A novel poly(triazine imide) hollow tube (PTI)/ZnO heterojunction was prepared by a molten salts method. The photocatalyst was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV-vis diffuse reflectance spectroscopy (DRS) and photoluminescence (PL) spectroscopy, respectively. The results showed the ZnO nanoparticles were successfully coupled into the PTI hollow tube to form PTI/ZnO heterojunction. The degradation of tetracycline hydrochloride (TC) under visible light irradiation was used to evaluate the activity of photocatalyst. The PTI/ZnO-6 wt% heterojunction exhibits the highest photocatalytic activity, which can degrade almost all TC within 90 min. The kinetic constant of degradation reaction with PTI/ZnO-6 wt% heterojunction (0.034 min(-1)) is about 5 times as high as that of the PTI (0.0070 min(-1)). A possible photocatalytic mechanism for heterojunction according to the energy-band theory was proposed. (C) 2018 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. All rights reserved.