Green Synthesis of Graphene Oxide and Reduced Graphene Oxide for the Use in Opto-Electronic and Thin Film Applications
General Material Designation
[Thesis]
First Statement of Responsibility
Fahey, Marshall Justin
Subsequent Statement of Responsibility
Kim, Young-Gi
.PUBLICATION, DISTRIBUTION, ETC
Name of Publisher, Distributor, etc.
Delaware State University
Date of Publication, Distribution, etc.
2020
PHYSICAL DESCRIPTION
Specific Material Designation and Extent of Item
110
DISSERTATION (THESIS) NOTE
Dissertation or thesis details and type of degree
M.S.
Body granting the degree
Delaware State University
Text preceding or following the note
2020
SUMMARY OR ABSTRACT
Text of Note
The development of opto-electronic and thin film materials revolutionized the modern world by ushering in an age where photovoltaic cells can be printed, automobiles can stop themselves and your electronic devices can be unlocked by a smile. Recently, graphene oxide (GO), reduced graphene oxide (rGO) and perovskites have shown to be promising candidates for opto-electronic and thin film applications. However, each material has its own hazards: GO synthesis produces toxic nitrous oxide species (NOx) and the final product is dependent upon the quality and size of the starting material; rGO utilizes hydrazine which is flammable and a possible carcinogen; traditional perovskite materials utilize and contain lead, which present a health and environmental concern. This work synthesized GO via the Improved Hummers' Method in order to reduce the over-oxidation of graphite sheets and to remove the toxic NOx side products, while varying the pre-oxidation steps to reduce the graphitic character of the final product. Green reduction of GO to rGO was accomplished by removing hydrazine while effectively reducing with L-ascorbic acid at mild conditions. Lead was replaced by another group IV element, tin, resulting in the double perovskite cesium tin iodide (Cs2SnI6). Both GO and rGO were characterized via FTIR spectroscopy, UV-Vis spectroscopy, Raman spectroscopy, scanning electron microscopy, x-ray diffraction, and zeta potential analysis, which revealed that the graphite starting material was partially oxidized in differing degrees dependent upon the pre-oxidation steps. rGO materials were found to have removed all oxygen functional groups, but alcohol and epoxides. rGO materials were then functionalized with silver nanoparticles and characterized via UV-Vis spectroscopy, Raman spectroscopy, scanning electron microscopy and zeta potential analysis. Perovskite materials were characterized via UV-Vis spectroscopy, Raman spectroscopy, scanning electron microscopy and x-ray diffraction.