Rationally designed C-PANI/BiOBr STEP-scheme heterojunction photocatalyst for boosting photodegradation of 17β-estradiol

•A novel C-PANI/BiOBr S-scheme heterojunction photocatalyt was constructed.•The composite photocatalysts exhibited enhanced light absorption in full spectrum.•C-PANI could adsorb contaminants and concentrate them around the photocatalyst.•The S-scheme mechanism and exposed (110) facets of BiOBr promoted charge transfer.•The possible photodegradation pathways of 17β-Estradiol and mechanism were proposed.