Photoelectrochemical (PEC) cells for solar-energy conversion have received huge interest as a promising technology for renewable energy production. For the efficient application of such cells, it is necessary to develop adequate photoelectrodes. Recently, bismuth vanadate (BiVO4) has emerged as a promising photoanode due to its visible light harvesting properties, band edge positions and low-cost of synthesis. In this study, the effects of N5+ ion irradiation (75keV, 2 × 1014 and 4 × 1014 ions/cm2 ) on physicochemical properties of hydrothermally synthesized BiVO4 thin films were examined. From X-ray diffraction (XRD) study can be concluded that initial monoclinic material didn’t sustain any phase transition after irradiation. Also, preferential orientation remained dominantly along [010] direction with a slightly increasing share of [121] oriented growth, especially after irradiation with 2 × 1014 ions/cm2 . XRD measurements showed shift towards the higher 2θ after irradiation which indicates that interplanar distances decreases. The highest level of crystallinity was observed for the sample irradiated with fluence of 4 × 1014 ions/cm2 . Scanning electron microscopy (SEM) revealed prismatic morphology of all samples with an average grain size of 600 nm without visible traces of irradiation.Raman spectroscopy confirmed presence of bands that correspond to the monoclinic scheelite phase. X-ray photoelectron spectroscopy (XPS) analysis of V 2p confirmed presence of V5+ and V4+ while analysis of O 1s confirmed presence of oxygen in the form of lattice oxygen and in the form of hydroxide. UV-Vis Diffuse Reflectance spectroscopy revealed that calculated band gap decreases with the increase of fluence
