Novel CeO2-V2O5/rGO tertiary photocatalyst for improved cefotaxime degradation using visible-light

Abstract

In this study, CeO2-V2O5/rGO photocatalytic system was successfully prepared by hydrothermal method and applied for studying cefotaxime photodegradation process by visible light and sunlight catalyzed by CeO2-V2O5/rGO. The photocatalysts were characterized using XRD, SEM, EDX, UV–Vis, and FT–IR techniques. The factors affecting the photocatalytic degradation of Cefotaxime (CTX), including the impact of pH, CTX concentration, and catalyst dosage were examined. Under optimal conditions (1 g/L catalyst dosage, pH 6.0, and 20 mg/L CTX), approximately 99 % of CTX were decomposed by visible light after 150 min at room temperature. Furthermore, the CeO2-V2O5/rGO catalyst showed the highest CTX removal under sunlight irradiation of 88.1 % after 250 min. The degradation process followed very well the pseudo-first-order kinetics (R2 = 0.93–0.96 for the whole range of concentrations) with a rate constant k varied from 0.03 to 0.06 min−1. In real sunlight irradiation, the photocatalytic performance of the system was affected by sunlight intensity and the CTX photodegradation yield was still high (>80 % after 250 min) while COD removal efficiency seemed to be slightly lower than that of color measurement, which might be linked to the formation of intermediates apart from final products like CO2 and H2O. The CeO2-V2O5/rGO photocatalytic system also presented a very good stability and reusability for CTX photodegradation by visible light.