The utilization of ambient low-pressure CO2 adsorption for carbon neutrality initiatives holds great potential.However, conventional liquid amine absorption methods for CO2 capture are plagued by high energy consumption and equipment corrosion issues.In this study, we present a novel approach using industrial waste silica fume (SF) as a precursor and tetraethylenepentamine (TEPA) as a chem. modifying agent to efficiently synthesize low-cost mesoporous solid amine adsorbents within the waste-derived mesoporous powder sorbents (MPS) series.Employing the static adsorption technique, the impact of both adsorption temperature and amine loading on the CO2 adsorption efficacy was comprehensively investigated.The optimized sample, MPS-TEPA-30, demonstrated a superior CO2 adsorption capacity, achieving 2.22 mmol g-1 at 323 K and 1 bar, a significant 6.8-fold increase compared to the unmodified MPS material (0.326 mmol g-1).Addnl., MPS-TEPA-30 demonstrated notable performance advantages, surpassing SBA15-TEPA-30 and MCM41-TEPA-30 with near 1.49- and 2.12-fold increases in adsorption capacity, resp.Impressively, MPS-TEPA-30 exhibited remarkable adsorption ability beyond 1.5 mmol g-1 at ultralow pressures (<0.01 bar), suggesting its potential for ambient ultralow-pressure CO2 capture.Moreover, MPS-TEPA-30 showed exceptional stability over multiple adsorption-desorption cycles, with only a marginal 6 % decrease in CO2 capture efficiency after the seventh cycle.Thermogravimetric anal. confirmed the robust thermal stability of the amine-functionalized adsorbent (∼473 K), rendering it suitable for high-temperature adsorption-desorption processes.The Ideal Adsorbed Solution Theory (IAST) equation predicted an excellent adsorption selectivity of 1600 for the CO2/N2 (1:1) mixture at 323 K and 10 mbar, underscoring the promising prospects of MPS-TEPA-30 in CO2 capture and selective separation applications from ambient condition.