Single-step sonochemical synthesis of Cu2O-CeO2 nanocomposites with enhanced photocatalytic oxidative desulfurization.

In this paper, for the first time, composite nanostructures of Cu2O-CeO2 were prepared by a facile and single-step sonochemical method for thiophene photocatalytic oxidative desulfurization. Sonication was performed utilizing a high-intensity ultrasonic probe with a maximum output power of 80 Wcm-3 and operating frequency at 20 kHz. The direct effect of ultrasonic waves on the composition and morphology of the obtained products was also evaluated and it was found that under ultrasonic irradiation, Cu2O-CeO2 can be produced while the main product in the absence of ultrasonic waves is CuO-CeO2. Cu2O-CeO2 exhibits much higher photocatalytic efficiency (84%) than CuO-CeO2 (39%) due to its higher light absorption and electron synergistic effect. The effect of Ce:Cu on photocatalytic efficiency was examined by considering the ratios of 1:0.25, 1:1, 0.5:1, and 0.25:1 and yields of 64, 81, 84, and 76% were obtained, respectively. This indicates that there is an optimal value for the Ce:Cu ratio in the Cu2O-CeO2 nanocomposite.