氧化石墨烯的酸性还原及其超级电容性能

采用改进的Hummers法制备氧化石墨烯(GO)，在酸性条件(pH=5)下以180°C进行水热还原，通过调节水热反应时间来制备不同还原程度的还原氧化石墨烯(RGO)。研究了不同的水热反应时间对RGO结构及超级电容性能的影响。结果表明：控制水热反应时间可以制备出还原程度不同的RGO，在电化学测试中，随着水热反应时间的延长，RGO电极的比电容呈先上升后下降的趋势。当水热反应时间为6 h时，RGO电极表现出最佳的超级电容性能，其在1 A/g电流密度下比电容达到251 F/g，相对于GO电极提高了225%。经过500次充放电循环后，RGO-6电极比电容保持率达到92%，具有优异的循环稳定性。

Acid reduction of graphene oxide and performance of supercapacitor

Graphene oxide(GO) was prepared by improved Hummers method. Hydrothermal reduction was performed at 180℃ under acidic conditions (pH=5). Reduced graphene oxide (RGO) with different reduction degrees was prepared by adjusting hydrothermal reduction time. The effects of different hydrothermal reduction time on RGO structure and supercapacitive performance were studied. The results showed that RGO with different degree of reduction could be prepared by controlling the time of hydrothermal reduction. With the increase of hydrothermal reduction time, the specific capacitance of the RGO electrode increases at the beginning and then decreases through electrochemical testing. When the hydrothermal reduction time was 6 h, the RGO electrode showed the best supercapacitive performance, and its specific capacitance reached 251 F/g at 1 A/g current density, which was 225% higher than the GO electrode. After 500 charge and discharge cycles, the RGO-6 electrode has a specific capacitance retention rate of 92%, which has excellent cycle stability.