Conventional powdered porous carbon materials face serious challenges, such as difficult recycling, easy clogging, and potential secondary pollution, and thus are not ideal for practical engineering applications. Endeavoring to address these issues, a fortuitous revelation emerged: the deliberate modulation of experimental parameters yields macroscopic materials of heightened stability, affording the distinct advantage of facile separation and recyclability. This investigative pursuit employed sodium alginate (SA) as the carbon precursor, K2CO3 as the activating agent, and ammonium polyphosphate (APP) as an N/P co-doping agent. Through a meticulously executed one-step pyrolysis process, macroscopic materials rooted in N/P co-doped sodium alginate (C/N/P-0.3) were skillfully synthesized. Comprehensive SEM and BET analyses elucidate that N/P co-doping amplifies the genesis of defects and active sites during activation, surpassing the impact of K2CO3 in isolation. This strategic co-doping approach results in a notable 1.30-fold augmentation in specific surface area and a concurrent 1.34-fold expansion in the total pore volume of the material, thereby culminating in a substantial 25.39% elevation in the adsorption of dimethyl phthalate (DMP). Furthermore, corroborative assessments utilizing XPS, FTIR, and allied methodologies substantiate that the synergistic interplay under specific experimental conditions fortifies the stability of their layered structure, concurrently enhancing material mechanical properties by an appreciable 59.8%. Notably, the exceptional regenerative performance of C/N/P-0.3 was validated through four experimental cycles. This study posits that these innovative porous carbon materials, predicated upon their copious internal pore architecture and steadfast macroscopic morphology, harbor substantial promise for multifarious engineering applications.