<p>Bismuth molybdate (Bi₂MoO₆), as one of bismuth-based semiconductors, has aroused great interest in photocatalysis due to its layered structure, tailored morphologies, appropriate band gap, visible-light absorption. Nevertheless, the performance of Bi₂MoO₆ significantly depends on the synthesis approaches that control the phase purity, crystallinity and photocatalytic activity. This work focuses on a detailed investigation about the effects of hydrothermal and solvothermal synthesis approaches on phase evolution, structural features and photocatalytic performance of Bi-based molybdates for the degradation of organic pollutants when subjected to visible light irradiation. The prepared phases were verified by X-ray powder diffraction (XRD) in which hydrothermal process produced α-Bi₂Mo₃O₁₂, whereas solvothermal process resulted in γ-Bi₂MoO₆. When compared with α-Bi₂Mo₃O₁₂, the performance of γ-Bi₂MoO₆ showed improved crystallinity, a medium bandgap (~ 2.3–2.8&#xa0;eV) and excellent photocatalytic activity with a &gt; 95% degradation of MB within 120&#xa0;min. The higher performance was ascribed to the enhanced charge separation, extended absorption and definite layered structure. The optimal performance of γ-Bi₂MoO₆ obtained from the solvothermal process demonstrated its potential in visible light-driven water treatment. Therefore, these results collectively reveal that effect of the synthesis process can determine the phase composition and photocatalytic efficiency towards organic pollutants.</p> Graphical Abstract <p></p>