COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2022
·
IF 5.518
Shuai Wang,Junfeng Feng,Hui Pan
In this work, a nitrogen-doped lignin-derived hierarchical porous carbon material (LDMCN-700–2) was synthesized by a facile and green strategy using alkali lignin as carbon source, melamine as nitrogen source, and KCl as salt template. The as-prepared LDMCN-700–2 possessed unique structural properties such as a large surface area of 1012.5 m 2 ·g −1 , high nitrogen content of 4.5 at%, and hierarchical porous structure with micropores, mesopores and macropores, which endow it with superior electrochemical performance . The electrochemical measurements demonstrated that LDMCN-700 as an electrode material exhibited a high specific capacitance of 245 F·g −1 at 0.5 A·g −1 , as well as excellent cycling stability with 95.7 % capacitance retention after 5000th cyclic voltammetry cycles, indicating its great potential for supercapacitors .
研究领域:
材料科学
·
能源存储
✓ 已验证
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2019
·
IF 5.155
Jinlong Hu,Wenxin He,Shudi Qiu,Weijian Xu,Yaohua Mai,Fei Guo
Functionalized carbon electrodes with hierarchical porous structure play an essential role in the fabrication of high-performance supercapacitors . Here, we report a novel freeze-drying assisted carbonization approach for the preparation of nitrogen-doped hierarchically porous carbons (NHPCs). Using urea as both the pore-forming agent and the nitrogen source, and sodium alginate (SA) as the carbon precursor, we are able to modulate the porosity and N-doping concentration of the NHPCs by simply altering the carbonization temperature and the dosage of urea. The prepared NHPCs exhibit specific surface area as high as 1179 m 2 g −1 with 70% micropore and high N- and O-doping concentration of 6.7 wt% and 13.8 wt%, respectively. Carbon electrodes based on these NHPCs show a high gravimetric capacitance (305 F g −1 at 1 A g −1 ) and an excellent rate ability (retaining 73.8% at 20 A g −1 ) in three-electrode systems. The NHPCs symmetric supercapacitor delivers excellent energy density of up to 23.8 W h kg −1 as well as long-term electrochemical stability (95.8% capacitance retention over 10, 000 cycles). The abundance of the raw materials combined with the simple fabrication procedure makes the SA-derived NHPCs as promising electrode materials for the next generation advanced supercapacitors .
研究领域:
材料科学
·
能源存储技术
✓ 已验证
DOI
高影响因子
IONICS
·
2024
·Vol. 30
·期 3
·1373-1381
·
IF 2.4
Liu Xun,Xiong Kaiyang,Yuan Haoxiang,Zhao Junfeng
Herein, the well-designed hybrid materials composed of Fe 2 O 3 nanoparticles embedded in hierarchical porous carbon matrix (HPCs/Fe 2 O 3 ) were prepared by a two-step approach, involving a salt template route followed by hydrothermal treatment. The hierarchical porous structure not only serves as a buffer matrix to alleviate the volume expansion of Fe 2 O 3 nanoparticles, but also provides a large surface area and high electrical conductivity, resulting in significant improvement of electrochemical performance. HPCs/Fe 2 O 3 -2 anode delivers a high reversible capacity of 1357.60 mAh g −1 after 100 cycles at 0.2 A g −1 and an outstanding rate behavior. It also exhibits an excellent cycling-life stability of 472.3 mAh g −1 after 1000 cycles at a high current density of 5 A g −1 , suggesting its potential application in LIBs anode.
研究领域:
材料科学
·
电化学
·
储能
✓ 已验证
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2018
·
IF 8.097
Yunzhe Ding,Ying Yan,Hanwen Wang,Xinkui Wang,Tao Hu,Shengyang Tao,Guangtao Li
Diffusion is one of the most critical factors which affect the performance of porous catalysts in heterogeneous reactions. Hollow spheres with a hierarchical structure could significantly improve the mass transfer in the spherical catalyst. Therefore, preparation of such kind of microspheres is an important work in the field of inorganic synthesis. Herein, we combine microfluidic technology and electroless deposition to prepare hollow Cu and CuOx microspheres with a hierarchically porous structure. These microspheres have a controllable diameter (100–500 μm) and shell thickness (10–60 μm). Numerical simulation and experimental results indicate that the hollow structure is beneficial for the diffusion and utilization of the catalyst in heterogeneous reactions. The Cu and CuOx microspheres were used to catalyze the hydrogenation and Fenton-like reactions in a flow reactor, respectively. The conversion of all reactants can reach more than 95%, and catalysts can maintain their reactivity in long reaction times. Thus, the strategy in the present research should apply in the construction of other porous catalysts with high performance.
研究领域:
无机化学
·
材料科学
·
催化化学
✓ 已验证
DOI
高影响因子
Scientific Reports
·
2021
·Vol. 11
·期 1
·1-11
·
IF 4.38
Zhao Yanling,Zhang Xiaohua
In situ activation–graphitization method based on the atomically dispersed K and Fe in organic salts is developed to synthesize hierarchical porous graphitic carbon by directly pyrolysis potassium citrate and iron citrate. Moreover, (NH 4 ) 2 C 2 O 4 is also employed as both N dopant and porogen to open up internal structure and regulate pore structure. The inside-out activation leads to the homogeneous reaction and interconnected hierarchical porous structure with few dead pores. Accompanied by high specific surface area, appropriate pore distribution, good conductivity, and N/O functional groups, the sample exhibits high capacitance of 322.6 F g −1 at 0.5 A g −1 , good rate capability, and excellent cycling stability with 101.5% capacitance retention after 15,000 cycles. The supercapacitor shows an energy density of 21.3 W h kg −1 at 456.7 W kg −1 in 1 M Na 2 SO 4 . Easy synthesis, cost-effective, and environmentally benign, the work provides a promising strategy to produce hierarchical porous graphitic carbon applied in energy storage.
研究领域:
材料科学
·
能源存储
✓ 已验证
DOI
高影响因子
CRYSTENGCOMM
·
2017
·Vol. 19
·期 18
·2509-2516
·
IF 3.474
Dedong Jia,Zhen Qi,Xuequan Li,Linlin Li,Li-Hua Shao,Hong Liu
TiO2 is one of the most extensively investigated materials owing to its unique properties and several promising applications. The properties of TiO2 are highly dependent on its microstructure and feature size. Herein, we report a strategy for the synthesis of hierarchical porous TiO2 with two distinguishable scales of ligament sizes, which consists of both macro-pores and meso-pores. A metallic melt dealloying process with CuTi alloy was followed to form a porous Ti precursor. Subsequently, this precursor was used as a substrate for anodization to form TiO2. By controlling the anodization potential, time and initial porous Ti ligament size, nanotubular nanotubes or nanoporous TiO2 were distributed uniformly on the ligaments of porous Ti. Both the sizes of the macropore (400 nm to 2 μm) and mesopore (10 to 30 nm) can be tuned. A core–shell structured TiO2/Ti composite with a nanoporous or nanotubular structure in the shell and un-anodized porous Ti in the core can be achieved by partial anodization. The hierarchical structure with high surface area is essential for mass transport (large pore) and functionality (small pore), which makes it a potential candidate for various applications such as in sensors and catalysts.
研究领域:
材料科学
·
纳米技术
·
表面工程
·
化学合成
·
功能材料
✓ 已验证
DOI
高影响因子
Nanoscale
·
2020
·Vol. 12
·期 28
·15261-15274
·
IF 6.895
Qiuhong Bai,Yehua Shen,Taka-Aki Asoh,Cong Li,Yong Dan,Hiroshi Uyama
The controlled design and synthesis of porous carbons with anticipated microstructures and morphologies, and a high specific surface area (SSA) have been focused on for supercapacitor development. Here, hierarchical porous carbons (HPCs) with an interconnected three-dimensional morphology derived from a natural-based bacterial cellulose (BC) composite have been successfully prepared by thermally induced phase separation of poly(ethylene-co-vinyl alcohol) (EVOH) and subsequent carbonization/activation. The SSA and porous architectures can be controlled by fine-tuning the preparation conditions such as the precursor morphology and structure, activator dosage and activation temperature, and the relationships between the super-capacitive properties and the SSA and pore size distribution have been further investigated. The obtained porous carbon material possesses a hierarchical porous structure with moderate micropores, favorable mesopores, interconnected macropores, a high SSA of 2161 m2 g−1 and a maximum oxygen-dopant content of 9.99%, enabling an increase in the active materials utilization efficiency and wettability. Due to the synergistic effects of these features, the obtained porous carbon electrode used in a supercapacitor shows a high specific capacitance of 420 F g−1 at 0.5 A g−1, excellent rate performance with 75% capacitance retention at 20 A g−1, and good cycling stability with ∼96.1% retention even after 10 000 continuous charge–discharge cycles at 5 A g−1. Additionally, the assembled supercapacitor based on porous carbon displays a moderate energy density of 20 W h kg−1. The good electrochemical performance and facile effective synthesis of bio-derived carbon materials with tunable porous structures indicate promising applications in supercapacitors.
研究领域:
材料科学
·
能源存储
·
环境工程
✓ 已验证
DOI
高影响因子
MICROPOROUS AND MESOPOROUS MATERIALS
·
2020
·
IF 4.551
Yuanchao Shao,Hongjuan Wang,Xuefei Liu,Philip Ryan Haydel,Tianduo Li,Jianbin Chen,Peng Huang,Qiang Xiao,Takashi Tatsumi,Jingui Wang
Hierarchically porous zeolites are a type of very hot catalyst with improved catalytic performances as compared with conventional microporous-only zeolites due to the improved mass transportation among the hierarchical meso/macropores, which are expected to be the next-generation catalysts for conversion of bulky molecules and/or polymers. Moreover, hierarchical zeolites with the single crystalline structure that is an identical registry of micropores within the entire particle identified the less pore blockage and less diffusion limitation compared to an aggregated structure of nano-zeolites. The developed synthetic methods were mostly conducted in a liquid-phase system and usually required expensive additives, such as silanes or mesoporogons, etc. Finding facile and cost-effective synthetic methods have been still challenging. Here, a facile and cost-effective strategy by controlling the growth/crystallization in a solidified hydrogel system was reported for the synthesis of Ti-containing MFI-type zeolites (TS-1) to simultaneously achieve hierarchical porosity , single-crystalline structure, and high catalytic performance in alkene oxidations . The synthesized zeolites were characterized by XRD , SEM, TEM , Nitrogen adsorption analysis, DRUV spectroscopy, IR spectroscopy , etc. The growth processes were also tracked and well-characterized. It was found that the solid-phase transformation mechanism was dominated for forming the hierarchical structure. This strategy could directly produce TS-1 with abundant intracrystalline continuous mesopores and large amounts of active framework titanium species, contributing to higher activity for epoxidation of alkenes compared to the traditional microporous-only TS-1 zeolites.
研究领域:
催化
·
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
CARBOHYDRATE POLYMERS
·
2020
·
IF 7.182
Zhuan Fu,Sijie Zhou,Liangjun Xia,Yunshan Mao,Liyun Zhu,Yunqi Cheng,Aming Wang,Chunhua Zhang,Weilin Xu
Polycyclic aromatic hydrocarbons (PAHs) from cigarettes are one of the main pollutants affecting public health. Herein, a cellulose cigarette filter with three-dimensional (3D) hierarchically porous structure was fabricated using a natural cellulose Juncus effusus (JE) fiber, whose pore size was well controlled by biocompatible polyvinylpyrrolidone (PVP) using a simple dip-dry method. The adsorption capacity and mechanism of the PVP–JE filter tips (PJF) against PAHs were investigated in detail. Compared with conventional cellulose acetate filter tips (CAF), the cellulose PJF were superior at filtering and adsorbing of PAHs from mainstream smoke with the removal efficiency of 61.79 %, which was 22.57 % higher than that of CAF (39.22 %). The ternary structures including polymer filter membrane, 3D network, and interconnected channels were demonstrated as the main roles for highly effective removal of PAHs. The JE-based cellulose cigarette filter can be a promising candidature to broaden the application range of polysaccharide in pollutant elimination.
研究领域:
环境科学
·
公共卫生
·
材料科学
✓ 已验证
DOI
高影响因子
Journal of Energy Storage
·
2020
·
IF 3.762
Liming Xu,Jing Wu,Weiqiang Zhou,Fengxing Jiang,Jingkun Xu
A binder-free hierarchical porous N-doped graphene directly anchored on carbon fiber cloth was manufactured by a simple and practical two-step process, in which polyindole/graphene oxide (PIn/GO) composites were prepared by in-situ oxidation polymerization of indole on the surface of GO, and then PIn/GO composites coated on the surface of carbon fiber cloth was activated with KOH at 700 °C. By adjusting the contents of PIn, GO, and KOH, a hierarchical porous P7G-K-2 electrode with N content (4.98 at.%) was obtained and showed lager specific surface area and low interfacial contact resistance. The electrochemical evaluation showed that the P7G-K-2 electrode had a maximum specific capacitance of 451 F g − 1 at 1 A g − 1 and excellent rate performance. Moreover, a simple supercapacitor consisting of two symmetrical P7G-K-2 electrodes, P7G-K-2//P7G-K-2, was assembled, the specific energy of 21.8 Wh kg −1 can be obtained at the specific power of 75 W kg −1 , and it had excellent long-term cycle stability (maintaining 92% initial specific capacitance after 10,000 cycles). The excellent performance indicates that the P7G-K-2 is a promising candidate for supercapacitor electrode materials with high energy output. And this work provides a strategy to fabricate supercapacitors electrode with high specific power and specific energy.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
FUEL
·
2018
·
IF 4.908
Jiang-An You,Haiyan Song,Jin Zhang,Chunxia Chen,Fuqin Han
Novel hierarchical Al-KIL-2 aluminosilicates with bimodal mesoporous distribution were successfully synthesized via a feasible and cost-effective kinetic regulation method. The molar ratio of Si/Al, the kinetics of Al-Si polyanions growth and its following oriented-attachment on KIL-2 matrix were regulated aiming at various porous and acidic properties. The hierarchical Al-KIL-2 samples were characterized, and their adsorption capacities were tested by adsorptive denitrogenation for model fuels containing pyridine and quinoline. It was revealed that the branching epitaxial growth behavior originating from Al-zoning on KIL-2 matrix contributed to fabrication of the hierarchical porous structures. In addition, introduction of Al endowed KIL-2 with rich Lewis acid sites for the adsorption of basic contaminants. Hierarchical Al-KIL-2 obtained considerable adsorption efficiencies of pyridine and quinoline, the regularities of which relied on the appropriate kinetic regulation conditions during materials synthesis. The adsorption isotherms and adsorption thermodynamics research essentially presented the feature of this adsorptive denitrogenation system over hierarchical Al-KIL-2 for its potential industrial applications.
研究领域:
材料科学
·
环境工程
✓ 已验证
DOI
高影响因子
JOURNAL OF POWER SOURCES
·
2019
·
IF 7.467
Pengfei Tian,Jianbing Zang,Shiwei Song,Shuyu Zhou,Hongwei Gao,Hanqing Xu,Xueqing Tian,Yanhui Wang
A novel in situ templates etching method is used to prepare three-dimensional (3D) interconnected Fe-N doped hierarchical porous carbon materials. Citric acid serves as a carbon source and etchant. Fe 2 O 3 nanoparticles not only provide the iron source by in situ etching but also act as templates to construct the hierarchical porous structure. The prepared optimal sample displays a high specific surface area of 1643.6 m 2 g −1 with an interconnected abundant hierarchical porous structure and homogeneous distribution of Fe and N elements in the carbon. The optimized sample displays excellent catalytic oxygen reduction reaction (ORR) performance with a positive half-wave potential (0.85 V), efficient four-electron reaction and excellent durability, which are superior to those of Pt/C (20 wt%) catalyst. Meanwhile, due to the unique interconnected hierarchical porous structure, it also exhibits a high specific capacitance of 378.6 F g −1 at 0.5 A g −1 and an excellent rate capability of 276.6 F g −1 at 20 A g −1 as supercapacitors electrode materials in 6 M KOH. This work provides a simple design for the preparation of 3 D interconnected Fe-N doped hierarchical porous carbon electrode materials that display potential applications in ORR catalysts and supercapacitors.
研究领域:
材料科学
·
能源化学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）