Constructing Ni₁₂P₅/Ni₂P Heterostructures to Boost Interfacial Polarization for Enhanced Microwave Absorption Performance

Abstract

Heterostructures with a rich phase boundary are attractive for surface-mediated microwave absorption (MA) materials. However, understanding the MA mechanisms behind the heterogeneous interface remains a challenge. Herein, a phosphine (PH3) vapor-assisted phase and structure engineering strategy was proposed to construct three-dimensional (3D) porous Ni12P5/Ni2P heterostructures as microwave absorbers and explore the role of the heterointerface in MA performance. The results indicated that the heterogeneous interface between Ni12P5 and Ni2P not only creates sufficient lattice defects for inducing dipolar polarization but also triggers uneven spatial charge distribution for enhancing interface polarization. Furthermore, the porous structure and proper component could provide an abundant heterogeneous interface to strengthen the above polarization relaxation process, thereby greatly optimizing the electromagnetic parameters and improving the MA performance. Profited by 3D porous heterostructure design, P400 could achieve the maximum reflection loss of −50.06 dB and an absorption bandwidth of 3.30 GHz with an ultrathin thickness of 1.20 mm. Furthermore, simulation results confirmed its superior ability (14.97 dB m2 at 90°) to reduce the radar cross section in practical applications. This finding may shed light on the understanding and design of advanced heterogeneous MA materials.

Sequential Phase Conversion‐Induced Phosphides Heteronanorod Arrays for Superior Hydrogen Evolution Performance to Pt in Wide pH Media

“…[ 13 ] Herein, we deliberately compared our Ni 2 P‐Ni 12 P 5 @Ni 3 S 2 /NF with another reference samples prepared by tuning the sodium hypophosphite amount, which exhibited different content ratios of Ni 2 P and Ni 12 P 5 , and accordingly changeable interface length (amount) (details in Experimental Section, Figure S42, and Table S1, Supporting Information). [ 68 ] Interestingly, our targeted sample Ni 2 P‐Ni 12 P 5 @Ni 3 S 2 /NF (prepared with moderate 0.25 g of sodium hypophosphite) exhibited the best activity in all electrolytes, which could be due to the optimum balance between the interfacial coupling and surface morphology (details in Figures S43 and S44, Supporting Information).…”

Ni Flower/MXene-Melamine Foam Derived 3D Magnetic/Conductive Networks for Ultra-Efficient Microwave Absorption and Infrared Stealth

“…EM absorption performance could be intuitively evaluated by reflection loss (RL), and the RL was calculated according to the transmission line theory as: where Z in is the normalized input impedance of the absorber, Z 0 is the impedance of free space, f is the frequency of the EM wave, d is the thickness of the absorber, and c is the velocity of light in free space [ 9 , 47 ]. Specifically, the RL value should be lower than -10 dB, and more than 90% of the incident EM waves will be attenuated [ 48 ].…”

Enhanced Microwave Absorbing Ability of Carbon Fibers with Embedded FeCo/CoFe2O4 Nanoparticles

“…Therefore, it is significant to study the RCS of the material coating corresponding to different incident angles of EM waves. 45 As shown in Figure 7, the HFSS technology is employed to simulate RCS values of the MF composite coatings under different incident angles. As shown in Figure 7a, the RCS values of PEC and MF-9 are basically coincidental and are larger than other composite coatings, indicating that MF-6, MF-7, and MF-8 coatings have great contribution on EM wave attenuations.…”

“…However, in practical application scenarios, especially aircrafts, it is necessary to face EM waves with different incident angles. Therefore, it is significant to study the RCS of the material coating corresponding to different incident angles of EM waves . As shown in Figure , the HFSS technology is employed to simulate RCS values of the MF composite coatings under different incident angles.…”