Facile synthesis of Z-scheme CeO2@AgBr heterojunction for improved dye degradation

CeO2 nanorods were synthesized by the hydrothermal method and coupled with AgBr via deposition approach. X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Brunauer-Emmet-Teller (BET) and diffuse reflection spectroscopy (DRS) were used to characterize the structure, morphology and optical properties of the samples. The photoinduced charge separation efficiency was determined by transient photocurrent response and photoluminescence (PL) spectra. The effect of CeO2 loading on the Rhodamine B (RhB) degradation in CeO2@AgBr composites was also investigated. The results indicated that 40 wt%-CeO2@AgBr photocatalyst demonstrated the highest photocatalytic activity than pure CeO2 and AgBr. The trapping experiment showed that holes (h+) and superoxide radicals (•O2−) were the main active species for the degradation of RhB. The improved photocatalytic activity of CeO2@AgBr catalysts were attributed to the formation of Z-scheme heterojunction, which effectively inhibited the recombination of photoinduced electron-hole pairs.