@article { ISI:000329479500021, title = {Magnetism in disordered carbon as a function of the extent of graphitization}, journal = {Solid State Communications}, volume = {177}, year = {2014}, month = {JAN}, pages = {89-94}, publisher = {PERGAMON-ELSEVIER SCIENCE LTD}, address = {THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND}, abstract = {

Magnetic properties of disordered carbon have been investigated as a function of the extent of graphitization. It is found that the magnetization of the disordered carbon decreases with increasing degree of graphitization. Treatment with acid modifies the magnetic characteristics considerably and the original magnetic characteristics are retained upon further heat treatment. The results show that the intrinsic magnetic behavior of the disordered carbon depends on the microstructure and that the edge states play a critical role in deciding the magnetic interactions in the amorphous carbon system. (C) 2013 Elsevier Ltd. All rights reserved.

}, keywords = {Amorphous carbon, disordered carbon, Graphitization, magnetic properties}, issn = {0038-1098}, doi = {10.1016/j.ssc.2013.09.037}, author = {Raj, K. Govind and Joy, Pattayil Alias} } @article {44014, title = {Influence of carbon based supports on selectivity behavior of diols and propanol in Ru catalyzed glycerol hydrogenolysis}, journal = {Applied Catalysis B: Environmental}, volume = {204}, year = {2017}, month = {MAY}, chapter = {134-146}, abstract = {

Activated carbon (AC) and three graphite materials were studied as supports for Ru catalyzed glycerol hydrogenolysis to propanediols and 1-propanol. Structural characteristics of AC and graphite materials were found to greatly affect the reducibility and particle size of supported Ru and hence, the activity and product distribution in glycerol hydrogenolysis. XRD of graphite materials showed distinctly (002) plane having highly organized layered structure and the peak intensity decreased in the order of Ru/KS150 \> Ru/HSAG100 \> Ru/KS6 due to decrease in the graphite sheet thickness. In Raman, the intense D band in HSAG100 compared to that in KS6 and KS150 samples indicated its highly amorphous nature or mixed carbon hybridization. Glycerol conversion for Ru on AC was higher than that on graphite and among different graphites, it showed a descending activity order of Ru/KS6 \> Ru/HSAG100 \> Ru/KS150. The product distribution for AC and HSAG100 supported Ru was similar, giving 1-propanol (45\%) alongwith 1,2-propanediol (1,2-PDO) (37\%) and 1,3-propanediol (1,3-PDO) (9{\textendash}11\%). For graphite supports, availability of Ru although bigger in size (4{\textendash}5 nm), would be higher on the surface than in case of AC which formed deep hydrogenolysis products like 1-, 2- propanol, ethanol etc.

}, keywords = {activated carbon, Amorphous carbon, catalysis, Glycerol, Glycerol conversions, Glycerol hydrogenolysis, graphite composites, Graphite supports, Hydrogenolysis, Hydrolysis, layered structures, Particle size, Product distributions, Propanediols, Propanol, Selectivity behavior, Structural characteristics, Structural effect, Structural effects}, issn = {0926-3373}, doi = {10.1016/j.apcatb.2016.11.032}, author = {Mane, Rasika B. and Patil, S. and Shirai, Masayuki and Rayalu, Sadhana S. and Rode, Chandrashekhar V.} } @article {47372, title = {Synthesis of graphene from activated carbon at liquid nitrogen temperature and its detailed structural analysis}, journal = {Applied Physics A-Materials Science \& Processing}, volume = {127}, year = {2021}, month = {MAY}, pages = {319}, type = {Article}, abstract = {

The present study deals with the synthesis of graphene using thermal quenching of pre-heated activated carbon (a-C) (1370 K for 3 h) at liquid nitrogen temperature and its detailed structural analysis using XRD, TEM, FTIR and Raman spectroscopy. The analysis of lattice parameters (L-a, L-c,L- and d) of constituent nanographitic domains using XRD shows restoration of graphene-like structure in the resultant product (a-CL). TEM image reveals porosity and partially crystallinity (from SAED) in a-C. While thin layers of graphene are observed in the TEM images of a-CL Deconvoluted Raman spectra have been used to investigate the evolution of crystalline behaviour of a-C with temperature in view of Ferrari and Robertson{\textquoteright}s three-stage model. The evolution of G peak and increase in I-D/I-G reveals restoration of crystallinity in a-CL. The development of the D peak indicates disordering of graphite but ordering of amorphous carbon. The reported method is technologically beneficial for graphene synthesis for large number of applications such as supercapacitors, H-2 storage, gas separation and purification.

}, keywords = {activated carbon, Amorphous carbon, graphene, H-2 storage applications, Raman spectroscopy, Supercapacitors}, issn = {0947-8396}, doi = {10.1007/s00339-021-04416-w}, author = {Sharma, Preeti and Sharma, Geeta and Punia, Rajesh} }