响应面优化法研究还原氧化石墨烯的制备（英文）

Optimization of synthesis for reduced oxidized graphene

采用Hummers法合成氧化石墨烯,并以维生素C作为还原剂制备还原氧化石墨烯。在氧化石墨烯的还原过程中,使用Design-Expert软件,采用响应面优化法综合分析反应时间、反应温度、反应物配比(维生素C与氧化石墨烯的质量比)对还原氧化石墨烯导电性的影响,并建立了还原氧化石墨烯电导率的预测模型。回归模型和响应面分析结果表明,氧化石墨烯的最优还原工艺参数为:反应时间为2h、反应温度为95℃、反应物配比为13。验证试验所制备的还原氧化石墨烯(rGOm)的电导率为10.326s/cm,与理论预测值的拟合度较高,说明电导率的预测模型合理、有效。所得产物的拉曼光谱、X射线衍射、紫外可见吸收光谱分析结果表明,试验制得还原氧化石墨烯质量较高。

In this study, response surface methodology was used to optimize the reduction conditions for graphene oxide （GO）, and an environmentally-friendly approach for preparing reduced graphene oxide （rGO） was performed by using vitamin C as a reductant. The GO was prepared by oxidation of natural graphite via modified Hummers＇ method, and then the rGO suspensions were developed by using vitamin C. The key factors during the reduction process of graphene oxide, including reaction time, reaction temperature and reactants ratio, were analyzed by the Box-Behnken design of experiments using Design-Expert software with three independent variables and three levels. Meanwhile, the structure and morphology of the obtained rGO were characterized by the four-probe method, raman spectra, UV-vis spectra and XRD spectra. The obtained regression equation was significant （P = 0. 000 5 ）, which could be used to predict the electrical conductivity of the obtained rGO according to preparation conditions. Based on the regression equation and response surface analysis, the response variable, namely, electrical conductivity was statistically analyzed by using a response surface methodology and two-way analysis of variance. The results showed that the reaction temperature and reactants ratio were significant factors affecting the electrical conductivity value, whereas the reactants time was the insignificant factor. The interaction effects between the reaction temperature and reaction time were remarkable. The optimal reduction process conditions were determined to be 95℃, 2 h, and vitamin C to graphene oxid ratio of 13. The rGO with good electrical conductivity was prepared under the optimal reducing technological conditions. The electrical conductivity of the rGO obtained from the confirmatory test （ rGOm ） was 10.326 s/cm, which was consistent with the theoretical prediction. Therefore, it was confirmed that the Box-Behnken re- sponse surface design is an efficient method to optimizethe preparation conditions for graphene.