Adsorption of asphaltenes from heavy oil onto in situ prepared NiO nanoparticles

► Asphaltenes adsorption onto in situ prepared nanoparticles from heavy oil matrix. ► Very high uptake in the order of 2.8 g/g nanoparticle. ► Formation of NiO nanoparticles with average diameter of 12 ± 5 nm. ► Multilayer adsorption from heavy oil reported. ► Comparison between the uptake of commercial and in situ prepared NiO particles.