scholarly journals Ionothermally synthesized hierarchical porous Schiff-base-type polymeric networks with ultrahigh specific surface area for supercapacitors

RSC Advances ◽  
2017 ◽  
Vol 7 (32) ◽  
pp. 19934-19939 ◽  
Author(s):  
Yuhang Zhao ◽  
Ping Liu ◽  
Xiaodong Zhuang ◽  
Dongqing Wu ◽  
Fan Zhang ◽  
...  
Keyword(s):  
Schiff Base ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Synthesis Method ◽  
Ionothermal Synthesis ◽  
Polymeric Network ◽  
Polymeric Networks ◽  
Hierarchical Porous ◽  
One Step

A hierarchical porous polymeric network (HPPN) with ultrahigh specific surface area up to 2870 m2 g−1 was synthesized via a one-step ionothermal synthesis method without using templates.

scholarly journals Nanoporous Quasi-High-Entropy Alloy Microspheres

Metals ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 345 ◽  
Author(s):  
Lianzan Yang ◽  
Yongyan Li ◽  
Zhifeng Wang ◽  
Weimin Zhao ◽  
Chunling Qin
Keyword(s):  
Mechanical Properties ◽  
Solid Solution ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
High Specific Surface Area ◽  
High Entropy Alloy ◽  
Face Centered Cubic ◽  
High Entropy ◽  
Hierarchical Porous

High-entropy alloys (HEAs) present excellent mechanical properties. However, the exploitation of chemical properties of HEAs is far less than that of mechanical properties, which is mainly limited by the low specific surface area of HEAs synthesized by traditional methods. Thus, it is vital to develop new routes to fabricate HEAs with novel three-dimensional structures and a high specific surface area. Herein, we develop a facile approach to fabricate nanoporous noble metal quasi-HEA microspheres by melt-spinning and dealloying. The as-obtained nanoporous Cu30Au23Pt22Pd25 quasi-HEA microspheres present a hierarchical porous structure with a high specific surface area of 69.5 m2/g and a multiphase approximatively componential solid solution characteristic with a broad single-group face-centered cubic XRD pattern, which is different from the traditional single-phase or two-phase solid solution HEAs. To differentiate, these are named quasi-HEAs. The synthetic strategy proposed in this paper opens the door for the synthesis of porous quasi-HEAs related materials, and is expected to promote further applications of quasi-HEAs in various chemical fields.

Preparation of Fe/N co-doped hierarchical porous carbon nanosheets derived from chitosan nanofibers for high-performance supercapacitors

2021 ◽  
pp. 1-16
Author(s):  
Yaqi Yang ◽  
Ziqiang Shao ◽  
Feijun Wang
Keyword(s):  
Specific Surface ◽  
Specific Capacitance ◽  
Surface Area ◽  
Double Layer ◽  
Specific Surface Area ◽  
Porous Carbon ◽  
Active Sites ◽  
Transport Pathway ◽  
Carbon Nanosheets ◽  
Hierarchical Porous

Abstract Due to the low specific capacitance and small specific surface area of conventional carbon materials used as electrode materials for double-layer capacitors, the search for more ideal materials and ingenious preparation methods remains a major challenge. In this study, fractional porous carbon nanosheets were prepared by co-doping Fe and N with chitosan as nitrogen source. The advantage of this method is that the carbon nanosheets can have a large number of pore structures and produce a large specific surface area. The presence of Fe catalyzes the graphitization of carbon in the carbon layer during carbonization process, and further increases the specific surface area of the electrode material. This structure provides an efficient ion and electron transport pathway, which enables more active sites to participate in the REDOX reaction, thus significantly enhancing the electrochemical performance of SCs. The specific surface area of CS-800 is up to 1587 m2 g−1. When the current density is 0.5 A g−1, the specific capacitance of CS-800 reaches 308.84 F g−1, and remains 84.61 % of the initial value after 10,000 cycles. The Coulomb efficiency of CS-800 is almost 100 % after a long cycle, which indicates that CS-800 has more ideal double-layer capacitance and pseudo capacitance.

3D hierarchical porous amidoxime fibers speed up uranium extraction from seawater

2019 ◽  
Vol 12 (6) ◽  
pp. 1979-1988 ◽  
Author(s):  
Xiao Xu ◽  
Hongjun Zhang ◽  
Junxuan Ao ◽  
Lu Xu ◽  
Xiyan Liu ◽  
...  
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Nuclear Fuel ◽  
Specific Surface Area ◽  
New Technology ◽  
High Specific Surface Area ◽  
Fuel Production ◽  
Uranium Extraction ◽  
Hierarchical Porous ◽  
Speed Up

The development of high specific surface area amidoxime-based polymeric (H-ABP) fibers presents a new technology for the synthesis of highly efficient adsorbents for uranium extraction from seawater (UES), thus opening a whole new means of nuclear fuel production from the ocean.

scholarly journals Silkworm cocoon derived N, O-codoped hierarchical porous carbon with ultrahigh specific surface area for efficient capture of methylene blue with exceptionally high uptake: kinetics, isotherm, and thermodynamics

RSC Advances ◽  
2019 ◽  
Vol 9 (58) ◽  
pp. 33872-33882
Author(s):  
Genxing Zhu ◽  
Qi Liu ◽  
Fengyi Cao ◽  
Qi Qin ◽  
Mingli Jiao
Keyword(s):  
Methylene Blue ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Porous Carbon ◽  
Uptake Kinetics ◽  
High Uptake ◽  
Hierarchical Porous Carbon ◽  
Hierarchical Porous ◽  
Silkworm Cocoon

Silkworm cocoon derived N, O-HPC (SBET = 2270.19 m2 g−1) was synthesized, and demonstrated exceptionally high uptake of MB (2104.29 mg g−1).

scholarly journals The preparation of synthetic graphite materials with hierarchical pores from lignite by one-step impregnation and their characterization as dye absorbents

RSC Advances ◽  
2019 ◽  
Vol 9 (22) ◽  
pp. 12737-12746 ◽  
Author(s):  
Tian Qiu ◽  
Jian-Guo Yang ◽  
Xue-Jie Bai ◽  
Yu-Ling Wang
Keyword(s):  
Carbon Source ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Large Specific Surface Area ◽  
Hierarchical Pores ◽  
One Step ◽  
Synthetic Graphite

Herein, synthetic graphite materials with hierarchical pores and large specific surface area were prepared by one-step impregnation with lignite as the carbon source, H2SO4 as the oxidant, and H3PO4 as the activator.

Synthesis and Characterization of Porous Mo-W Oxide Nanostructures

2008 ◽  
Vol 8 (12) ◽  
pp. 6445-6450
Author(s):  
F. Paraguay-Delgado ◽  
Y. Verde ◽  
E. Cizniega ◽  
J. A. Lumbreras ◽  
G. Alonso-Nuñez
Keyword(s):  
Electron Microscopy ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Synthesis Method ◽  
Atomic Ratio ◽  
High Specific Surface Area ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Before And After

The present study reports the synthesis method, microstructure characterization, and thermal stability of nanostructured porous mixed oxide (MoO3-WO3) at 550 and 900 °C of annealing. The material was synthesized using a hydrothermal method. The precursor was prepared by aqueous solution using ammonium heptamolibdate and ammonium metatungstate, with an atomic ratio of Mo/W = 1. The pH was adjusted to 5, and then the solution was transferred to a teflon-lined stainless steel autoclave and heated at 200 °C for 48 h. The resultant material was washed using deionized water. The specific surface area, morphology, composition, and microstructure before and after annealing were studied by N2 physisorption, scanning electron microscopy (SEM), analytical transmission electron microscopy (TEM), and X-Ray diffraction (XRD). The initial synthesized materials showed low crystallinity and high specific surface area around (141 m2/g). After thermal annealing the material showed higher crystallinity and diminished its specific surface area drastically.

scholarly journals Three-Dimensional Hierarchical Porous Carbon Derived from Natural Resources for Highly Efficient Treatment of Polluted Water

2021 ◽  
Author(s):  
Jiaxin Li ◽  
Rudolf Holze ◽  
Simbarashe Moyo ◽  
Song Wang ◽  
Sanxi Li ◽  
...  
Keyword(s):  
Specific Surface ◽  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution ◽  
Surface Area ◽  
Specific Surface Area ◽  
Porous Carbon ◽  
Polluted Water ◽  
Hierarchical Porous Carbon ◽  
Hierarchical Porous

Abstract In this work, a series of three-dimensional (3D) porous carbon nanomaterial with large specific surface area and hierarchical pores were selectively prepared from biomass with varied properties obtained by tuning the carbonization temperature and activation agent. The optimized carbon sample (PC-500-6) exhibits a typical hierarchical porous structure with a high specific surface area (3203 m2/g) and pore size distribution in the range 0.8 to 3.0 nm, which shows excellent adsorption performance for methylene blue (MB) from an aqueous solution. The maximum adsorption capacity even reaches 917.43 mg/g, which is among one of the best results up to now. Through analysis of the adsorption data, it is found that the corresponding adsorption kinetic fits the pseudo-second-order model very well. The present results demonstrate that biomass-derived hierarchical porous carbon has a real potential application for wastewater treatment.Background:Dealing with the ever-increasing water pollution has become an urgent global problem, especially the organic containing polluted water. The physical adsorption has become one of the most popular ways for removal of organic dyes from wastewater due to its low cost as well as high efficiency. However, the adsorption performance is still limited by the low specific surface area (SSA) and unsuitable pore size. Hence, it is still a challenge to synthesize active carbon (AC) with high SSA, suitable pore size distribution as well as low cost for polluted water treatment. Here, we report an efficient method to prepare AC with large SSA from jujube for removal of MB in aqueous solution. The present results demonstrate that biomass-derived hierarchical porous carbon has a real potential application for wastewater treatment.Results:The as-prepared hierarchical porous structure carbon material (PC-500-6) shows a high specific surface area (3203 m2/g) and pore size distribution in the range 0.8 to 3.0 nm, while exhibits an enhanced adsorption performance for methylene blue (MB) from an aqueous solution. The maximum adsorption capacity even reaches 917.43 mg/g, which was calculated from Langmuir model. Through analysis of the adsorption data, it is found that the corresponding adsorption kinetic fits the pseudo-second-order model very well.Conclusions:It can be concluded that the adsorption of MB has a strong correlation with SSA, pore size distribution as well as the pore volume. The present study paved a practical way for wastewater treatment by using biomass-derived hierarchical porous carbon.

scholarly journals Towards the Continuous Hydrothermal Synthesis of ZnO@Mg2Al-CO3 Core-Shell Composite Nanomaterials

Nanomaterials ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 2052
Author(s):  
Ian Clark ◽  
Jacob Smith ◽  
Rachel L. Gomes ◽  
Edward Lester
Keyword(s):  
Composite Material ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Single Phase ◽  
Core Shell ◽  
Composite Nanomaterials ◽  
One Step ◽  
Double Hydroxide ◽  
Shell Composite

Core-shell Zinc Oxide/Layered Double Hydroxide (ZnO@LDH) composite nanomaterials have been produced by a one-step continuous hydrothermal synthesis process, in an attempt to further enhance the application potential of layered double hydroxide (LDH) nanomaterials. The synthesis involves two hydrothermal reactors in series with the first producing a ZnO core and the second producing the Mg2Al-CO3 shell. Crystal domain length of single phase ZnO and composite ZnO was 25 nm and 42 nm, respectively. The ZnO@LDH composite had a specific surface area of 76 m2 g−1, which was larger than ZnO or Mg2Al-CO3 when produced separately (53 m2 g−1 and 58 m2 g−1, respectively). The increased specific surface area is attributed to the structural arrangement of the Mg2Al-CO3 in the composite. Platelets are envisaged to nucleate on the core and grow outwards, thus reducing the face–face stacking that occurs in conventional Mg2Al-CO3 synthesis. The Mg/Al ratio in the single phase LDH was close to the theoretical ratio of 2, but the Mg/Al ratio in the composite was 1.27 due to the formation of Zn2Al-CO3 LDH from residual Zn2+ ions. NaOH concentration was also found to influence Mg/Al ratio, with lower NaOH resulting in a lower Mg/Al ratio. NaOH concentration also affected morphology and specific surface area, with reduced NaOH content in the second reaction stage causing a dramatic increase in specific surface area (> 250 m2 g−1). The formation of a core-shell composite material was achieved through continuous synthesis; however, the final product was not entirely ZnO@Mg2Al-CO3. The product contained a mixture of ZnO, Mg2Al-CO3, Zn2Al-CO3, and the composite material. Whilst further optimisation is required in order to remove other crystalline impurities from the synthesis, this research acts as a stepping stone towards the formation of composite materials via a one-step continuous synthesis.

Synthesis of Se/chitosan-derived hierarchical porous carbon composite as Li–Se battery cathode

2017 ◽  
Vol 10 (02) ◽  
pp. 1650074 ◽  
Author(s):  
Cheng Chen ◽  
Chenhao Zhao ◽  
Zhibiao Hu ◽  
Kaiyu Liu
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Discharge Capacity ◽  
Porous Carbon ◽  
Carbon Composite ◽  
High Rate ◽  
Electrochemical Performances ◽  
Hierarchical Porous Carbon ◽  
Hierarchical Porous

The hierarchical porous carbon with overall macropores and surface micropores has been prepared from carbonization of chitosan/[Formula: see text][Formula: see text] gel-like composite. The specific surface area and pore volume of this carbon can come to 2358.9[Formula: see text][Formula: see text] g[Formula: see text] and 1.14[Formula: see text]cm3 g[Formula: see text], respectively, and the active component Se with amorphous structure is uniformly encapsulated into the microporous structure to form Se/carbon composite. As Li–Se battery cathode, the composite delivers a second discharge capacity of 537.6[Formula: see text]mAh g[Formula: see text] at 0.2[Formula: see text]C, and a discharge capacity of 517.9[Formula: see text]mA h g[Formula: see text] can be retained after 100 cycles. Even at a high rate of 5[Formula: see text]C, the composite still reveals a stable discharge capacity of 325.2[Formula: see text]mAh g[Formula: see text]. The excellent electrochemical performances of Se/carbon composite may attribute to high specific surface area and hierarchical porous feature.

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