One-pot electrochemical preparation of BiOCl/BiPO4 double-layer heterojunction film with efficient photocatalytic performance

Abstract A BiOCl/BiPO 4 double-layer heterojunction film on metal Bi plate with reduced recombination of photo-induced carriers has been successfully prepared by one-step electrochemical anodization process. The morphology characterizations displayed that the double-layer film consisted of BiPO 4 rods array at the bottom and BiOCl nanosheets on the top. Meanwhile, the control experiments indicated that the BiPO 4 rods array was transformed by BiOCl rather than Bi 3+ reacting with PO 4 3− directly. In addition, the resulting BiOCl/BiPO 4 heterojunction film exhibited excellent photocatalytic activity and stability on the degradation of phenol comparing with pure BiOCl film. Transient photocurrent measurements and PL spectra proved that the enhanced photocatalytic performance of BiOCl/BiPO 4 heterojunction film was attributed to the effective separation of photo-generated electron-hole pairs excited on BiOCl. Moreover, O 2 − and OH played a crucial role in the photodegradation process of phenol. Based on these analytical results, a plausible photocatalytic mechanism has been proposed.