One-step low-temperature synthesis of OD CeO2 quantum dots/2D BiOX (X = Cl, Br) nanoplates heterojunctions for highly boosting photo-oxidation and reduction ability

OD/2D heterojunctions, especially quantum dots (QDs)/nanoplates have attracted noteworthy attention for use of the high charge mobility of photoinduced electrons and holes. Herein, we report a novel one-step low-temperature route for the controlled synthesis of CeO2 QDs/BiOX (X = Cl, Br) nanoplates heterojunctions with the self-created in-built Ce4+/Ce3+ redox centers. The as-prepared heterojunctions exhibited outstanding photo-catalytic abilities not only for the oxidation of tetracycline (TC) but also for the reduction of hexavalent chromium (Cr6+) although under 5 W white LED light irradiation. The considerably enhanced capabilities were attributed to the improvement of light absorption and the highly effective transfer and separation of photo-excited carriers, which encouraged by the strong synergistic effects of inner Ce4+/Ce3+ redox centers and the formation of intimately contacted interface between CeO2 QDs and BiOX nanoplates. Meanwhile, the likely degradation pathway of TC was proposed on the basis of the intermediate products detected by GC MS, and the appearance photocatalytic mechanisms were also discussed in detail. This work could open new possibilities to provide some insight into a facile, energy saving and environmental friendly pathway for synthesizing versatile OD/2D Bi-based heterojunction materials with high photocatalytic performance.