This paper presents a facile single step strategy for fabrication of tungsten, bismuth and vanadium mixed metal oxide nanoarrays. WO3-BiVO4 heteronanostructure was obtained hydrothermally with reaction time of two hrs at low temperature 110 degrees C. The morphology of as prepared WO3-BiVO4 heterostructure revealed uniform and prominent nanorods like architectures under FE-SEM. These heteronanostructures were of variable sizes i.e., width <= 100 nm and length 200-400 nm respectively. The energy dispersive X-ray analysis (EDX) and elemental mapping of heteronanostructure further confirmed W, Bi, V and O entities in good elemental composition. The purity and crystalline nature of as synthesized WO3-BiVO4 were confirmed from X-ray crystallographic (XRD) analysis. UV-Visible spectroscopy and Raman analysis were also carried out to investigate optical properties of WO3-BiVO4. The band gap energy of WO3-BiVO4 calculated from UV-Visible absorption and diffused reflectance spectroscopy's was observed to be 2.1 eV respectively. The photoelectrochemical (PEC) studies of Fro coated WO3-BiVO4 showed a stable and repeatable photocurrent response under 1 SUN solar irradiation source. The linear sweep voltammetry (LSV) and Cyclic Voltammetry (CV) also corroborated substantial photocurrents at different oxidation and reduction potentials. Consequently, it is envisioned that this one-step strategy for in-situ fabrication of WO3-BiVO4 heteronanostructures have potential applications in solar-driven photoelectrochemical water splitting reactions. (C) 2017 Elsevier Ltd. All rights reserved.