Selective Cleaning of Hollow Nanoporous Carbon Cubes for Electromagnetic Wave Absorption

This study introduces a method for fabricating hollow nanoporous carbon cubes (HPCCs), utilizing the selective purification effect of acetone on a small-molecule phenolic resin (PR)/NaCl precursor. The impact of acetone-induced purification on the nanoscale microstructure and electromagnetic wave-absorbing properties of HPCCs is systematically explored. Using a template-etch-carbonization process, the HPCCs exhibit a significant increase in specific surface area from 149.61 m2/g (HPCCs0min) to 315.86 m2/g (HPCCs10min), highlighting the nanoscale structural modifications induced by acetone treatment. At 5 wt % absorber content and a 2.7 mm thickness, HPCCs treated for 10 min demonstrate optimal wave-absorbing performance, achieving a peak reflection loss (RLmin) of −24.1 dB and an effective absorption bandwidth (EAB) of 7.3 GHz. These results underscore the critical role of nanoscale surface area and pore volume modulation in enhancing the electromagnetic wave absorption capabilities of HPCCs.