纤维素基硼氮共掺杂碳点的制备及其改善铜硫化物电化学性能的研究

Preparation of Boron and Nitrogen Co-doped Cellulose-based Carbon Dots and Their Improvement of Electrochemical Properties of Copper Sulfides

关键词:  纤维素  碳点  铜硫化物  超级电容器

Key Words:cellulose  carbon dots  copper sulfides  supercapacitors

摘要:以氧化纤维素（OC）为碳源，硼酸和氨水为掺杂剂，采用一步水热法制备了硼氮共掺杂纤维素基碳点（B-N-CDs），然后采用低温浸渍法构筑了CuS/B-N-CDs复合材料，并对B-N-CDs的光学性能及复合材料的电化学性能进行了系统表征。结果表明，B-N-CDs的最佳激发波长、发射波长分别为337、420 nm，平均粒径为1.79 nm。CuS/B-N-CDs复合材料在1 A/g电流密度下的比电容为896.0 F/g，由其组装的非对称超级电容器CuS/B-N-CDs//AC ASC在功率密度806.5 W/kg条件下，能量密度达60.7 Wh/kg，并且在1~10 A/g的电流密度范围内，具有良好的倍率性能（库伦效率93.9%）；此外，在经过10 000次充放电后，电容保持率为96.2%，循环性能良好。

Abstract:The boron and nitrogen co-doped cellulose-based carbon dots （B-N-CDs） were prepared by a one-step hydrothermal method using oxidized cellulose （OC） as the carbon source， boric acid and ammonia as the dopants， and then composite materials CuS/B-N-CDs were constructed by the method of low-temperature impregnation. The optical properties of the B-N-CDs and the electrochemical properties of the composite materials were systematically characterized. The results showed that the optimal excitation and emission wavelengths of B-N-CDs were 337 and 420 nm， respectively， and the average particle size was 1.79 nm. The specific capacitance of composite materials CuS/B-N-CDs at 1 A/g current density was 896.0 F/g. The asymmetric supercapacitor CuS/B-N-CDs//AC ASC assembled therefrom achieved an energy density of 60.7 Wh/kg at power density of 806.5 W/kg and it had good multiplicative performance （coulomb efficiency of 93.9%） in the current density range of 1~10 A/g. In addition， the capacitance retention rate of supercapacitor was 96.2% after 10 000 times of charging and discharging， with good cycling performance.