For the first time, the surface modification of nanophotocatalyst TiO2(P25)‐ZnO was reported by the introduction of Fe3+ for modulation of the photocatalytic activity. The nanophotocatalyst TiO2(P25)‐ZnO/Fe3+ was synthesized and its crystal structure, morphology, and photocatalytic activity were well determined by, diffuse reflectance spectroscopy, energy dispersive X‐ray, X‐ray diffraction, and scanning electron microscope analyses. The photocatalyst was applied for the selective oxidation of different aryl alcohols to the respective aldehyde beneath visible light (blue LED lamp, λ > 420 nm) in the presence of nitrate ion as oxidant. Also, for the first time, the effect of presence of an external magnetic field (5,000 G) contemporary with photoreaction was studied simultaneously by applying an external magnet field of 5,000 G and valuable results were obtained so that the time of photoreaction declined considerably up to 65%. This study has many advantages like the use of a magnetic field as a green technology, being clean, and zero energy. Also, the photoreaction did stop at the stage of aldehyde to provide a considerable selectivity.