Abstract
<title>Abstract</title> <p> Based on the advantages of electrodeposition preparation, we prepared the CeO <sub>2</sub> -Co <sub>2</sub> O <sub>3</sub> /BiVO <sub>4</sub> via an electrodeposition method under phosphate buffer solution whereby BiVO <sub>4</sub> and Co <sub>2</sub> O <sub>3</sub> /BiVO <sub>4</sub> catalysts were synthesized through impregnation and calcination, respectively. X-ray diffractometer, scanning electron microscopy, and X-ray photoelectron spectrometry, characterized these catalysts. The most suitable wavelength for the irradiation of CeO <sub>2</sub> -Co <sub>2</sub> O <sub>3</sub> /BiVO <sub>4</sub> was screened, and it was found that the highest efficiency for the catalytic degradation of wastewater was achieved at a visible light wavelength of 435 nm, while three-dimensional fluorescence spectroscopy assessed their wastewater degradation efficiency. Meanwhile, the results revealed that the CeO <sub>2</sub> loading could effectively reduce the recombination of electron-hole for Co <sub>2</sub> O <sub>3</sub> /BiVO <sub>4</sub> , thus improving the visible photocatalytic degradation performance in wastewater. Using the CeO <sub>2</sub> -Co <sub>2</sub> O <sub>3</sub> /BiVO <sub>4</sub> , chemical oxygen demand(COD) degradation of biochemical effluent in the coking wastewater reached 98% at a 6 h light time and at 0.5 g/L dosage. It was 13% higher than that of the binary catalyst Co <sub>2</sub> O <sub>3</sub> /BiVO <sub>4</sub> under the same conditions, demonstrating the obvious significance of CeO <sub>2</sub> . Further analysis of the influence of CeO <sub>2</sub> -Co <sub>2</sub> O <sub>3</sub> /BiVO <sub>4</sub> dosage on degradation efficiency and the effect of solution pH on the photo-degradation efficiency of CeO <sub>2</sub> -Co <sub>2</sub> O <sub>3</sub> /BiVO <sub>4</sub> revealed that the optimal degradation could be achieved under 0.5g/L CeO <sub>2</sub> -Co <sub>2</sub> O <sub>3</sub> /BiVO <sub>4</sub> dosage and pH 7.0. Finally, the degradation mechanisms of CeO <sub>2</sub> , Co <sub>2</sub> O <sub>3</sub> , and BiVO <sub>4</sub> were analyzed, and the advantages of CeO <sub>2</sub> -Co <sub>2</sub> O <sub>3</sub> /BiVO <sub>4</sub> in generating hydroxyl radicals were compared and demonstrated. </p>