Efficient doping to synthesize high-performance Co/Fe-BiOCl photocatalyst assisted by the ion release from novel CoFe2O4 nanofiber reservoir

Metal ion doping is an efficient method to achieve high photocatalytic performance of semiconductors. However, the current synthetic methods by using inorganic salts as doped sources in the precursor reaction system might suffer from ion waste and second pollution. Herein, we developed a novel method by employing electrospun nanofibers as ion reservoir to release metal ions for the synthesis of ion-doped semiconductors with high photocatalytic activity. As demonstrated, Co/Fe co-doped BiOCl photocatalyst (Co/Fe-BOC) was facilely prepared in the presence of CoFe2O4 nanofibers as Co and Fe ion reservoir via a simple solvothermal method. Compared with BiOCl, the resulted Co/Fe-BOC shows increased specific surface area, visible light response as well as separation and transportation efficiencies of photogenerated carriers. Thus, the Co/Fe-BOC exhibits significantly enhanced visible light photocatalytic activity to degrade 99.4% rhodamine B (RhB) within 4 min. This new doping approach not only avoids the ion waste and pollution during the reaction process but also facilitates the separation of the photocatalyst. Moreover, the CoFe2O4 nanofibers could be repeatedly used as ion reservoir to prepare high-performance Co/Fe-BOC. This nanofiber-based ion doping approach provides a novel, universal and promising insight to obtain doped semiconductors with high photocatalytic activity.