Iron oxide nanoparticles (IONP) with different distinctive morphologies (spherical, cubic, flower-like and needles) were utilized for modification of screen-printed carbon electrodes (SPCE) to be used for synthetic organic dye degradation by an electrochemical approach. This platform was implemented for removal of the synthetic organic dye, Reactive Black 5 (RB5) in aqueous solution. Modified SPCE with spherically shaped IONP (IONS) had the highest dye removal efficiency. Thus, IONS were then used for surface decoration of the most common carbon-based materials (graphene, graphene oxide, carboxylated graphene, graphene nanoribbons, graphene nanoplatelets, single-and multi-wall carbon nanotubes), and the nanocomposites formed were deposited on the electrode surfaces. Using IONS/ graphene composite (IONS@GN) for electrode modification resulted in the best effect. Removal of RB5 with this electrode was 51% better in comparison with bare SPCE, reducing the time required for complete dye degradation from 61 to 30 min Using IONS-modified SPCE, total RB5 removal occurred in 51 min, improving the performance by 16% over that of bare SPCE. The effects determined, i.e., the best IONP morphology and best type of carbon-based material for nanocomposite formation to enhance RB5 removal will provide guidelines for further modifications of SPCE with nanomaterials and nanocomposites, for application of this electrochemical approach in the degradation of organic pollutants.