Xu Qiang, Yang Guangmin, Fan Xiaofeng, Zheng Weitao
Key Laboratory of Automobile Materials (Jilin University), Ministry of Education, and College of Materials Science and Engineering, Jilin University, Changchun 130012, China.
College of Prospecting and Surveying Engineering, Changchun Institute of Technology, Changchun 130032, China.
ACS Omega. 2019 Aug 2;4(8):13209-13217. doi: 10.1021/acsomega.9b01359. eCollection 2019 Aug 20.
We explore the stability, electronic properties, and quantum capacitance of doped/co-doped graphene with B, N, P, and S atoms based on first-principles methods. B, N, P, and S atoms are strongly bonded with graphene, and all of the relaxed systems exhibit metallic behavior. While graphene with high surface area can enhance the double-layer capacitance, its low quantum capacitance limits its application in supercapacitors. This is a direct result of the limited density of states near the Dirac point in pristine graphene. We find that the triple N and S doping with single vacancy exhibits a relatively stable structure and high quantum capacitance. It is proposed that they could be used as ideal electrode materials for symmetry supercapacitors. The advantages of some co-doped graphene systems have been demonstrated by calculating quantum capacitance. We find that the N/S and N/P co-doped graphene with single vacancy is suitable for asymmetric supercapacitors. The enhanced quantum capacitance contributes to the formation of localized states near the Dirac point and/or Fermi-level shifts by introducing the dopant and vacancy complex.
我们基于第一性原理方法研究了掺杂/共掺杂硼（B）、氮（N）、磷（P）和硫（S）原子的石墨烯的稳定性、电子性质和量子电容。B、N、P和S原子与石墨烯形成强键合，所有弛豫后的体系均表现出金属行为。虽然具有高表面积的石墨烯可以增强双层电容，但其低量子电容限制了其在超级电容器中的应用。这是原始石墨烯中狄拉克点附近态密度有限的直接结果。我们发现，具有单空位的三重氮和硫掺杂表现出相对稳定的结构和高量子电容。有人提出它们可以用作对称超级电容器的理想电极材料。通过计算量子电容证明了一些共掺杂石墨烯体系的优势。我们发现，具有单空位的氮/硫和氮/磷共掺杂石墨烯适用于非对称超级电容器。增强的量子电容通过引入掺杂剂和空位复合体有助于在狄拉克点附近形成局域态和/或费米能级移动。
