组氨酸功能化碳点/石墨烯气凝胶的制备及超级电容器性能

通过一步水热法制备组氨酸功能化碳点/石墨烯气凝胶(His-CDs/GA)。该材料具有独特的三维多孔结构、丰富的含氮和含氧官能团, 有利于电解液离子的快速扩散和提供更多的活性位点。当GO与His-CDs的质量比为2 : 1时, His-CDs/GA-2在1 A·g ^-1电流密度下比电容达到304 F·g ^{- 1}, 比GA(172 F·g ^-1)提高了76.7%; 当电流密度从1 A·g ^-1增加到50 A·g ^-1, 其比电容保持率为71.4%; 在电流密度10 A·g ^-1下, 循环充放电30000次后, 比电容仍保留93.5%。由His-CDs/GA组装的对称超级电容器展现出高能量密度(在功率密度为250 W/kg时, 能量密度达到10.14 Wh/kg)和良好的循环性能(在5 A·g ^-1下循环充放电20000次后, 比电容保持率为88.4%)。结果表明, His-CDs/GA是一种应用前景广阔的超级电容器电极材料。

Synthesis and Supercapacitor Performance of Histidine-functionalized Carbon Dots/Graphene Aerogel

Histidine-functionalized carbon dot/graphene aerogel (His-CDs/GA) were synthesized via the one-step hydrothermal method. The as-prepared His-CDs/GA exhibits unique three-dimensional porous structure, rich nitrogen and oxygen-containing functional groups, which facilitate the rapid diffusion of electrolyte ions and provide more active sites. When the mass ratio of GO and His-CDs is 2 : 1, the specific capacitance of His-CDs/GA-2 reaches 304 F·g ^-1 at a current density of 1 A·g ^-1, which increases 76.7% compared with that of GA (172 F·g ^{- 1}). With the current density increasing from 1 A·g ^-1 to 50 A·g ^-1, the specific capacitance retention of His-CDs/GA-2 achieves 71.4%. The specific capacitance of His-CDs/GA-2 still remains 93.5% over 30000 cycles at 10 A·g ^-1. In addition, a symmetrical supercapacitor assembled by His-CDs/GA possesses a high energy density of 10.14 Wh/kg at a power density of 250 W/kg, and good cyclic performance with 88.4% capacitance retention at 5 A·g ^-1 over 20000 cycles. The results show that His-CDs/GA is a promising electrode material for supercapacitors.