Search

This paper proposes a simple and rapid microwave-assisted phosphorus-oxygen doped porous carbon (P/O-PC) preparation strategy is proposed using potassium citrate, Phytic acid (PA), and ethanol under air atmosphere. PA can be used as both a phosphorus source and a microwave absorbing agent. The P/O-PC500–0.75 has a large specific surface area of 905 cm2/g. P/O doping introduces defects into the carbon structure, which enhances the capacitance of the porous carbon. The P/O-PC500–0.75 demonstrates excellent capacitance values of 330 F/g and 389.4 F/g in 6.0 M KOH and 1.0 M H 2 SO 4 , respectively (1 A/g). In addition, the symmetrical supercapacitors assembled with the P/O-PC500–0.75 exhibit good electrochemical stability over 5000 cycles at 5 A/g, with a capacitance loss of only 3.6%. This microwave-assisted strategy offers simplicity in operation and low energy consumption, providing a new and efficient pathway to prepare carbon materials in a fast and simple manner. [Display omitted] [ABSTRACT FROM AUTHOR]

Complex service conditions often cause corrosion, rendering most microwave absorbers ineffective. Consequently, the development of bifunctional materials with exceptional properties in terms of both anti-corrosion and microwave absorption is of utmost importance. In this study, vanadium nitride nanofiber @ N-doped carbon (VN-F@NC) composite material with excellent microwave absorption and anti-corrosion was synthesized by combining V 2 O 5 precursor fibers encapsulated in polydopamine with ammonia reduction nitriding process. The amorphous N-doped carbon nanolayer, residual O element, and porous structure of VN-F@NC contribute to impedance matching, interfacial polarization, as well as multiple reflections and scattering. As a result, VN-F@NC exhibits strong microwave absorption ability in multiple bands, with optimal reflection loss of − 40.0 dB, − 63.6 dB, and − 52.5 dB in the C, X, and Ku bands, respectively. Moreover, the encapsulation of VN nanofibers with the N-doped carbon nanolayers protects them from corrosion, thereby increasing the polarization resistance to 3.61 × 105 Ω·cm2 and reducing corrosion current to 9.00 × 10-8 A/cm2. Therefore, the encapsulation of vanadium nitride fibers with N-doped carbon nanolayer emerges as a viable approach in enhancing the microwave absorption capabilities as well as the resistance against corrosion of absorbers. [Display omitted] [ABSTRACT FROM AUTHOR]