Molybdenum oxide nanostructured thin films were grown on fluorine doped tin oxide(FTO), indium doped tin oxide(ITO) and ordinary glass substrates by thermal evaporation process without vacuum and catalysts using molybdenum trioxide(MoO_3) powder as a source material and oxygen as a carrier gas.Various morphologies including nanobelts, disks and hexagonal rod-like nanostructures were obtained by changing the source and substrate temperatures during the growth of MoO_3 thin films. Structural parameters, morphology, composition and surface features of the films were characterized by XRD, SEM, EDAX,XPS, AFM and Raman spectroscopy. The films were orthorhombic in structure with preferred orientation along(0 1 0) plane. Morphology analysis reveals randomly aligned nanobelts with 40 nm in thickness and a width of 800 nm and 3–12 mm in length. The disks have 1.5 μm diameters, 1 μm thickness and hexagonal rod-like nanostructures with a length, breath and width of 2 μm, 1 μm and 100 nm are formed. The samples were investigated under dark and photocurrent conditions in H_2SO_4 aqueous solution as a function of applied potential. The photocurrent density of samples prepared on ITO and FTO substrate samples were compared and the results are discussed. Molybdenum oxide nanostructured thin films were grown on fluorine doped tin oxide (FTO), indium doped tin oxide (ITO) and ordinary glass substrates by vacuum evaporation process without vacuum and catalysts using molybdenum trioxide (MoO 3) powder as a source material and oxygen as a Structural gas, morphology, composition and surface features of the films were characterized by XRD, SEM , EDAX, XPS, AFM and Raman spectroscopy. The films were orthorhombic in structure with preferred orientation along (0 1 0) plane. Morphology analysis reveals randomly aligned nanobelts with 40 nm in thickness and a width of 800 nm and 3-12 mm in length. The disks have 1.5 μm diameters, 1 μm thickness and hexagonal rod-like nanostructures with a length, breath and width of 2 μm, 1 μm and 100 nm are The samples were investigated under dark and photocurrent conditions in H 2 SO 4 aqueous solution as a function of applied potential. The photocurrent density of samples prepared on ITO and FTO substrate samples were compared and the results were discussed.