Efficient mineralization of organic pollutants by in-situ synthesized illite/bismuth-based heterojunction photocatalytic composites

•A series of illite/bismuth-rich bismuth oxyiodide photocatalytic composites were fabricated.•Layered structure was constructed via in-situ hydrolysis and calcination process.•The composite exhibit excellent BPA and TH removal and mineralization activities.•The well-matched band alignment and more active sites lead to more ·O2– release.•Potential TH degradation pathways were detected through LC-MS spectra.