A novel anhydrous colloidal suspension was synthesized experimentally for CO2 absorption by dispersing hollow silica nanospheres (HSNs) modified by diethylenetriamine (DETA) in 2-[2-(dimethylamine) ethoxy] ethanol (DMEE) in this work. The physicochemical properties of HSNs synthesized were studied, and HSNs presented uniformed sphere-like morphology and microporous structures dominated by micropores. The CO2 absorption performance of DETA-HSNs/DMEE with different DETA loading contents (0 - 60 wt%) was investigated. A high DETA loading content can promote effectively the CO2 absorption capacity, and 60 wt%DETA-HSNs/DMEE had a highest absorption capacity of 1.0630 ± 0.0849 mmol/g. But more DETA resulted into a greater resistance of CO2 transfer in the late stage of absorption, and extend the absorption time. Moreover, pseudo-second-order model could be more successful to predict the CO2 absorption process in the colloidal suspensions studied.