The photocatalytic effect of the powder particles resembling a flower consisting of Ni and nanorods of ZnO was studied for the degradation of methylene blue (MB) dye, an organic pollutant in water. Mechanical alloying of pure Ni and Zn powders followed by dealloying in high pH electrolyte was used for the synthesis of the photocatalyst. The effect of catalyst dose, concentration (ppm) of the MB and pH of the solution on the performance of catalyst and kinetics of photodegradation were analysed. The as-prepared catalyst was found to be re-useable multiple times without any secondary post treatment to the catalyst. © 2020 Elsevier B.V.