硫酸對氧化石墨烯結構的影響

Abstract

本研究分為(一)不同的硫酸濃度對GO 進行反應與(二)稀硫酸濃 度0.6M 對GO 進行不同的反應時間。 利用粉末X 光繞射儀、拉曼散射儀、X 光光電子能譜儀和四點 探針等儀器鑑定，對其材料進行分析。結構上，根據拉曼散射的D band 和G band 之比值可以得知材料的石墨化程度。隨著硫酸濃度增加至 18M，ID/IG 比值會從2.17 下降至1.46，表示脫水還原形成石墨烯。 然而，在稀硫酸0.6M 反應1.5 小時，GO 結構會進行開環，ID/IG 比值 從2.17 上升至2.89，表面缺陷增加；24 小時則會進行部份脫水還原， ID/IG 比值從2.17 下降至1.71。電性上，隨著硫酸濃度的提升，導電 率從1.67×10-3S/m 提升至1.40×102S/m，由於高濃度的硫酸對GO 進 行脫水反應，使原本GO 表面的含氧官能基部分脫去，導電性因此變 高；然而0.6M 稀硫酸對GO 反應時間的增加，導電率從1.67×10-3S/m 提升至5.73×10-2S/m。 此研究是硫酸對GO 的時間和濃度影響，因此結果可提供以環 保的方式製備石墨烯以及GO 的結構修飾，作為重要的參考價值。

This thesis consists of two parts which are related to the treatment of graphene oxides (GO) with H2SO4. The first part focuses on the reaction of GO in solution of H2SO4 with various concentrations. The second part reports the study for the reaction of GO in 0.6M H2SO4 for different reaction time. The GO and GO-related materials were characterized with powder X-ray diffraction, Raman spectrometry, X-ray photoelectron spectroscopy and four probes measurement. According to Raman spectrometry, the intensity ratio of D- and G-band (ID/IG) provides the degree of graphitization of GO after treatment in solution of H2SO4. GO was treated in a solution of 18 M H2SO4 for 1.5 hr and the value of ID/IG decreased from 2.17 to 1.46 because the hydroxyl groups were removed by the reaction of dehydration. The ratio of ID/IG decreases with the increase the concentration of H2SO4. GO mainly undergoes the ring-opening reactions of epoxyl groups in 0.6M H2SO4 at the initial period and the value of ID/IG is 2.89 for the GO after a reaction time of 1.5 hr. The prolonged reaction decreases the value of ID/IG to 1.71, due to the reduction of defects. The electrical measurements also indicates that the conductivity of GO increases from 1.67×10-3 S/m to 1.40×102 S/m after the reaction with 18 M H2SO4 for 1.5 hr, consistent with measurements of Raman spectroscopy. However, the conductivity of GO increases only up to 5.73× 10-2S/m after treatment in 0.6 M H2SO4 for 24 hr. This thesis provides a environmental method of synthesizing graphene and modification of GO’s framework. It is an important viewpoint for producing graphene .