scholarly journals Nanoporous Carbon Materials Derived from Washnut Seed with Enhanced Supercapacitance

Materials ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2371 ◽  
Author(s):  
Ram Lal Shrestha ◽  
Timila Shrestha ◽  
Birendra Man Tamrakar ◽  
Rekha Goswami Shrestha ◽  
Subrata Maji ◽  
...  
Keyword(s):  
Surface Area ◽  
Electrode Materials ◽  
Carbon Materials ◽  
Activated Carbons ◽  
Low Cost ◽  
Rate Capability ◽  
Nanoporous Carbon ◽  
High Rate ◽  
Supercapacitor Electrode ◽  
Nanoporous Carbon Materials

Nanoporous activated carbons-derived from agro-waste have been useful as suitable and scalable low-cost electrode materials in supercapacitors applications because of their better surface area and porosity compared to the commercial activated carbons. In this paper, the production of nanoporous carbons by zinc chloride activation of Washnut seed at different temperatures (400–1000 °C) and their electrochemical supercapacitance performances in aqueous electrolyte (1 M H2SO4) are reported. The prepared nanoporous carbon materials exhibit hierarchical micro- and meso-pore architectures. The surface area and porosity increase with the carbonization temperature and achieved the highest values at 800 °C. The surface area was found in the range of 922–1309 m2 g−1. Similarly, pore volume was found in the range of 0.577–0.789 cm3 g−1. The optimal sample obtained at 800 °C showed excellent electrochemical energy storage supercapacitance performance. Specific capacitance of the electrode was calculated 225.1 F g−1 at a low current density of 1 A g−1. An observed 69.6% capacitance retention at 20 A g−1 indicates a high-rate capability of the electrode materials. The cycling stability test up to 10,000 cycles revealed the outstanding stability of 98%. The fascinating surface textural properties with outstanding electrochemical performance reveal that Washnut seed would be a feasible agro-waste precursor to prepare nanoporous carbon materials as a low-cost and scalable supercapacitor electrode.

scholarly journals High Surface Area Nanoporous Graphitic Carbon Materials Derived from Lapsi Seed with Enhanced Supercapacitance

Nanomaterials ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 728 ◽  
Author(s):  
Lok Kumar Shrestha ◽  
Rekha Goswami Shrestha ◽  
Subrata Maji ◽  
Bhadra P. Pokharel ◽  
Rinita Rajbhandari ◽  
...  
Keyword(s):  
Surface Area ◽  
Current Density ◽  
Electrode Materials ◽  
Carbon Materials ◽  
High Surface ◽  
High Surface Area ◽  
Graphitic Carbon ◽  
High Rate ◽  
Surface Areas ◽  
Nanoporous Carbon Materials

Nanoporous activated carbon materials derived from agro-wastes could be suitable low-cost electrode materials for high-rate performance electrochemical supercapacitors. Here we report high surface area nanoporous carbon materials derived from Lapsi seed agro-waste prepared by zinc chloride (ZnCl2) activation at 700 °C. Powder X-ray diffraction (pXRD) and Raman scattering confirmed the amorphous structure of the resulting carboniferous materials, which also incorporate oxygen-containing functional groups as confirmed by Fourier transform infrared (FTIR) spectroscopy. Scanning and transmission electron microscopy (SEM and TEM) analyses revealed the granular, nanoporous structures of the materials. High-resolution TEM (HR-TEM) confirmed a graphitic carbon structure containing interconnected mesopores. Surface areas and pore volumes of the materials were found, respectively, in the ranges from 931 to 2272 m2 g−1 and 0.998 to 2.845 cm3 g−1, and are thus superior to commercially available activated carbons. High surface areas, large pore volumes and interconnected mesopore structures of these Lapsi seed-derived nanoporous carbon materials lead to their excellent electrochemical supercapacitance performance in aqueous electrolyte (1 M H2SO4) with a maximum specific capacitance of 284 F g−1 at a current density of 1 A g−1. Furthermore, the electrodes showed high-rate capability sustaining 67.7% capacity retention even at high current density of 20 A g−1 with excellent cycle stability achieving 99% capacitance retention even after 10,000 charge–discharge cycles demonstrating the potential of Lapsi seed derived nanoporous carbons as suitable electrode materials in high-performance supercapacitor devices.

scholarly journals Synthesis of Hierarchical Graphene-MnO2 Nanowire Composites with Enhanced Specific Capacitance

2019 ◽  
Vol 31 (8) ◽  
pp. 1709-1718
Author(s):  
T. Veldevi ◽  
K. Thileep Kumar ◽  
R.A. Kalaivani ◽  
S. Raghu ◽  
A.M. Shanmugharaj
Keyword(s):  
Surface Area ◽  
Electrode Materials ◽  
High Surface ◽  
Specific Capacity ◽  
High Surface Area ◽  
Rate Capability ◽  
Sulfate Solution ◽  
High Rate ◽  
Chemical Compositions ◽  
Structure Morphology

Hierarchical nanostructured graphene–manganese dioxide nanowire (G-MnO2-NW) composites have been prepared by hydrothermal synthesis route using water/1-decanol as the medium. Synthesized materials were analyzed using various characterization tools to corroborate their chemical compositions, structure/morphology and surface area. Electrochemical measurements of the synthesized G-MnO2-NW electrode materials delivered the highest specific capacity (255 Fg-1), high rate capability and improved cycling stability at 0.5 Ag–1 in 1M sodium sulfate solution and this fact may be attributed to its high surface area and porosity. Moreover, synthesized G-MnO2-NW electrodes displayed better energy and power density, when compared to the MnO2-NW based electrodes.

scholarly journals Nanoarchitectonics of Lotus Seed Derived Nanoporous Carbon Materials for Supercapacitor Applications

Materials ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 5434
Author(s):  
Ram Lal Shrestha ◽  
Rashma Chaudhary ◽  
Timila Shrestha ◽  
Birendra Man Tamrakar ◽  
Rekha Goswami Shrestha ◽  
...  
Keyword(s):  
Energy Storage ◽  
Carbon Materials ◽  
Agricultural Waste ◽  
Rate Capability ◽  
High Energy ◽  
Nanoporous Carbon ◽  
High Energy Density ◽  
Lotus Seed ◽  
Nanoporous Carbon Materials ◽  
Supercapacitor Applications

Of the available environmentally friendly energy storage devices, supercapacitors are the most promising because of their high energy density, ultra-fast charging-discharging rate, outstanding cycle life, cost-effectiveness, and safety. In this work, nanoporous carbon materials were prepared by applying zinc chloride activation of lotus seed powder from 600 °C to 1000 °C and the electrochemical energy storage (supercapacitance) of the resulting materials in aqueous electrolyte (1M H2SO4) are reported. Lotus seed-derived activated carbon materials display hierarchically porous structures comprised of micropore and mesopore architectures, and exhibited excellent supercapacitance performances. The specific surface areas and pore volumes were found in the ranges 1103.0–1316.7 m2 g−1 and 0.741–0.887 cm3 g−1, respectively. The specific capacitance of the optimum sample was ca. 317.5 F g−1 at 5 mV s−1 and 272.9 F g−1 at 1 A g−1 accompanied by high capacitance retention of 70.49% at a high potential sweep rate of 500 mV s−1. The electrode also showed good rate capability of 52.1% upon increasing current density from 1 to 50 A g−1 with exceptional cyclic stability of 99.2% after 10,000 cycles demonstrating the excellent prospects for agricultural waste stuffs, such as lotus seed, in the production of the high performance porous carbon materials required for supercapacitor applications.

scholarly journals Jackfruit Seed-Derived Nanoporous Carbons as the Electrode Material for Supercapacitors

2020 ◽  
Vol 6 (4) ◽  
pp. 73 ◽  
Author(s):  
Rashma Chaudhary ◽  
Subrata Maji ◽  
Rekha Goswami Shrestha ◽  
Ram Lal Shrestha ◽  
Timila Shrestha ◽  
...  
Keyword(s):  
Carbon Materials ◽  
Activated Carbons ◽  
High Current Density ◽  
Chemical Activation ◽  
High Surface ◽  
High Surface Area ◽  
Rate Capability ◽  
High Specific Capacitance ◽  
High Rate ◽  
Nanoporous Carbons

Hierarchically porous activated carbon materials from agro-waste, Jackfruit seeds are prepared by a chemical activation method involving the treatment with zinc chloride (ZnCl2) at different temperatures (600–1000 °C). The electrochemical supercapacitance performances of the prepared materials were studied in an aqueous electrolyte (1 M sulfuric acid, H2SO4) in a three-electrode system. Jackfruit seed carbons display nanoporous structures consisting of both micro- and mesopore architectures and they are amorphous in nature and also contain oxygenated surface functional groups, as confirmed by powder X-ray diffraction (pXRD), Raman scattering, and Fourier-transformed infrared (FTIR) spectroscopy, respectively. The surface areas and pore volumes were found to be 1216.0 to 1340.4 m2·g−1 and 0.804 to 1.144 cm3·g−1, respectively, demonstrating the better surface textural properties compared to the commercial activated carbons. Due to the high surface area, large pore volume, and well developed hierarchical micro- and mesoporosity, the optimal sample achieved a high specific capacitance of 292.2 F·g−1 at 5 mV·s−1 and 261.3 F·g−1 at 1 A·g−1 followed by outstanding high rate capability. The electrode sustained 71.6% capacity retention at a high current density of 20 A·g−1. Furthermore, the electrode displayed exceptional cycling stability with small capacitance loss (0.6%) even after 10,000 charging–discharging cycles, suggesting that Jackfruit seed would have potential in low-cost and scalable production of nanoporous carbon materials for supercapacitors applications.

scholarly journals Achieving of High Density/Utilization of Active Groups via Synergic Integration of C=N and C=O Bonds for Ultra-Stable and High-Rate Lithium-Ion Batteries

Research ◽  
2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Tao Sun ◽  
Zong-Jun Li ◽  
Xin-Bo Zhang
Keyword(s):  
Electrode Materials ◽  
High Current Density ◽  
Low Cost ◽  
Rate Capability ◽  
Lithium Ion ◽  
High Rate ◽  
Electrochemical Performances ◽  
Environmental Friendliness ◽  
Practical Applications ◽  
Organic Electrode

Organic electrode materials are receiving ever-increasing research interest due to their combined advantages, including resource renewability, low cost, and environmental friendliness. However, their practical applications are still terribly plagued by low conductivity, poor rate capability, solubility in electrolyte, and low density/utilization of active groups. In response, herein, as a proof-of-concept experiment, C=N and C=O bonds are synergically integrated into the backbone of pentacene to finely tune the electronic structures of pentacene. Unexpectedly, the firstly obtained unique 5,7,11,14-tetraaza-6,13-pentacenequinone/reduced graphene oxide (TAPQ/RGO) composite exhibits superior electrochemical performances, including an ultra-stable cycling stability (up to 2400 cycles) and good rate capability (174 mAh g−1 even at a high current density of 3.2 A g−1), which might be attributed to the abundant active groups, π-conjugated molecular structure, leaf-like morphology, and the interaction between TAPQ and graphene.

scholarly journals Rice Husk-Derived High Surface Area Nanoporous Carbon Materials with Excellent Iodine and Methylene Blue Adsorption Properties

2019 ◽  
Vol 5 (1) ◽  
pp. 10 ◽  
Author(s):  
Lok Shrestha ◽  
Mamata Thapa ◽  
Rekha Shrestha ◽  
Subrata Maji ◽  
Raja Pradhananga ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Surface Area ◽  
Rice Husk ◽  
Carbon Materials ◽  
High Surface ◽  
High Surface Area ◽  
Nanoporous Carbon ◽  
Adsorption Properties ◽  
Methylene Blue Adsorption ◽  
Nanoporous Carbon Materials

Iodine and methylene blue adsorption properties of the high surface area nanoporous carbon materials derived from agro-waste and rice husk is reported. Rice husk was pre-carbonized at 300 °C in air followed by leaching out the silica nanoparticles by extraction with sodium hydroxide solution. The silica-free rice husk char was mixed with chemical activating agents sodium hydroxide (NaOH), zinc chloride (ZnCl2), and potassium hydroxide (KOH) separately at a mixing ratio of 1:1 (wt%) and carbonized at 900 °C under a constant flow of nitrogen. The prepared carbon materials were characterized by scanning electron microscopy (SEM), Fourier transformed-infrared spectroscopy (FT-IR), powder X-ray diffraction (pXRD), and Raman scattering. Due to the presence of bimodal micro- and mesopore structures, KOH activated samples showed high specific surface area ca. 2342 m2/g and large pore volume ca. 2.94 cm3/g. Oxygenated surface functional groups (hydroxyl, carbonyl, and carboxyl) were commonly observed in all of the samples and were essentially non-crystalline porous particle size of different sizes (<200 μm). Adsorption study revealed that KOH activated samples could be excellent material for the iodine and methylene blue adsorption from aqueous phase. Iodine and methylene blue number were ca. 1726 mg/g and 608 mg/g, respectively. The observed excellent iodine and methylene blue adsorption properties can be attributed to the well-developed micro- and mesopore structure in the carbon material. This study demonstrates that the agricultural waste, rice husk, and derived nanoporous carbon materials would be excellent adsorbent materials in water purifications.

scholarly journals Nanoarchitectonics of Nanoporous Carbon Materials in Supercapacitors Applications

Nanomaterials ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 639 ◽  
Author(s):  
Rekha Goswami Shrestha ◽  
Subrata Maji ◽  
Lok Kumar Shrestha ◽  
Katsuhiko Ariga
Keyword(s):  
Surface Area ◽  
High Performance ◽  
Carbon Materials ◽  
Nanoporous Carbon ◽  
Agricultural Wastes ◽  
Superior Performance ◽  
Nanoporous Structure ◽  
Porous Carbons ◽  
Hierarchical Porous ◽  
Nanoporous Carbon Materials

High surface area and large pore volume carbon materials having hierarchical nanoporous structure are required in high performance supercapacitors. Such nanoporous carbon materials can be fabricated from organic precursors with high carbon content, such as synthetic biomass or agricultural wastes containing cellulose, hemicellulose, and lignin. Using recently developed unique concept of materials nanoarchitectonics, high performance porous carbons with controllable surface area, pore size distribution, and hierarchy in nanoporous structure can be fabricated. In this review, we will overview the recent trends and advancements on the synthetic methods for the production of hierarchical porous carbons with one- to three-dimensional network structure with superior performance in supercapacitors applications. We highlight the promising scope of accessing nanoporous graphitic carbon materials from: (i) direct conversion of single crystalline self-assembled fullerene nanomaterials and metal organic frameworks, (ii) hard- and soft-templating routes, and (iii) the direct carbonization and/or activation of biomass or agricultural wastes as non-templating routes. We discuss the appealing points of the different synthetic carbon sources and natural precursor raw−materials derived nanoporous carbon materials in supercapacitors applications.

Bimetal-organic-framework derived CoTiO3/C hexagonal micro-prisms as high-performance anode materials for Metal ion batteries

2021 ◽  
Author(s):  
Baixue Ouyang ◽  
Tao Chen ◽  
Ran Qin ◽  
Penggao Liu ◽  
Xiaowen Fan ◽  
...  
Keyword(s):  
Metal Ion ◽  
Anode Materials ◽  
High Performance ◽  
Electrode Materials ◽  
Carbon Materials ◽  
Fast Rate ◽  
Low Cost ◽  
Rate Capability ◽  
Small Strain ◽  
Operating Voltage

Titanium based oxides are pomising electrode materials due to the appropriate operating voltage, small strain expansion, fast rate capability, safety, and low cost. Carbon materials exhibit a high cyclic stability...

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