BiPO4/BiOBr p–n junction photocatalysts: One-pot synthesis and dramatic visible light photocatalytic activity

BiPO4/BiOBr p–n junction photocatalysts were successfully synthesized via a facile one-pot solvothermal method. The products were characterized by XRD, FE-SEM, HRTEM, XPS, DRS, PL and EIS. The obtained BiPO4/BiOBr composites were constructed by inlaying BiPO4 nanoparticles into BiOBr hierarchical microspheres. Compared with BiPO4 and BiOBr, they exhibited significantly enhanced visible light photocatalytic activity towards the degradation of Rhodamine B (RhB). Among them, 10% BiPO4/BiOBr showed the maximum value of the activity, whose degradation rate was about three times higher than that of pure BiOBr. The enhanced photocatalytic activity could be attributed to the formation of the BiPO4/BiOBr p–n junction, which resulted in the effective separation and transfer of photogenerated electron–hole pairs. Moreover, the trapping experiments confirmed that O2− and h+ were the main active species responsible for the degradation of RhB.