Cellulose nanomaterials have been widely investigated in the last decade, unveiling at- tractive properties for emerging applications. The ability of sulfated cellulose nanocrystals (CNCs) to guide the supramolecular organization of amphiphilic fullerene derivatives at the air/water in- terface has been recently highlighted. Here, we further investigated the assembly of Langmuir hy- brid films that are based on the electrostatic interaction between cationic fulleropyrrolidines depos- ited at the air/water interface and anionic CNCs dispersed in the subphase, assessing the influence of additional negatively charged species that are dissolved in the water phase. By means of isotherm acquisition and spectroscopic measurements, we demonstrated that a tetra-sulfonated porphyrin, which was introduced in the subphase as anionic competitor, strongly inhibited the binding of CNCs to the floating fullerene layer. Nevertheless, despite the strong inhibition by anionic mole- cules, the mutual interaction between fulleropyrrolidines at the interface and the CNCs led to the assembly of robust hybrid films, which could be efficiently transferred onto solid substrates. Inter- estingly, ITO-electrodes that were modified with five-layer hybrid films exhibited enhanced electri- cal capacitance and produced anodic photocurrents at 0.4 V vs Ag/AgCl, whose intensity (230 nA/cm2) proved to be four times higher than the one that was observed with the sole fullerene de- rivative (60 nA/cm2).