Photocatalytic oxidation of Rhodamine B with ferric oxide thin films under solar illumination

Thin films of iron oxide are synthesized by spray pyrolysis technique using ferric chloride as precursor in non-aqueous medium. The effect of solution concentration onto photochemical, structural, morphological, optical, luminescence and thermal properties has been investigated. Structural analysis confirms the rhombohedral crystal structure with strong (1 1 0) orientation. Raman spectrum reveals that the deposited films contain α-phase of Fe2O3 (hematite). The SEM images of optimized Fe2O3 thin films show microneedle like structure with varying grain size from 75 to 120 nm. The observed direct band gap is about 2.0 eV for Fe2O3 thin film. Room temperature photoluminescencespectra showed three pronounced emission peaks for all concentrations. The photocatalytic oxidation of Rhodamine B with hematite Fe2O3 thin films under solar illumination is investigated. The first order rate constants for this heterogeneousphotocatalysis are evaluated as a function of the initial concentration of Rhodamine B (RhB). The extent of mineralization of degraded sample is confirmed by total organic carbon (TOC) andchemical oxygen demand (COD)analysis. This work suggests that prepared iron oxide photoelectrodes demonstrate an excellent ability to remove toxic dyes from industrial wastewater.