Construction of biomass-derived hierarchically porous carbon towards high-efficiency removal of dye pollutants and brilliant electromagnetic wave absorption.

Governing dye discharge and electromagnetic radiation is increasingly crucial for environmental protection and stealth-relevant systems. Nevertheless, integrating high-efficiency dye removal and brilliant electromagnetic wave (EMW) absorption within one material remains great challenging because of the different requirements for structure. In this regard, a novel biomass-derived porous carbon with tailored pore architectures was successfully constructed through a feasible strategy combining activation and carbonization. The resultant porous carbon reveals hierarchically porous structure composing micropores and mesopores, which benefits to capture dye molecules and EMW through the synergistic effect of various pores. The fabricated activated porous carbon-4 (APC-4) features a well-developed hierarchical porous structure with a high specific surface area of 1510.8 m2/g and a pore volume of 0.857 cm3/g. Experiments powerfully demonstrate the high-efficiency cationic dye adsorption and EMW absorption capabilities of the prepared porous carbon. The APC-4 realizes an apparent maximum cationic dye (methylene blue) adsorption capacity of 782.13 mg/g and an excellent removal efficiency of 99.9%. Moreover, the adsorption capability of APC-4 reveals outstanding environmental adaptability and recyclability. Additionally, the APC-4 obtains a brilliant RLmin of -58.36 dB at 11.35 GHz and a wide EABmax of 4.86 GHz (10.12-14.98 GHz) under the thin matching thickness. The EAB could cover nearly all of the measured frequency by easily tuning the matching thicknesses. The stealth application potential used in real condition of the obtained porous carbon is intuitively verified by radar cross section simulation. This work offers an innovative solution strategy for environmental pollution control by integrating dye adsorption and EMW absorption, paving a novel way for designing and constructing multifunctional biomass-derived porous carbon.