Gao Lianlian, Zhang Zhigang, Zhao Jinping, Zhou Jin, Miao Zhichao, Si Weijiang, Zhuo Shuping
School of Chemistry and Chemical Engineering, Shandong University of Technology Zibo 255049 P. R. China
RSC Adv. 2018 May 24;8(34):19164-19170. doi: 10.1039/c8ra02231c. eCollection 2018 May 22.
A graphene scroll (GSC) is a new type of graphene-derivative material, that has widely attracted attention. However, the controllable preparation of GSCs is a major factor influencing their development and application. In this work, sodium citrate (SC) was added to a graphene oxide (GO) aqueous suspension and GSCs were controllably prepared on a large-scale by a cold quenching method. The results show that the number of scroll layers and the curling degree of the GSCs could be controlled by the quantity of SC added. The diameter of the GSCs increased when SC was added. Compared to the GSC without SC (265 nm), the average diameter of GSC(SC-40) (obtained by adding 40 mg SC to 100 mL GO solution (1 mg mL)) is 491 nm. When excessive SC was added, such as 100 mg, the average diameter reached 679 nm. Moreover, these GSCs were used as a supercapacitor electrode material and the electrochemical performance was tested. The specific capacitance of GSC(SC-40) (178 F g) is higher than that of the GSC without SC (107 F g) at the same current density of 1.0 A g. However, when a larger quantity of SC was added, the specific capacitance of the GSCs decreased. So, the number of scroll layers and the curling degree of the GSCs have a significant effect on the electrochemical properties of the supercapacitor.
石墨烯卷（GSC）是一种新型的石墨烯衍生材料，已广泛引起关注。然而，GSC的可控制备是影响其发展和应用的主要因素。在这项工作中，将柠檬酸钠（SC）添加到氧化石墨烯（GO）水悬浮液中，并通过冷淬法大规模可控地制备了GSC。结果表明，GSC的卷曲层数和卷曲程度可以通过添加SC的量来控制。添加SC时，GSC的直径会增加。与未添加SC的GSC（265 nm）相比，GSC(SC - 40)（通过向100 mL GO溶液（1 mg/mL）中添加40 mg SC获得）的平均直径为491 nm。当添加过量的SC（如100 mg）时，平均直径达到679 nm。此外，这些GSC被用作超级电容器电极材料并测试了其电化学性能。在相同电流密度1.0 A/g下，GSC(SC - 40)（178 F/g）的比电容高于未添加SC的GSC（107 F/g）。然而，当添加更大量的SC时，GSC的比电容会降低。因此，GSC的卷曲层数和卷曲程度对超级电容器的电化学性能有显著影响。
