In-situ fabrication of 3D hierarchical flower-like β-Bi2O3@CoO Z-scheme heterojunction for visible-driven simultaneous degradation of multi-pollutants

•A novel β-Bi2O3@CoO heterojunction was well designed and in-situ fabricated.•The 3D hierarchical structure benefited the light-harvesting, thus improved activity.•The heterojunction showed enhanced catalysis for removing CTC + TCH + OTC mixture or NB.•Possible degradation paths were assumed based on the identification of intermediates.•A direct Z-scheme interfacial charge transfer mechanism in β-Bi2O3@CoO was verified.