Magnetism in graphene oxide nanoplatelets: The role of hydroxyl and epoxy bridges

Graphene Oxide: Comparisons between Experimental and Computational Simulation of HR-TEM Images

“…The GO samples were morphologically and structurally characterized by transmission electron microscopy (TEM) and high-resolution (HR)-TEM images, obtained by using the Tecnai F20 Super Twin TMP on a FEI microscope operating at 80 kV and equipped with a Cs image corrector and a Gatan Tridiem spectrometer; for more details, see [41][42][43].…”

“…Also, experimental and simulated GO structure -HR-TEM micrographs revealed random defect density distribution in all micrographs. As reported before [41,42], defect density was determined by employing Raman spectral analysis results in GO samples. It was estimated that GO samples with 5.3% oxide coverage exhibit a value of 6.0 × 10 −4 cm −2 , as defect density [41,42].…”

“…By comparing standard deviations and mean values in both images, it was determined that simulated HR-TEM micrographs agree with the experimental HR-TEM micrographs by 64.68%, approximately, which is a good value considering the great atomistic arrangement of 7,479 atoms involved here in the simulated HR-TEM image, as presented in Figure 1(b). The experimental presence of hydroxyl and epoxy functional groups in GO nanoplatelet sample were identificated by using XPS and FTIR spectroscopies, as reported [41][42][43], and the theoretical molecular identification of hydroxyl and epoxy functional groups were carried out by employing the molecular configuration of GO presented in Figure 2.…”

“…The transport properties of GO can be influenced by the multilayered configuration [16] and presence of defects [17]. All these effects can be exploited in different fields [18] and applications from batteries [19][20][21][22], energy storage [23][24][25], electronics [26][27][28][29][30][31][32][33], catalysis [34], metal sorption [35], hydrogen storage [36], as well as to obtain graphene oxide monolayers [37][38][39][40][41][42][43][44], films, fibers, and membranes [45].…”

“…These methods are excellent for basic research. However, the double-thermal decomposition method in a pyrolysis system has proven to be a low-cost alternative and eco-friendly technique to synthesize stable graphene oxide multilayers, using bamboo waste products as source material at higher temperatures from 573 to 973 K; very different compared to traditional methods, as reported [41][42][43][44]. Higher temperatures promote elimination of organic compounds and oxygen functional groups, inducing formation of hydroxyl and epoxy bridges as multifunctional groups, leading to improvement in the crystal structure and positively impacting on the thermal, electrical, and magnetic transport [41][42][43][44][45][46][47][48][49][50].…”