Thiol-functionalized carbon dot-enabled self-catalytic reduction-dynamic assembly for constructing three-dimensional porous reduced graphene oxide aerogels toward high-performance terahertz modulation

Abstract

Three-dimensional (3D) porous reduced graphene oxide (rGO) aerogels are promising for broadband terahertz (THz) modulation due to their low density, high porosity, and tunable conductivity. However, conventional methods for reducing graphene oxide often cause graphene layer agglomeration and stacking, limiting its THz applications. Here, a novel method for fabricating lightweight porous rGO aerogels is proposed based on a thiol-functionalized carbon dot (SH–CD)-enabled “self-catalytic reduction-dynamic assembly” strategy. As a dual-functional agent, SH–CDs enable efficient in situ reduction and controlled crosslinking of GO sheets under mild reaction conditions, thereby facilitating the construction of aerogels featuring high electrical conductivity, a fully developed 3D interconnected porous network, and abundant interfacial domains. This well-designed structure effectively suppresses excessive densification of the graphene layer while enhancing the internal reflection and scattering of THz waves at multiple interfacial domains. Consequently, the rGO aerogels exhibit outstanding THz shielding and absorption, achieving a maximum reflection loss of −37 dB and a shielding effectiveness of −44 dB, with average values of −26 and −37 dB, respectively—exceeding those of most reported materials. THz transmission and reflection imaging further confirm the material's potential for electromagnetic stealth, shielding, and related applications.