Effect Of Carbonaceous Debris On The Electrochemical Behaviors Of Graphene Oxide And Graphene

It was reported that amount of carbonaceous oxidative debris resided ingraphene oxide prepared from the chemical exfoliation of graphite. Theelectrochemical behaviors of graphene oxide are significantly affected by the presenceof carbonaceous oxidative debris. We find that when graphene oxide is chemicallyreduced to graphene the carbonaceous oxidative debris still reside in graphene sheets.The most important finding is that the carbonaceous debris cause a greatly impact onthe electrochemical behaviors especially the electrocatalysis properties of reducedgraphene oxide. On that account, this dissertation firstly descripts the separation wayand the composition of the carbonaceous oxidative debris in detail. We alsodiscovered the significant impact on the electrochemical behaviors of the chemicallyreduced graphene and electrochemically reduced graphene caused by carbonaceousdebris. The main contents of the dissertation mainly involves the following twosections:(1) We have demonstrated that the electrochemical properties of graphene oxide/electrochemical reduced graphene oxide (graphene) modified electrodes aresignificantly affected by the presence of carbonaceous debris. We selectedβ-nicotinamide adenine dinucleotide (NADH), ascorbic acid (AA), dopamine (DA)and acetaminophen (AP) as the target analyte. However, the effects caused by debrisare very different for graphene oxide compared to reduced graphene oxide. Thepresence of carbonaceous debris is adverse to the electrochemical activities ofgraphene oxide while favorable to those of the reduced graphene oxide.(2) We also have disclosed that there are some carbonaceous debris stronglyadhered to chemically reduced graphene oxide(referred to as graphene). We sepreatedthe carbonaceous debris from the graphene and a series of modern physical tests werecarried out to confirm the composition of it. The results indicate that the carbonaceousdebris mainly consists of oxygen containing polycyclic aromatic compounds. The testalso confirms that the graphene sheets themselves are not altered significantly afterbase washing but the proportion of oxygen-containing functional group is reduced.Afterwards we discussed the effects on the electrochemical behaviors of graphenecaused by carbonaceous debris. We find that it is favorable to the oxidation orreduction of ascorbic acid (AA), β-nicotinamide adenine dinucleotide (NADH),acetaminophen (AP) and hydrogen peroxide (H2O2). Compared with graphite, we demonstrated that after the removal the carbonaceous debris the as-prepared grapheneis not much superior to conventional graphite.