文摘
Highly ordered hexagonal meso-structured, vesicles, and mesoporous ordered siliceous foams have been elaborately synthesized in weak HCl solution under static conditions without any organic additives by finely tuning reaction pH (3.0–5.0) and/or the amount of adding sodium sulfate (Na2SO4). Lower pH value is favorable for hexagonal structure and higher pH value and Na2SO4 concentration is beneficial for vesicles and foams. Siliceous materials with different morphologies (rod, vesicle and foam), structures (hexagonal, vesicle and foam) and pore sizes were used for volatile organic compounds (VOCs) removal. The adsorption and desorption performance of hexagonal mesostructure (S1), vesicles (S5) and macroporous ordered siliceous (S7) samples were investigated under static (water vapor, n-hexane and 93# gasoline) and dynamic (n-hexane) conditions. Compared with S1, S5, commercial silica gel (SG) and activated carbon (AC), S7 shows higher static adsorption capacity of n-hexane and 93# gasoline, more stable breakthrough time and larger n-hexane adsorption capacity under dynamic adsorption conditions. The designed siliceous materials with high VOCs removal capacity and recyclability show great potential for VOCs controlling.