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.