Kinetics of hydrazine reduction of thin films of graphene oxide and the determination of activation energy by the measurement of electrical conductivity

RSC Advances ◽  
2015 ◽  
Vol 5 (124) ◽  
pp. 102567-102573 ◽  
Author(s):  
Seo Gyun Kim ◽  
Soon Sik Lee ◽  
Eunsu Lee ◽  
Jinhwan Yoon ◽  
Heon Sang Lee
Keyword(s):  
Thin Films ◽  
Activation Energy ◽  
Electrical Conductivity ◽  
Graphene Oxide ◽  
Reduction Reaction ◽  
Hydrazine Reduction ◽  
Electrical Conductivities ◽  
Kinetics Of ◽  
Pet Films

By measurement of the electrical conductivities of GO coated PET films during the reduction reaction, we determined activation energy.

Electrodeposited Iron(III) Oxide (α-Fe2O3) Thermoelectric Thin Films

2016 ◽  
Vol 701 ◽  
pp. 23-27 ◽  
Author(s):  
Mohd Zuhri Shaiful Azni ◽  
Ho Kee Tan ◽  
Pei Ling Low ◽  
Nisha Kumari Devaraj ◽  
Boon Hoong Ong ◽  
...  
Keyword(s):  
Thin Films ◽  
Electrical Conductivity ◽  
Deposition Time ◽  
Deposition Potential ◽  
Electrical Conductivities ◽  
Potentiostatic Electrodeposition ◽  
Layered Growth ◽  
Time Parameters ◽  
Thermoelectric Thin Films ◽  
Deposited Films

α-Fe2O3 thermoelectric thin films were electrodeposited onto copper substrates using chloride-based electrolytes by means of potentiostatic electrodeposition. The influence of several electrodeposition parameters on the surface morphology, elemental composition and electrical conductivity of the deposited films was studied and analyzed. The deposits formed porous, wire-like morphology, with the smallest width measured to be ~60 nm. The wires tend to aggregate to form clusters, in addition to multi-layered growth of the wires. Between the parameters studied, electrolyte concentration and deposition time parameters have higher influences on the electrical conductivity of the deposited films, with the increment up to two fold higher. Deposition potential parameter offered the lowest capability to improve on the electrical conductivity in addition to the non-uniform distribution of the measured electrical conductivities. The tunable electrical conductivity is favorable for improving the performance of α-Fe2O3 films for thermoelectric applications.

Ion chromatographic determination of hydrazine in excess ammonia for monitoring graphene oxide reduction reaction

Talanta ◽  
2019 ◽  
Vol 205 ◽  
pp. 120081 ◽  
Author(s):  
Aleksandra N. Koreshkova ◽  
Vipul Gupta ◽  
Anton Peristyy ◽  
Pavel N. Nesterenko ◽  
Thomas Rodemann ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Chromatographic Determination ◽  
Reduction Reaction ◽  
Oxide Reduction

Structural, Electrical and Optical Properties of Laser Deposited Thin Films of Srco0.8Fe0.2O3-δ

1994 ◽  
Vol 369 ◽  
Author(s):  
C. Zhang ◽  
H. Deng ◽  
J. Varon ◽  
B. Abeles ◽  
Y. Yang ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Activation Energy ◽  
Electrical Conductivity ◽  
Optical Properties ◽  
Optical Absorption ◽  
Laser Deposition ◽  
Electrical And Optical Properties ◽  
Thermally Activated ◽  
Characteristic Features

AbstractThin film SrCo0.8Fe0.2O3-δ were made by pulse laser deposition. The electrical conductivity is thermally activated in the temperature 25-500 °C with an activation energy of 0.17-0.19 eV and is temperature independant from 500-800 °C. The optical absorption shows characteristic features which are interpreted qualitatively in terms of a simple band structure diagram.

Electrical conductivity and crystallization kinetics of amorphous Ag10Te90 and Ag20Te80 thin films

2008 ◽  
Vol 10 (10) ◽  
pp. 1416-1421 ◽  
Author(s):  
A. Abu El-Fadl ◽  
M.M. Hafiz ◽  
M.M. Wakkad ◽  
A.S. Aashour
Keyword(s):  
Thin Films ◽  
Electrical Conductivity ◽  
Crystallization Kinetics ◽  
Kinetics Of

Synthesis and Determination of the Kinetic Parameters for Non-Isothermal Decomposition of Complexes Ln(thd)3phen

2006 ◽  
Vol 530-531 ◽  
pp. 506-512 ◽  
Author(s):  
Wilton Silva Lopes ◽  
Crislene Rodrigues da Silva Morais ◽  
A.G. de Souza
Keyword(s):  
Activation Energy ◽  
Thermal Decomposition ◽  
Lanthanide Complexes ◽  
Reaction Order ◽  
Decomposition Reaction ◽  
Cylindrical Symmetry ◽  
Boundary Reaction ◽  
Phase Boundary Reaction ◽  
Kinetics Of

In this work the kinetics of the thermal decomposition of two ß-diketone lanthanide complexes of the general formula Ln(thd)3phen (where Ln = Nd+3 or Tm+3, thd = 2,2,6,6- tetramethyl-3,5-heptanodione and phen = 1,10-phenantroline) has been studied. The powders were characterized by several techniques. Thermal decomposition of the complexes was studied by non-isothermal thermogravimetry techniques. The kinetic model that best describes the process of the thermal decomposition of the complexes it was determined through the method proposed by Coats-Redfern. The average values the activation energy obtained were 136 and 114 kJ.mol-1 for the complexes Nd(thd)3phen and Tm(thd)3phen, respectively. The kinetic models that best described the thermal decomposition reaction the both complexes were R2. The model R2 indicating that the mechanism is controlled by phase-boundary reaction (cylindrical symmetry) and is defined by the function g(α) = 2[1-(1-a)1/2], indicating a mean reaction order. The values of activation energy suggests the following decreasing order of stability: Nd(thd)3phen > Tm(thd)3phen.

Enhancement of Aurivillius Phase Formation Kinetics in SBT Thin Films using Nanoparticle Seeding

2003 ◽  
Vol 784 ◽  
Author(s):  
Yun-Mo Sung ◽  
Woo-Chul Kwak ◽  
Se-Yon Jung ◽  
Seung-Joon Hwang
Keyword(s):  
Thin Films ◽  
Activation Energy ◽  
Phase Transformation ◽  
Phase Formation ◽  
X Ray Diffraction ◽  
Aurivillius Phase ◽  
X Ray ◽  
Si Substrates ◽  
Formation Kinetics ◽  
Kinetics Of

ABSTRACTPt/Ti/SiO2/Si substrates seeded by SBT nanoparticles (∼60–80 nm) were used to enhance the phase formation kinetics of Sr0.7Bi2.4Ta2O9 (SBT) thin films. The volume fractions of Aurivillius phase formation obtained through quantitative x-ray diffraction (Q-XRD) analyses showed highly enhanced kinetics in seeded SBT thin films. The Avrami exponents were determined as ∼1.4 and ∼0.9 for unseeded and seeded SBT films, respectively, which reveals different nucleation modes. By using Arrhenius–type plots the activation energy values for the phase transformation of unseeded and seeded SBT thin films were determined to be ∼264 and ∼168 kJ/mol, respectively. This gives a key reason to the enhanced kinetics in seeded films. Microstructural analyses on unseeded SBT thin films showed formation of randomly oriented needle-like crystals, while those on seeded ones showed formation of domains comprised of directionally grown worm-like crystals.

scholarly journals Torrefaction of Sewage Sludge: Kinetics and Fuel Properties of Biochars

Energies ◽  
2019 ◽  
Vol 12 (3) ◽  
pp. 565 ◽  
Author(s):  
Jakub Pulka ◽  
Piotr Manczarski ◽  
Jacek Koziel ◽  
Andrzej Białowiec
Keyword(s):  
Activation Energy ◽  
Sewage Sludge ◽  
Thermal Transformation ◽  
Fuel Properties ◽  
Process Time ◽  
Technological Aspect ◽  
Heating Value ◽  
Valuable Product ◽  
Kinetics Of

We propose a ‘Waste to Carbon’ thermal transformation of sewage sludge (SS) via torrefaction to a valuable product (fuel) with a high content of carbon. One important, technological aspect to develop this concept is the determination of activation energy needed for torrefaction. Thus, this research aimed to evaluate the kinetics of SS torrefaction and determine the effects of process temperature on fuel properties of torrefied products (biochars). Torrefaction was performed using high ash content SS at six (200~300 °C) temperatures and 60 min residence (process) time. Mass loss during torrefaction ranged from 10~20%. The resulting activation energy for SS torrefaction was ~12.007 kJ·mol−1. Initial (unprocessed) SS higher heating value (HHV) was 13.5 MJ·kg−1. However, the increase of torrefaction temperature decreased HHV from 13.4 to 3.8 MJ·kg−1. Elemental analysis showed a significant decrease of the H/C ratio that occurred during torrefaction, while the O/C ratio fluctuated with much smaller differences. Although the activation energy was significantly lower compared with lignocellulosic materials, low-temperature SS torrefaction technology could be explored for further SS stabilization and utilization (e.g., dewatering and hygienization).

Kinetics of Magnetic Relaxation and Determination of Activation Energy in High-$\bf {\mbi T}_{c}$ Superconductors

1994 ◽  
Vol 33 (Part 2, No. 6B) ◽  
pp. L843-L845
Author(s):  
Xiao-Guang Li ◽  
Ryu Kobayashi ◽  
Yasutoshi Kotaka ◽  
Jun-ichi Shimoyama ◽  
Kohji Kishio
Keyword(s):  
Activation Energy ◽  
Magnetic Relaxation ◽  
Kinetics Of

scholarly journals Desorption characteristics and kinetic parameters determination of molecular sieve by thermogravimetric analysis/differential thermogravimetric analysis technique

2018 ◽  
Vol 36 (7-8) ◽  
pp. 1389-1404 ◽  
Author(s):  
Yalou Guo ◽  
Hui Zhang ◽  
Yingshu Liu
Keyword(s):  
Activation Energy ◽  
Thermogravimetric Analysis ◽  
Heating Rates ◽  
Carrier Gas ◽  
Zeolite 13X ◽  
Analysis Technique ◽  
Desorption Activation Energy ◽  
Differential Thermogravimetric Analysis ◽  
Kinetics Of

The kinetics of the thermal desorption of CO2 adsorbed on zeolite 13X were obtained using a differential thermogravimetric analyser under two different carrier gas conditions. The varying heating rates were set as 8, 12, 16, and 20 K min−1, respectively. The desorption activation energy of the physisorption sites for this experiment evaluated by an integral method without prediction of the reaction order ranged from 12.15 to 14.12 kJ mol−1 (CO2 as the carrier gas) and 43.32 to 50.42 kJ mol−1 (Ar as the carrier gas), respectively. The desorption activation energy of the chemisorption sites ranged from 57.95 to 58.53 kJ mol−1 (CO2 as the carrier gas) and 74.02 to 79.92 kJ mol−1 (Ar as the carrier gas), respectively.

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