One-step low-temperature synthesis of 0D CeO₂ quantum dots/2D BiOX (X = Cl, Br) nanoplates heterojunctions for highly boosting photo-oxidation and reduction ability

0D/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 photocatalytic 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 photoexcited 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 0D/2D Bi-based heterojunction materials with high photocatalytic performance.