以湖南新化、郴州两地不同石墨化程度的煤系隐晶质石墨为原料,采用改进Hummers法,制备出系列氧化石墨,然后利用x射线衍射(XRD)、扫描电镜(SEM)、傅里叶变换红外光谱(FT—IR)等对石墨原料及系列氧化产物进行表征。结果表明,经氧化后两个地区石墨化不同的石墨结构层上均接有羟基(C—OH)、环氧(C-O-c)、羧基(COOH)或羰基(C=O)等含氧官能团,高锰酸钾的用量和原矿的石墨化程度对氧化石墨的难易和产物的结构无序程度均有影响。低石墨化程度的石墨较高石墨化程度的石墨易于被氧化。随着KMnO4用量的增加,两种石墨的结构无序程度都逐渐增加,但在相同的KMnO4用量下,低石墨化度的石墨氧化产物的结构无序程度更高。推测一方面是隐晶质石墨的粒径偏小,与高锰酸钾及溶液的接触面积较大,另一方面是低石墨化度石墨C—C多,化学活性较强,易被氧化。此外,高石墨化程度的石墨氧化后的最大层间距大于低石墨化度石墨氧化后的最大层间距。
The Hunan Chenzhou and Xinhua graphite with different graphitization degree were oxidized by the modified Hummers method usingdifferent amounts of oxidizingagent(KMnO4),X-ray diffraction (XRD),Scanning electron microscope(SEM), Fourier transform infrared (FT-IR) spectroscopy, Raman spectroscopy(Raman) ,Transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) , The testing methods were used to study the structure of graphite samples and their oxidation products.The results showed that the hydroxyl group (C-OH), ethylene (C-O-C) and carboxyl group (COOH) were connected to the graphite layersduring the course of oxidation, but the graphite with lower graphitization degree was easier to be oxidized when the amount of usedKMnO4 is lower;While the graphite with higher graphitization degree was easier to be oxidized when using more oxidizing agent.With the increase of the amount of KMnO4, the structure disorder degree of the two kinds of graphite increased gradually.But under the same amount of KMnO4, the oxidation productof graphitewith low graphitization degree had higher degree of disorder.It can be speculated that:On the one hand,the contact area ofgraphite with potassium permanganate and solution is larger due to the particle size of graphite with low-degree of metamorphismis smaller;On the other hand, the graphite with low degree of graphitization has more C -C and easily oxidizeddue to its high chemical activity.