The synthesis of a new Mn(II)-based metal–organic framework (MOF), denoted as [Mn3(bpyp)3(HCOO)4(H2O)2·2NO3–·H2O]n (1) (bpyp = 2,5-bis(pyrid-4-yl)pyridine) was confirmed by single-crystal X-ray diffraction (XRD), UV–visible, Fourier-transform infrared spectroscopy (FT-IR), and thermogravimetric analysis (TGA). 1 exhibits a new 3D porous network with a (3,4,5)-connected topology. The photocatalytic degradation capability of 1 was investigated against various antibiotics, including dimethonidazole (DTZ), nitrofurazone (NFZ), nitrofurantoin (NFT), tinidazole (TDZ), and furazolidone (FZD). 1 exhibited exceptional photocatalytic activity against NFT, with a dosage of 5 mg/L resulting in a remarkable degradation efficiency of 96.81 % for 40 ppm NFT. Furthermore, a proposed photodegradation mechanism was investigated through radical trapping experiments, providing insights into the underlying pathways involved in the photocatalytic degradation process.