WO3/Ag2CO3 Mixed Photocatalyst with Enhanced Photocatalytic Activity for Organic Dye Degradation.

The development of an efficient photocatalyst with superior activity under visible light has been regarded as a significant strategy for pollutant degradation and environmental remediation. Herein, a series of WO3/Ag2CO3 mixed photocatalysts with different proportions were prepared by a simple mixing method and characterized by XRD, SEM, TEM, XPS, and DRS techniques. The photocatalytic performance of the WO3/Ag2CO3 mixed photocatalyst was investigated by the degradation of rhodamine B (RhB) under visible light irradiation (λ > 400 nm). The photocatalytic efficiency of the mixed WO3/Ag2CO3 photocatalyst was rapidly increased with the proportion of Ag2CO3 up to 5%. The degradation percentage of RhB by WO3/Ag2CO3-5% reached 99.7% within 8 min. The pseudo-first-order reaction rate constant of WO3/Ag2CO3-5% (0.9591 min-1) was 118- and 14-fold higher than those of WO3 (0.0081 min-1) and Ag2CO3 (0.0663 min-1). The catalytic activities of the mixed photocatalysts are not only higher than those of the WO3 and Ag2CO3 but also higher than that of the WO3/Ag2CO3 composite prepared by the precipitation method. The activity enhancement may be because of the easier separation of photogenerated electron-hole pairs. The photocatalytic mechanism was investigated by free radical capture performance and fluorescence measurement. It was found that light-induced holes (h+) was the major active species and superoxide radicals (·O2 -) also played a certain role in photocatalytic degradation of RhB.