A new Zn(II)-based 3D metal-organic framework (MOF) with composition [Zn(L)(4,4′-bipy)4∙2H2O]n (1), had been synthesized using 1,4-bis(3-carboxylbenzyl)piperazine acid (H2L) ligand and 4,4′-bipyridine (4,4′-bipy) as co-ligand under solvothermal condition. The X-ray structural analyses reveal that compound 1 exhibits a 3-fold interpenetrating 3D net with pcu topology. The photocatalytic property of 1 had been investigated to photo-degrade methyl violet (MV) an organic dye present in the waste water discharge. The experiments indicated that photocatalyst 1 is stable after photocatalytic experiment and could be reused further as catalyst for photodegradation of another batch of MV. The possible mechanism for the photocatalytic activity of 1 against MV has been addressed using band gap calculation by taking assistance of density of states (DOS) and partial DOS (pDOS) calculations.