Fabrication of nano-dandelion magnetic TiO2/CuFe2O4 doped with silver as a highly visible-light-responsive photocatalyst for degradation of Naproxen and Rhodamine B

Abstract

Nano-dandelion TiO2 and magnetic CuFe2O4 were synthesized with hydrothermal and sol–gel processes, respectively. A series of composites containing different amounts of CuFe2O4 and Ag were also prepared using a photoreduction method. The composites were subsequently used for photodegradation of Naproxen and Rhodamine B under UV–Vis light irradiation. The synthesized photocatalysts were characterized by XRD, FTIR, FESEM, EDX, TEM, BET-BJH, DRS, and PL analyses. XRD and FESEM results confirmed the successful synthesis of the dandelion structure for the composites. The VSM analysis also demonstrated the enhancement of magnetic properties of composites. DRS results indicated that CuFe2O4 loading and Ag doping resulted in a decrease in the band gap energy and enhanced absorption of light in the visible region as compared with pure TiO2. The presence of CuFe2O4 and Ag also increased charge transfer by decreasing electron-hole recombination rates by creating a Schottky-barrier interface which was indicated by the PL spectra. The composite containing 20% CuFe2O4 and 3% Ag (designated as TC20-3Ag) showed better performance as compared with other photocatalysts for photodegradation of Naproxen (92.56%) and Rhodamine B (91.16%) over a 150-minute reaction time. The sample also exhibited good stability after 5 cycles. The effects of operating parameters such as the pH of the solution, the photocatalyst dosage, and initial pollutant concentration were also investigated. It was found that a pseudo-first-order model adequately described the photodegradation kinetics. The results indicated that superoxide and holes were reactive species, and a possible mechanism for the photodegradation of Naproxen by TC20-3Ag was suggested.