Well dispersed α-Fe2O3@Fe3O4 nanoparticles (7 nm) supported on mesoporous nitrogen doped titanium dioxide (N-TiO2) are synthesized by deposition self-assembly route and their performances as photocatalysts toward methylene blue (MB) degradation are evaluated. The results illustrate that the spherical yolk-shell structure of α-Fe2O3@Fe3O4@N-TiO2 at the loading of 1%; of excellent SBET (187 m2 g−1) and pore volume (0.50 cm3 g−1), achieved high photocatalytic performance for the MB degradation (20 ppm, λ > 420 nm, lamp power = 160 W) under visible light illumination (k = 0.059 min−1). The influence of the interface formation between α-Fe2O3@Fe3O4 and n-TiO2 affects severely the charges separation efficiency and enhances the electron transfer to keep on the existence of Fe3+/Fe2+ moieties; those take significant role in the reaction mechanism. The existence of the latter junction is affirmed via XRD, TEM-SAED, Raman and FTIR techniques whereas, the photogenerated charges, their separation together with their transport and recombination rates are depicted via photoluminescence, electrical conductivity, incident photon to current efficiency (IPCE), cyclic voltammetry (CV) and impedance (EIS) measurements. The catalyst loading, zero point charge, pH variation, total organic carbon (TOC%) and the effect of lamps power are thoroughly investigated. The 1%α-Fe2O3@Fe3O4@N-TiO2 photocatalyst also indicated high activity as a Fenton-like reagent accomplishing the MB degradation (100% removal) in 35 min with a rate of 0.07 min−1 at H2O2 concentration of 0.4 mM. The obtained results demonstrate that the heterojunction nanoscaled materials possess superior visible-light driven photocatalytic activity with appreciable recyclability and promising utilization as a supercapcitor (426 F g−1 at scan rate of 5 mV s−1) device. |
