The technique of facile co-precipitation was employed to prepare the pure ZnO and Gd doped ZnO photocatalysts. The physio-chemical properties of the prepared samples were analysed through various analytical techniques. The X-ray diffraction analysis clearly shows that higher amount of Gd dopant creates the secondary phase in addition to normal peaks of ZnO crystals. The visible light absorption increases with increasing the Gd amount in ZnO which is evident from UV–Vis DRS analysis. The as synthesized 3% Gd doped ZnO exhibits the highest photocatalytic activity on Methylene blue dye degradation under visible light irradiation compared to other photocatalysts. The enhanced degradation activity of the photocatalyst demonstrates the improved visible light absorption of the materials due to the incorporation of Gd ions into the ZnO lattice. The possible reaction mechanism and degradation pathway of the photocatalyst has been discussed in detail and the stability of the catalyst have been confirmed by recycle process. Display omitted •Facile co-precipitation method was used to prepare the pure and Gd doped ZnO photocatalyst.•The visible light absorption increases with increasing the percentage of Gd.•The Methylene blue dye degradation efficiency reaches 93% under visible light irradiation over 3% Gd doped ZnO.