“…The difference between the base liquids will directly affect the absorption effect of CO 2 , and the reported base fluids are listed as follows: (1) water, deionized (DI) water; 16 and (2) amine solutions, MEA, 17 methyldiethanolamine (MDEA), 18 diethanoleamine (DEA), 19 piperazine (PZ), 20 4-diethylamino-2-butanol (DEAB), 21 2-amino-2-methyl-1-propanol (AMP), 22 triethylenetetramine (TETA), 23 and MEA−MDEA. 24 In addition to the above-mentioned classification according to the type of base fluid, this review also classifies nanoparticles dispersed in a base fluid: (1) non-metallic oxide, SiO 2 25 and graphene oxide (GO); 26 (2) carbon-based adsorbent, carbon nanotubes (CNTs) 27 and multi-walled carbon nanotubes (MWCNTs); 28 (3) metal oxides, alumina (Al 2 O 3 ), 29 zinc oxide (ZnO), 30 magnesium oxide (MgO), 31 and copper oxide (CuO); 32 and (4) magnetic metal oxide, iron oxide (Fe 3 O 4 ) and ferric oxide (Fe 2 O 3 ). 33 Except for the above four types of common nanoparticles, a hybrid nanoparticle (NOHM) has been discovered in recent years.…”