Synthesis of double Z-scheme CdS/Bi2O2CO3/BiOCl heterojunction photocatalysts for degradation of rhodamine B under visible light

Abstract

In this paper, novel CdS/Bi₂O₂CO₃/BiOCl photocatalysts with a double Z-scheme heterojunction were successfully obtained by a simple one-step hydrothermal method. XRD, SEM, and TEM were used to verify the formation of the catalysts, and FTIR and XPS were used to evaluate their chemical composition and binding energy. To evaluate the performance of these photocatalysts, the degradation of RhB was performed under visible light and the effects of the catalyst dose and pH on the photocatalytic performance were examined. The results showed that the 10 mol% CdS/Bi₂O₂CO₃/BiOCl catalyst (0.1 g, pH = 5) showed the best activity, with a degradation rate of 97% in 90 min. The BET results showed that the composites have stronger adsorption properties. Electrochemical test results demonstrated that the Z-scheme heterojunction was responsible for promoting the carrier separation efficiency. The combination of strong visible light absorption and the effective separation of photogenerated electron–hole pairs remarkably enhanced the catalytic activity.