Polyethyleneimine functionalized graphene oxide/methyldiethanolamine nanofluid: preparation, characterization, and investigation of CO2 absorption

•Amine modified graphene oxide was introduced into MDEA solution to improve the absorption capacity of CO2 gas.•The absorption capacity was improved up to 15% for CO2 after addition of amine modified GO.•Higher temperatures decreased the absorption capacity.•Absorption capacity was prompted with increasing the partial pressure.