Effective photodegradation of cefixime and carvedilol mediated by visibly active MoO3/CoMn2O4/Cu2BaSnS4 photocatalytic system: An insight on photocatalytic mechanism, degradation pathway and by-product toxicity analysis

•Synthesis of MoO3-CoMn2O4-Cu2BaSnS4 QDs achieved by ultrasonication assisted co-precipitation method.•The nanomaterial exhibited excellent photocatalytic performance against cefixime and carvedilol.•The Jahn teller distortion of CoMn2O4 has been suppressed and an effective photocatalytic performance was achieved with the nanocomposite.•The photodegraded intermediates were obtained by GC–MS analysis and was assessed for toxicity with ECOSAR program.•The photocatalytic mechanism was elucidated with a n-p-p heterojunction system.