Dimension and morphology of photocatalysts has extensive interest in order to use the effective concurrence of photon. Despite TiO2 and ZnO, WO3 has also been considered as a promising candidate in terms of remediation and purification that owes to its visible light absorption and non-toxic environmental friendliness. In this study, we report the preparation of nanostructured WO3 with different morphologies for the photocatalytic degradation of organic pollutants without the presence of any sacrificial agents. The study envisages the effect of the aspect ratio of WO3 particles on the photochemical process and their inherent reactive species mechanism. Mechanistic reasoning revealed that, apart from the hole and hydroxyl radicals as the participating species in both structures, a significant contribution from superoxide radicals takes place in the presence of nanorods and promotes the photochemical reaction. High aspect ratio facilitates the absorption coefficient and resultant efficiency. Both the catalysts retain its reactivity after regeneration and confirms the consistent catalytic reusability. Reactivity enhancement of any photocatalyst is possible through tuning the inherent structure of the material. © 2018 The Society of Powder Technology Japan