This study reports on the highly simple fabrication of green carbon black (GCB) generated from scrap tires with acetic acid to improve the adsorption efficiency for water purification, which is thoroughly compared with conventional carbon black (CB) obtained from petrochemicals. Unlike traditional modification processes with strong acids or bases, the introduction of a relatively mild acid readily allowed for the effective modification of GCB to increase the uptake capability of metal ions and toxic organic dyes to serve as effective adsorbents. The morphological features and thermal decomposition patterns were examined by electron microscopy and thermogravimetric analysis (TGA). The surface functional groups were characterized by Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS). The structural information (ratio of D-defects/G band-graphitic domains) obtained by Raman spectroscopy clearly suggested the successful fabrication of GCB (I_D/I_G ratio of 0.74), which was distinctively different from typical CB (I_D/I_G ratio of 0.91). In the modified GCB, the specific surface area (S_BET) gradually increased with the reduction of pore size as a function of acetic acid content (52.97 m²/g for CB, 86.64 m²/g for GCB, 102.10-119.50 m²/g for acid-treated GCB). The uptake capability of the modified GCB (312.5 mg/g) for metal ions and organic dyes was greater than that of the unmodified GCB (161.3 mg/g) and typical CB (181.8 mg/g), presumably due to the presence of adsorbed acid. Upon testing them as adsorbents in an aqueous solution, all these carbon materials followed the Langmuir isotherm over the Freundlich model. In addition, the removal rates of cationic species (>70% removal of Cu²⁺ and crystal violet in 30 min) were much faster and far greater than those of anionic metanil yellow (<40% removal in 3 h), given the strong electrostatic interactions. Thus, this work demonstrates the possibility of recycling waste tires in the powder form of GCB as a cost-effective and green adsorbent that can potentially substitute traditional CB, and the modification strategy provides a proof of concept for developing simple fabrication guidelines of other carbonaceous materials.

The accumulation of microplastics originating from single‐use personal protective equipment presents a growing environmental concern. Developing biodegradable fibrous alternatives is essential, but integrating robust antimicrobial efficacy with stable electrostatic capture while maintaining degradability remains a critical challenge. Here, we report a surface co‐functionalization strategy addressing these challenges through covalent immobilization of sodium copper chlorophyllin (SCC) and quaternary ammonium compounds (QAC). Beyond simple dual functionalization, this molecular design induces intramolecular charge separation, suppressing electron‐hole recombination in SCC and thereby amplifying reactive oxygen species generation under visible light. Simultaneously, QAC introduce permanent cationic surface charges that enable contact‐mediated microbial inactivation and humidity‐resistant electrostatic particle capture. Demonstrated on biodegradable silk nanofibers as a model substrate, the functionalized fibers exhibit potent antibacterial and antiviral activity under both dark and illuminated conditions, together with high nanoparticle capture efficiency. Importantly, the fibers retain intrinsic biodegradability, undergoing near‐complete degradation under enzymatic conditions and substantial decomposition in soil environments. This work establishes a versatile surface functionalization platform applicable to diverse fibrous substrates, offering a sustainable alternative to conventional microplastic‐generating protective materials.