Photoelectrochemical properties of p-nickel oxide (NiO) thin film deposited on fluorine-doped tin oxide (FTO) electrode, by combination of co-precipitation in aqueous media along with the dip-coating process, were investigated by cyclic voltammetry and chronoamperometry techniques in sodium sulfate (Na2SO4) electrolyte solution. The electrochemical characterization measurements have shown that the FTO/p-NiO electrode presents sensitivity to UV light, as observed by the increased photo-induced current, exposed to a more negative potential. The photoelectrochemical parameters obtained were photocurrent response time (∆t1), photocurrent decay time (∆t0), and photocurrent density stability (jph, jlight on − jlight off). Besides, this electrode shows excellent performance for methylene blue degradation under UV light irradiation condition, with estimated kobs value of 170 × 10−4 min−1, which is nine times higher than the dark condition and about three times higher than NiO powder catalyst. Results presented here allow concluding that the p-NiO thin film stands as an important electrode material with technological potential to be used directly in environmental preservation.