Structural Evolution of Phosphorus Species on Graphene with a Stabilized Electrochemical Interface

Abstract

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 2 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 H 3 PO 4 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 3 −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.

Microporous Carbon Nanofibers Derived from Poly(acrylonitrile‐co‐acrylic acid) for High‐Performance Supercapacitors

“…The plots of the frequency dependence of the total capacitance, real capacitance C′ and imaginary capacitance C′′ are shown in Figure S9 d–f of the Supporting Information. Similar to the results of the GCD curve, ACNF‐12 has higher specific capacitance than ACNF‐6 and ACNF‐18 . The relationship between the total impedance and frequency for the ACNFs is shown in Figure 4 g. The total impedance of ACNF‐12 is lower than those of ACNF‐6 and ACNF‐18.…”

“…Similart ot he results of the GCD curve, ACNF-12 has highers pecific capacitance than ACNF-6 and ACNF-18. [49] The relationship between the total impedance and frequency for the ACNFs is shown in Figure 4g .T he total impedance of ACNF-12i sl ower than those of ACNF-6 and ACNF-18. This indicates that ACNF-12 has al ow internal resistance.…”

Phosphorous‐Doped Graphite Layers with Outstanding Electrocatalytic Activities for the Oxygen and Hydrogen Evolution Reactions in Water Electrolysis

“…Three major peaks split from high-resolution P2p peaks at 132.3, 133.1, and 134.0 eV were accordingly attributed to the C 3 −PO, C−P−O, and C−O−P groups (Figure 2b). [25,26] Whereas, the C−P species at about 130.2 eV unexpectedly absented from these five prepared samples. For three P species contents, from Table 1, it could be found that the C−O−P contents in five samples first increased and then decreased with the increase of heating temperature while the contents of C 3 −PO and C−P−O groups kept decreasing, indicating that the C−O−P group is more stable than the other two P moieties.…”

Integrating Effect of Surface Modification of Microporous Carbon by Phosphorus/Oxygen as well as the Redox Additive of p‐Aminophenol for High‐Performance Supercapacitors

“…[ 1–4 ] Carbon materials have shown tremendous potential and advantages in the field of SCs due to the excellent surface chemical property, good conductivity, adjustable pore structure, and high specific surface area. [ 5–11 ] Generally, the processes for synthesizing carbon materials include freeze‐drying, [ 12 ] acid pickling, [ 13 ] template method, [ 14 ] or organic reaction, [ 15 ] which are complex and time‐consuming tasks. On the other hand, surface modification is proved to improve the electrochemical performance of electrode materials efficiently.…”

“…Moreover, P is larger and stronger than N due to atomic radius and electron donor capacity. [ 11 ] More importantly, P as an oxidation protective agent can be helpful to improve the cyclic stability, capacity retention, and working voltage window of capacitors. [ 18 ] In addition, O‐doped microporous carbon has been proved to improve the hydrophilicity of the surface to aqueous electrolytes, which can facilitate the redox reaction and ensure excellent rate performance.…”