Insight into CeO2 decorated hierarchical tremella-like Ag/g-C3N4 boosting organic contaminants removal: Maximum redox capacity and local surface plasma resonance effects

Abstract

Many optimization strategies have been applied to the construction of materials with excellent organic contaminants removal activity, whereas the interaction mechanisms of these strategies have rarely been revealed. Here, based on the analysis and evaluation of CeO2-decorated hierarchical tremella-like Ag/g-C3N4 (Ce@15-AC) materials, the mechanism of oxidation activity enhancement is studied in depth. Finite–difference time–domain (FDTD) simulations and density functional theory (DFT) calculations reveal the mechanism of local surface plasma resonance (LSPR) effects and interfacial electric fields. The synergistic effect of the Z-scheme electrons transfer direction and Ce4+/Ce3+ redox couple conversion enable Ce@15-AC to achieve the maximum redox capacity. The hierarchical structure can generate scattering and reflection of sunlight and provide a variety of channels for light transmission. Moreover, experiments and characterizations prove that Ce@15-AC material has fantastic photoelectrochemical, physical and optical properties. The removal efficiency of tetracycline (TC) by Ce@15-AC reaches 91.7% within 40 min (20 mg/L, 100 mL), and TC is almost completely degraded after 60 min. The apparent reaction rate constant (k) of Ce@15-AC is approximately 0.05974 min−1, which is 10.71 times higher than 3DT-CN (0.00558 min−1). This work provides a meritorious instance in the advanced oxidation of organic contaminants application field.