Microwave-assisted rapid metallization of carbon fiber surfaces

• A rapid CF metallization strategy is developed by combining TA-mediated silver seeding with microwave-assisted electroless plating only in 5 min. • The resulting CF@TA-Ag(L) represents an enhancement of approximately 670 times compared with the used pristine CFs. • CF@TA-Ag(L) maintains stable electrical performance after 200 consecutive bending cycles and 30 minutes of ultrasonic agitation. • CF@TA-Ag(L) exhibits excellent EMI SE of 75.2 dB and low-voltage electrothermal temperature of 59.2 °C under 1 V. The metallization of carbon fibers (CFs) has become a promising strategy to significantly enhance electrical conductivity, enabling advanced applications in electromagnetic interference (EMI) shielding and electrothermal systems. Nevertheless, conventional metallization techniques often suffer from insufficient interfacial adhesion, intricate processing steps, and unfavorable environmental implications. In this study, a rapid and environmentally benign approach is proposed, combining tannic acid (TA)-mediated surface functionalization with microwave-assisted reduction. TA modification (CF@TA) enables the chelation of silver ions onto the CF surface, which are subsequently reduced in situ to generate silver nanocrystals (CF@TA-Ag(N)). Microwave irradiation expedites reaction kinetics and promotes uniform deposition, resulting in a dense, continuous, and strongly adherent silver layer (CF@TA-Ag(L)) within only 5 minutes. The CF@TA-Ag(L) specimens exhibit an electrical conductivity of 17,480 S·m -1 , representing a 670-fold increase compared with pristine CFs. These fibers retain mechanical integrity after 200 bending cycles, 30 min of ultrasonication and 100 tape cycles. Moreover, a high EMI shielding effectiveness of 75.2 dB is achieved, accompanied by notable low-voltage electrothermal performance, reaching 59.2 °C at only 1 V. This facile fabrication route offers substantial potential for applications in electromagnetic protection and energy-efficient heating technologies.