S-doping α-Fe2O3 induced efficient electron-hole separation for enhanced persulfate activation toward carbamazepine oxidation: Experimental and DFT study

•S-doped α-Fe2O3 was synthesized successfully via a three-steps method.•UV/PS/S-α-Fe2O3 process presented excellent performance for CBZ removal.•S-α-Fe2O3 exhibited slower electrons-holes recombination rate and narrower band gap.•·OH, SO4-·, O2–· and h+ were responsible for CBZ degradation in UV/PS/S-α-Fe2O3 process.•The hydroxylation, deamination, decarbonylation, ketonization and ring cleavage were the main degradation routes.