We report tunable-morphology oriented facile yet scalable route to synthesize 1D (nanorod) and 2D (nanobelt) MoO₃ nanostructures at gram scale using conventional as well as sonochemistry assisted sol-gel technique. The structural, morphological and optical properties of the samples can be befittingly altered by varying the synthesis protocol. The resultant orthorhombic MoO₃ nanomorphs demonstrated efficient and expeditious photocatalytic degradation of the pollutant dye, Methylene Blue (MB). We have observed that appreciable photocatalytic MB dye-degradation can be accomplished within 30 minutes with high rate constants of 0.0786 min-1 and 0.233 min-1 for rod and belt-like MoO₃-nanostructures, respectively. The pilot results indicate that the resultant MoO₃ nanomorphs can be potentially used as solar light driven industrial photocatalyst material with their intrinsic photostability.