Mechanistic study for enhanced photocatalytic degradation of acetaminophen by Fe(III) doped TiO2 hollow submicrospheres

[Display omitted] •Fe-doped TiO2 offers inherent advantages in photo-Phenton reaction over other approaches.•Fe doping leads to O-Ti-O bond structural distortion along Z-axis and Fe-O hybridized bands.•Fe(III)/Fe(II) redox is enhanced by fast charge transfer due to the hybrid bands in Fe-TiO2 photocatalyst.•Fe-TiO2 hollow submicrosohere has good permeability and high specific surface area. The Fe (III) ions incorporated into TiO2 hollow submicrospheres are an excellent photocatalyst that could improve the catalyst activity by varying experimental parameters like controlling the flow rate, rotation speed, and contaminant concentration. Fe-TiO2 hollow submicrospheres with different Fe wt% in TiO2 were prepared. Our studies revealed that 2.5 wt% Fe-TiO2 has the best photocatalyst activity to generate strong oxidizing hydroxyl radicals during the photocatalytic degradation reaction. Ex-situ L and K-edge of Ti and Fe X-ray absorption near edge structure (XANES) spectra showed that Fe3+ ions in the 2.5 wt% sample produced more structural distortions in the TiO6 octahedral symmetry. Further, in-situ XANES Ti and Fe 3d spectral changes above the Fermi level (EF) revealed an increased electron charge transfer attributed to the Fe 3dz2- O 2pz orbital hybridization. Fe(III) doping not only increases the interaction between transition metal (Fe and Ti) 3d orbitals in TiO2, but also promotes the Fe(III)/Fe(II) redox kinetics and the associated photo-Fenton degradation of acetaminophen. Taking advantage of the magnetic property of the catalyst, the samples can be effectively recycled by applying a magnetic field.