This work examined the liquid-side controlled mass transfer process in a rotating packed bed (RPB) equipped with a surface-modified nickel foam packing (SNP), which is a hydrophobic structured packing. The chemical absorption system CO₂–NaOH was used to determine the effective interfacial area (a) and the liquid-side mass transfer coefficient (k_L). The volumetric liquid-side mass transfer coefficient (k_La) was thus calculated. Effects of rotational speed, liquid flow rate, and gas flow rate on these mass transfer parameters were investigated. Experimental results show that the RPB with SNP possessed a higher a and k_L and thus showed better mass transfer performance in comparison to the RPB with the non-modified nickel foam packing (NNP). Moreover, the possible mechanism for the enhancement of mass transfer in the RPB with SNP was also explored by a flow visualization method.