In this work, Bi.sub.4NbO.sub.8Cl associated with Bi.sub.24O.sub.31Cl.sub.10 and Bi.sub.3NbO.sub.7 was prepared by a solid-state method. During the removal of impurities, the heterostructure was formed simultaneously. The effect of acid on the type of heterostructure and photocatalytic performance of the prepared samples was studied. Under low-acetic acid concentrations, Bi.sub.4NbO.sub.8Cl/BiOCl/Nb.sub.2O.sub.5 composites could be obtained, while Bi.sub.4NbO.sub.8Cl/BiOCl was formed under high acidic conditions. Compared with the samples prepared by the solid-state method, the two types of heterojunctions Bi.sub.4NbO.sub.8Cl/BiOCl/Nb.sub.2O.sub.5 and Bi.sub.4NbO.sub.8Cl/BiOCl both showed improved photocatalytic performance. In particular, Bi.sub.4NbO.sub.8Cl/BiOCl/Nb.sub.2O.sub.5 prepared with ethanol/acetic acid ratio of 1:1 possessed the best photocatalytic activities, with RhB and CIP could be totally degraded within two hours, while the degradation rate of BPA was about 67% within three hours.