Full Length ArticleA new ribbon-ignition method for fabricating p-CuO/n-CeO2 heterojunction with enhanced photocatalytic activity

The p-type CuO/n-type CeO2 heterojunction photocatalyst was synthesized by a facile combination of ribbon-ignition and calcination methods using Cu-Ce amorphous ribbons as precursors. The synthesized sample was characterized by X-ray diffraction (XRD), fourier transform infrared (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and UV–vis diffuse reflectance spectroscopy (DRS). XRD, FTIR and XPS reveal the successful synthesis of CuO/CeO2 composite. The SEM and TEM images show that the sample consists of large amounts of well-dispersed blocky-shaped particles with the size distribution from 20 nm to 2 μm. DRS exhibits the absorption band (about 491 nm) and the band gap energy (2.59 eV) of the CuO/CeO2 composite. The photocatalytic activities of the samples were evaluated by degrading rhodamine B (RhB) dye (10 mg/L) under visible light (λ > 420 nm) irradiation. Compared with pure CuO and CeO2, the CuO/CeO2 exhibited significantly enhanced photocatalytic degradation activity. The reaction rate constant of CuO/CeO2 is 0.18 min−1, which is much higher than those of CuO (0.12 min−1) and CeO2 (0.10 min−1).