scholarly journals Multifunctional Hierarchically Architectured ZnO for Luminescence, Photocatalytic, Electrocatalytic, and Energy Storage Applications

Crystals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1025
Author(s):  
V. P. Singh ◽  
Mirgender Kumar ◽  
B. Purusottam Reddy ◽  
Sunny ◽  
R. K. Gangwar ◽  
...  
Keyword(s):  
Energy Storage ◽  
Waste Water Treatment ◽  
Positron Annihilation Spectroscopy ◽  
X Ray Diffraction ◽  
Supercapacitor Electrode ◽  
Intermediate Phases ◽  
Coprecipitation Technique ◽  
Energy Storage Applications ◽  
White Luminescence ◽  
Highly Porous

Hierarchically ZnO nanoarchitecture synthesized through coprecipitation technique. Growth process has been analyzed by varying pH from 5.5 to 13 along with post heat treatment process through the observation of surface morphology from 2D plates, triangular, hexagonal rods, needles, and finally to hierarchical. X-ray diffraction (XRD) reveals many intermediate phases along with ZnO which has been eliminated through the proper pH and temperature. The native defects have been discussed by using Raman and positron annihilation spectroscopy. Further, multifunctional properties of synthesized material have been discussed by candle-like warm white luminescence, photocatalysis, electrocatalysis and energy storage applications. Specially hierarchically nanoarchitecture found suitable for warm white lighting along with effective for waste water treatment by visible light. The highly porous property of the same material made itself appropriate for effective oxygen evaluation reaction and hydrogen evolution reaction together with reduced overpotential and Tafel slope. The application for supercapacitor electrode (~780 F/g) also has been revealed which opened new dimension for hierarchical ZnO.

Hydrothermal synthesis of Fe3O4/RGO composites and investigation of electrochemical performances for energy storage applications

RSC Advances ◽  
2014 ◽  
Vol 4 (84) ◽  
pp. 44777-44785 ◽  
Author(s):  
Sanjit Saha ◽  
Milan Jana ◽  
Pranab Samanta ◽  
Naresh Chandra Murmu ◽  
Nam Hoon Kim ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Energy Storage ◽  
Hydrothermal Synthesis ◽  
Hydrothermal Method ◽  
Reduced Graphene Oxide ◽  
Electrochemical Performances ◽  
Reduced Graphene ◽  
One Step ◽  
Energy Storage Applications ◽  
Highly Porous

Highly porous nano-structured Fe3O4 particles were successfully prepared on the surface of reduced graphene oxide (RGO) sheets through a one-step hydrothermal method.

scholarly journals Crystal Defects and Cation Redistribution Study on Nanocrystalline Cobalt-Ferri-Chromites by Positron Annihilation Spectroscopy

2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
Kunal B. Modi ◽  
Nimish H. Vasoya ◽  
Vinay K. Lakhani ◽  
Tushar K. Pathak ◽  
P. M. G. Nambissan
Keyword(s):  
Spinel Ferrite ◽  
Positron Annihilation Spectroscopy ◽  
Crystal Defects ◽  
X Ray Diffraction ◽  
Lattice Contraction ◽  
General Chemical ◽  
Coprecipitation Technique ◽  
Normal Spinel ◽  
Cation Redistribution ◽  
Subsequent Stabilization

Positron lifetime and Doppler broadening measurements were carried out on nanocrystalline (grain size ~60–65 nm) samples of the Cr3+-substituted cobalt ferrite system with general chemical formula CoCrxFe2−xO4 (x=0.0−2.0) synthesized by the coprecipitation technique. The results indicated selective trapping of positrons in large vacancy clusters initially at the tetrahedral (A-) sites and then with Cr3+-substitution up to concentration (x)=0.7, at the octahedral (B-) sites. The results are consistent with the cation distribution determined from X-ray diffraction line intensity calculations, which indicated partial inversion of the inverse spinel ferrite, subsequent stabilization over a range of substitution (x=0.7 to 1.7), and finally the full inversion to the normal spinel chromite (CoCr2O4, x=2.0). In the intermediate range of substitution, lattice contraction prevented a fraction of Co2+ ions released from the (B-) sites from entering the tetrahedral sites, and these vacancies at the (A-) sites trapped positrons. Although the samples were composed of nanocrystalline grains, only an insignificant fraction of positrons were diffused and annihilated at the grain surfaces, since the grain sizes and the thermal diffusion length of positrons nearly overlapped.

scholarly journals Development of Ti/Ni Nanolayered Structures to Be a New Candidate for Energy Storage Applications

2020 ◽  
Vol 10 (19) ◽  
pp. 6935
Author(s):  
Osama Saber ◽  
Sajid Ali Ansari ◽  
Adil Alshoaibi
Keyword(s):  
Energy Storage ◽  
Double Layer ◽  
Layer Structure ◽  
Morphological Characteristics ◽  
Building Blocks ◽  
Interplanar Distance ◽  
Energy Storage Devices ◽  
Supercapacitor Electrode ◽  
Double Layer Structure ◽  
Energy Storage Applications

Development of electrochemical supercapacitor electrode is the best way to improve the performance and conductivity of the alone materials and support energy storage devices. In this work, cyanate anions have used as building blocks to build series of nanolayered materials based on Ti/Ni layered double hydroxides (LDHs). The structural and morphological characteristics of the prepared Ti/Ni LDHs were examined using different techniques. The electrochemical supercapacitive behavior of the prepared LDHs was observed in the three-assembly electrochemical cell. These results showed that the optimized ratio of the nickel and titanium plays an important role to enhance the electrochemical performance of the LDHs. The optimized Ti/Ni LDHs, which has the highest content of titanium, showed the highest specific capacitance (675 F/g) value. In this trend, this LDH also retain a high percentage of the cyclic retention after long cyclic charging-discharging process. The enhanced performance could be due to the double layer structure, enough interplanar distance between the layer, and large number of exposed active site within the double layer structure of the LDHs. Finally, although there are no reports for the electrochemical supercapacitive performance of Ti/Ni LDHs in the literature, it is interesting to produce a new candidate for energy storage applications.

scholarly journals Graphene-Based Materials for Supercapacitor

2021 ◽  
Author(s):  
Abu Jahid Akhtar
Keyword(s):  
Electrical Conductivity ◽  
Energy Storage ◽  
Mechanical Behaviour ◽  
Electrode Materials ◽  
Two Dimensional ◽  
Supercapacitor Electrode ◽  
Graphene Layers ◽  
Ideal Candidate ◽  
Energy Storage Applications ◽  
Supercapacitor Electrode Materials

Graphene, a one-atomic-thick film of two-dimensional nanostructure, has piqued the attention of researchers due to its superior electrical conductivity, large surface area, good chemical stability, and excellent mechanical behaviour. These extraordinary properties make graphene an appropriate contender for energy storage applications. However, the agglomeration and re-stacking of graphene layers due to the enormous interlayer van der Waals attractions have severely hampered the performance of supercapacitors. Several strategies have been introduced to overcome the limitations and established graphene as an ideal candidate for supercapacitor. The combination of conducting polymer (CP) or metal oxide (MO) with graphene as electrode material is expected to boost the performance of supercapacitors. Recent reports on various CP/graphene composites and MO/graphene composites as supercapacitor electrode materials are summarised in this chapter, with a focus on the two basic supercapacitor mechanisms (EDLCs and pseudocapacitors).

Electron Microscopy/Diffraction Study of the Ternary Mn-Er-S System

1990 ◽  
Vol 48 (1) ◽  
pp. 76-77
Author(s):  
A. R. Landa Canovas ◽  
L.C. Otero Diaz ◽  
T. White ◽  
B.G. Hyde
Keyword(s):  
Electron Microscopy ◽  
Gas Flow ◽  
Graphite Crucible ◽  
Nominal Composition ◽  
X Ray Diffraction ◽  
Alumina Crucible ◽  
X Ray ◽  
Intermediate Phases ◽  
Twin Band ◽  
Ar Gas

X-Ray diffraction revealed two intermediate phases in the system MnS+Er2S3,:MnEr2S4= MnS.Er2S3, and MnEr4S7= MnS.2Er2S3. Their structures may be described as NaCl type, chemically twinned at the unit cell level, and isostructural with CaTi2O4, and Y5S7 respectively; i.e. {l13} NaCl twin band widths are (4,4) and (4,3).The present study was to search for structurally-related (twinned B.) structures and or possible disorder, using the more sensitive and appropiate technigue of electron microscopy/diffraction.A sample with nominal composition MnEr2S4 was made by heating Mn3O4 and Er2O3 in a graphite crucible and a 5% H2S in Ar gas flow at 1500°C for 4 hours. A small amount of this material was thenannealed, in an alumina crucible, contained in sealed evacuated silica tube, for 24 days at 1100°C. Both samples were studied by X-ray powder diffraction, and in JEOL 2000 FX and 4000 EX microscopes.

scholarly journals Tailoring of the pore structures of wood pyrolysis chars for potential use in energy storage applications

2021 ◽  
Vol 286 ◽  
pp. 116431
Author(s):  
Przemyslaw Maziarka ◽  
Peter Sommersacher ◽  
Xia Wang ◽  
Norbert Kienzl ◽  
Stefan Retschitzegger ◽  
...  
Keyword(s):  
Energy Storage ◽  
Wood Pyrolysis ◽  
Pore Structures ◽  
Energy Storage Applications ◽  
Potential Use

High energy density aqueous zinc–benzoquinone batteries enabled by carbon cloth with multiple anchoring effects

2021 ◽  
Author(s):  
Zhiqiang Luo ◽  
Silin Zheng ◽  
Shuo Zhao ◽  
Xin Jiao ◽  
Zongshuai Gong ◽  
...  
Keyword(s):  
Energy Storage ◽  
Energy Density ◽  
Porous Carbon ◽  
Large Scale ◽  
High Energy ◽  
High Energy Density ◽  
Carbon Cloth ◽  
Anchoring Effects ◽  
High Theoretical Capacity ◽  
Energy Storage Applications

Benzoquinone with high theoretical capacity is anchored on N-plasma engraved porous carbon as a desirable cathode for rechargeable aqueous Zn-ion batteries. Such batteries display tremendous potential in large-scale energy storage applications.

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