceous materials, which significantly hinder the mass transportation and the accessibility of active sites. Herein, N‐doped carbon aerogels with hierarchical micro‐, meso‐, and macropores were fabricated through one‐step pyrolysis of zeolitic imidazolate framework‐8/carboxymethylcellulose composite gel. Owing to the hierarchical porosity, high specific surface area, favorable conductivity, excellent thermal and chemical stability, the as‐prepared N‐doped carbon aerogel exhibits excellent oxygen reduction reaction (ORR) activity, long‐term durability, and good methanol tolerance in alkaline medium. This work thus provides a new way to fabricate new types of MOF‐derived carbon aerogels for various applications. 相似文献
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Xuan Wei Diao Zheng Ming Zhao Dr. Hongzhong Chen Xun Fan Bin Gao Dr. Long Gu Dr. Yi Guo Dr. Jianbin Qin Prof. Jing Wei Prof. Yanli Zhao Prof. Guangcheng Zhang 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(34):14747-14754
Heteroatom-doped polymers or carbon nanospheres have attracted broad research interest. However, rational synthesis of these nanospheres with controllable properties is still a great challenge. Herein, we develop a template-free approach to construct cross-linked polyphosphazene nanospheres with tunable hollow structures. As comonomers, hexachlorocyclotriphosphazene provides N and P atoms, tannic acid can coordinate with metal ions, and the replaceable third comonomer can endow the materials with various properties. After carbonization, N/P-doped mesoporous carbon nanospheres were obtained with small particle size (≈50 nm) and high surface area (411.60 m2 g−1). Structural characterization confirmed uniform dispersion of the single atom transition metal sites (i.e., Co-N2P2) with N and P dual coordination. Electrochemical measurements and theoretical simulations revealed the oxygen reduction reaction performance. This work provides a solution for fabricating diverse heteroatom-containing polymer nanospheres and their derived single metal atom doped carbon catalysts. 相似文献
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Selective catalytic reduction (SCR) of NOx with H2 as a reductant is the most promising denitration technology at low temperature. Achieving the conversion of NOx into N2 at ambient temperature not only prolongs the service life of the catalyst, but also provides more freedom for the arrangement of denitration units throughout the flue gas treatment equipment. However, the development of highly efficient, stable, and environmentally benign supported platinum‐based catalysts for H2‐SCR at ambient temperature is still a major challenge. Herein, a 0.5 wt % Pt/ZrO2@C catalyst, which was composed of carbon‐coated octahedral ZrO2 with highly dispersed Pt particles, was prepared by using a new stabilization strategy based on UiO‐66‐NH2 (a zirconium metal–organic framework) as a template. The catalytic performance of this Pt/ZrO2@C in H2‐SCR was tested and confirmed to achieve near 100 % NOx conversion at 90 °C. Also, 70 % N2 selectivity of the catalyst was achieved. The morphology, structure, and porous properties of the as‐synthesized nanocomposites were characterized by using data obtained from field‐emission SEM, TEM, XRD, Raman spectroscopy, thermogravimetric analysis, X‐ray photoelectron spectroscopy, and N2 adsorption–desorption isotherms. The results show that residual carbon formed by pyrolysis treatment is coated on octahedral ZrO2, and effectively prevents the agglomeration of platinum particles on the surface. 相似文献
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通过XRD,BET,In-situ XPS等表征技术对Cu/ZnO基甲醇裂解制氢催化剂进行 了详细的研究。XRD结果表明,Cu-Zn合金的生成是Cu/ZnO基催化剂在反应初期快速 失活的主要原因;XRD,BET和N_2O滴定实验结果表明,Ni助剂可能是通过提高 Cu~0活性物种的分散度并维持Cu~0活性物种在催化反应过程中的稳定性而使 Cu/Zn/Ni催化剂的活性及稳定性大幅度提高。In-situ XPS结果表明,Ni助剂的加 入可以诱导Cu/Zn/Ni催化剂表面在甲醇裂解反应过程中出现Cu~+,从而由 Cu~0/Cu~+共同构成催化剂的活性中心,并最终导致Cu/Zn/Ni催化剂的高活性。 相似文献
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Jing Yang Jiamin Zou Wei Zhong Jin Zou Yansha Gao Shuwu Liu Songbai Zhang Limin Lu 《Molecules (Basel, Switzerland)》2022,27(20)
A facile and sensitive electrochemical aptamer sensor (aptasensor) based on Au nanoparticles-decorated porous carbon (AuNPs/PC) composite was developed for the efficient determination of the antibiotic drug chloramphenicol (CAP). AuNPs modified metal-organic framework (AuNPs/ZIF-8) is applied as a precursor to synthesize the porous carbon with homogeneous AuNPs distribution through a direct carbonization step under nitrogen atmosphere. The as-synthesized AuNPs/PC exhibits high surface area and improved conductivity. Moreover, the loading AuNPs could enhance the attachment of the aptamers on the surface of electrode through the Au–S bond. When added to CAP, poorly conductive aptamer-CAP complexes are formed on the sensor surface, which increases the hindrance to electron transfer resulting in a decrease in electrochemical signal. Based on this mechanism, the developed CAP aptasensor represents a wide linear detection range of 0.1 pM to 100 nM with a low detection limit of 0.03 pM (S/N = 3). In addition, the proposed aptasensor was employed for the analysis of CAP in honey samples and provided satisfactory recovery. 相似文献
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Haichao Yang Ao Xie Dr. Yang Tang Zixiang Wang Jinpeng Zhang Dr. Lingpo Kong Dr. Peng Song Dr. Yanzhi Sun Dr. Xiaojin Yang Prof. Pingyu Wan 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(2):e202103275
It is a great challenge to fabricate highly efficient pH-universal electrocatalysts for oxygen reduction reaction (ORR). Herein, a facile strategy, which includes coating the Fe modified ZIF8 on Cu foil and in situ pyrolysis to evaporate and dope Cu into the MOF derived carbon, is developed to fabricate Fe/Cu−N co-doped carbon material (Cu/Fe−NC). Profiting from the modulated electron distribution and textual properties, well-designed Cu/Fe−NC exhibits superior half-wave potential (E1/2) of 0.923 V in alkaline, 0.757 V in neutral and comparable 0.801 V in acid electrolytes, respectively. Furthermore, the ultralow peroxides yield of ORR demonstrates the high selectivity of Cu/Fe−NC in full pH scale electrolytes. As expected, the self-made alkaline and neutral zinc-air batteries equipped with Cu/Fe−NC cathode display excellent discharge voltages, outstanding peak power densities and remarkable stability. This work opens a new way to fabricate highly efficient and pH-universal electrocatalysts for ORR through strategy of Fe/Cu−N co-doping, Cu foil evaporation and carbon defects capture. 相似文献
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Pomelo peel waste-derived porous carbon (PPPC) was prepared by a facile one-step ZnCl2 activation method. The preparation parameters of PPPC were the mass ratio of ZnCl2 to pomelo peel of 2:1, carbonization temperature of 500 °C, and carbonization time of 1 h. This obtained PPPC possessed abundant macro-,meso-, and micro-porous structures, and a large specific surface area of 939.4 m2 g−1. Surprisingly, it had excellent adsorption ability for methylene blue, including a high adsorption capacity of 602.4 mg g−1 and good reusability. The adsorption isotherm and kinetic fitted with Langmuir and pseudo-second order kinetic models. This work provides a novel strategy for pomelo peel waste utilization and a potential adsorbent for treating dye wastewater. 相似文献
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Xiaoxia Lv Xue Xue Xingyu Gan Chenhao Lv Xiaochen Sun Yun Wang Liangjun Li Hua Wang 《化学:亚洲杂志》2020,15(3):432-439
High‐performance non‐noble electrocatalysts for oxygen reduction reaction (ORR) are the prerequisite for large‐scale utilization of fuel cells. Herein, a type of sandwiched‐like non‐noble electrocatalyst with highly dispersed FeNx active sites embedded in a hierarchically porous carbon/graphene heterostructure was fabricated using a bottom‐up strategy. The in situ ion substitution of Fe3+ in a nitrogen‐containing MOF (ZIF‐8) allows the Fe‐heteroatoms to be uniformly distributed in the MOF precursor, and the assembly of Fe‐doped ZIF‐8 nano‐crystals with graphene‐oxide and in situ reduction of graphene‐oxide afford a sandwiched‐like Fe‐doped ZIF‐8/graphene heterostructure. This type of heterostructure enables simultaneous optimization of FeNx active sites, architecture and interface properties for obtaining an electron‐catalyst after a one‐step carbonization. The synergistic effect of these factors render the resulting catalysts with excellent ORR activities. The half‐wave potential of 0.88 V vs. RHE outperforms most of the none‐noble metal catalyst and is comparable with the commercial Pt/C (20 wt %) catalyst. Apart from the high activity, this catalyst exhibits excellent durability and good methanol‐tolerance. Detailed investigations demonstrate that a moderate content of Fe dopants can effectively increase the intrinsic activities, and the hybridization of graphene can enhance the reaction kinetics of ORR. The strategy proposed in this work gives an inspiration towards developing efficient noble‐metal‐free electrocatalysts for ORR. 相似文献
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Lin Ye Yiran Ying Dengrong Sun Zhouyang Zhang Linfeng Fei Zhenhai Wen Jinli Qiao Haitao Huang 《Angewandte Chemie (International ed. in English)》2020,59(8):3244-3251
We report a straightforward strategy to design efficient N doped porous carbon (NPC) electrocatalyst that has a high concentration of easily accessible active sites for the CO2 reduction reaction (CO2RR). The NPC with large amounts of active N (pyridinic and graphitic N) and highly porous structure is prepared by using an oxygen‐rich metal–organic framework (Zn‐MOF‐74) precursor. The amount of active N species can be tuned by optimizing the calcination temperature and time. Owing to the large pore sizes, the active sites are well exposed to electrolyte for CO2RR. The NPC exhibits superior CO2RR activity with a small onset potential of ?0.35 V and a high faradaic efficiency (FE) of 98.4 % towards CO at ?0.55 V vs. RHE, one of the highest values among NPC‐based CO2RR electrocatalysts. This work advances an effective and facile way towards highly active and cost‐effective alternatives to noble‐metal CO2RR electrocatalysts for practical applications. 相似文献