CAS Key Laboratory of Carbon Materials, Institute of Coal Chemistry , Chinese Academy of Sciences , Taiyuan 030001 , China.
University of Chinese Academy of Sciences , Beijing 100049 , P. R. China.
ACS Appl Mater Interfaces. 2019 Mar 27;11(12):11421-11430. doi: 10.1021/acsami.8b21903. Epub 2019 Mar 13.
Phosphorus doping is an effective approach to tailor the surface chemistry of carbon materials. In this work, two-dimensional graphene, as a simplified model for all sp hybrid carbon allotropes, is employed to explore the surface chemistry of P-doped carbon materials. Thermally reduced graphene oxide, with abundant residual oxygen functionalities, is doped by phosphorus heteroatoms through HPO activation, followed by passivation in an inert atmosphere. The structural evolution of the phosphorus species in the carbon lattice during the thermal treatment is systematically studied by Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, X-ray diffraction, and Raman spectroscopy with the assistance of first-principles calculations. The C-P═O configuration is identified as the most stable structure in the graphene lattice and plays a key role in stabilizing the electrochemical interface between the electrode and electrolyte. These features enable an electrode based on P-doped graphene to exhibit an enlarged potential window of 1.5 V in an aqueous electrolyte, a remarkable improved cycling stability, and an ultralow leak current. Therefore, this contribution provides insights for designing phosphorus-doped carbon materials toward electrocatalysis, energy-related applications, and so forth.
磷掺杂是一种有效的方法，可以调整碳材料的表面化学性质。在这项工作中，二维石墨烯作为所有 sp 杂化碳同素异形体的简化模型，被用于探索磷掺杂碳材料的表面化学性质。通过 HPO 活化，将富含残余含氧官能团的热还原氧化石墨烯掺杂磷杂原子，然后在惰性气氛中进行钝化。通过傅里叶变换红外光谱、X 射线光电子能谱、X 射线衍射和拉曼光谱，并结合第一性原理计算，系统研究了磷物种在热解过程中在碳晶格中的结构演变。在石墨烯晶格中，C-P═O 构型被确定为最稳定的结构，在稳定电极与电解质之间的电化学界面方面发挥了关键作用。这些特性使基于磷掺杂石墨烯的电极在水溶液电解质中具有 1.5 V 的扩大电位窗口、显著提高的循环稳定性和超低漏电电流。因此，本研究为设计用于电催化、能源相关应用等领域的磷掺杂碳材料提供了新的思路。
