TiN nanoparticles anchored on porous carbon black: The synergistic effect of porosity, surface roughness and surface plasmon on high-performance broadband infrared absorption

Porous carbon black loaded with TiN nanoparticles was developed as a broadband infrared (IR) absorber. The unique porous structure, characterized by variable pore sizes and random spatial distribution, effectively guides and absorbs electromagnetic waves across a broad wavelength range. The incorporation of TiN nanoparticles enhance the surface roughness, facilitating multiple reflection and scattering, thereby extending the light propagation path. This modification notably addresses the absorption deficiencies in the 3.5–6 μm wavelength range, significantly improving overall absorption efficiency. IR absorption tests revealed that the original film achieved an average absorption rate of approximately 93.7 % within the 2.5–20 μm range, while the addition of TiN nanoparticles increased the absorption rate to 95.73 %. Finite-difference time-domain simulations results demonstrated a significant increase in electric field intensity around the carbon surface and TiN nanoparticles at 5 μm, attributed to the radiative absorption properties of carbon and the surface plasmon characteristics of TiN at shorter wavelengths. This absorber layer shows high potential for IR sensor applications.