介孔型氮硫双掺杂石墨烯的制备及其电化学性能研究

Preparation of Mesoporous N, S Co-doped Graphene and Its Electrochemical Properties

以氧化石墨烯为碳前驱体,分别采用二氧化硅和过硫酸铵为模板剂和氮硫源,通过煅烧热解及后续去模板工艺制备了介孔型氮硫双掺杂石墨烯(MNSG).采用扫描电子显微镜(SEM)和X射线衍射(XRD)等手段对材料的形貌、结构和组成进行分析;同时采用恒电流充放电和线性扫描等技术对材料的电容和氧还原性能进行测试.研究表明,相比于不加二氧化硅直接合成得到的氮硫双掺杂石墨烯, MNSG具有卷曲的薄片形貌,更大的比表面积和孔尺寸、更高的缺陷度和掺杂量.当其用作电容和氧还原电极材料时, MNSG表现出更优异的电容和氧还原性能.

In this work, mesoporous N, S co-doped graphene (MNSG) was successfully prepared via thermal annealing followed by template removal strategy using graphene oxide, silicon dioxide and ammonium persulfate as carbon precursor, hard template and N as well as S sources, respectively. Scanning electron microscope (SEM), X-ray diffraction (XRD) and other techniques were employed to investigate the morphology, structure and composition of the obtained carbon samples. Meanwhile, galvanostatic charge/discharge curve, linear sweep voltammetry and other methods were utilized to measure the capacitance and oxygen reduction reaction performance of carbon samples. The results showed that MNSG possessed crumpled thin nanosheets, larger specific surface area as well as pore size, higher structure defect degree and doping amounts when compared to N, S co-doped graphene synthesized by similar thermal annealing process without addition of silicon dioxide. When the obtained carbon samples were used as electrode materials for capacitor and oxygen reduction reaction, MNSG exhibited more superior electrochemical performance than the counterparts.