Fabrication of ternary nano-heterojunction via hierarchical deposition of α-Fe2O3 and β-La2S3 on cubic CoCr2O4 for enhanced photodegradation of doxycycline.

• CoCr 2 O 4 /α-Fe 2 O 3 /β-La 2 S 3 (CFL) nano-heterojunction is being reported for the first time. • Ultrasonication-assisted co-precipitation combination method was employed to synthesis CFL. • CFL ensured efficient separation of the photogenerated charges. • O 2 ^.- and OH^. radicals played a major role in the degradation of doxycycline. • CFL exhibited excellent stability and reusability. The current study offers the design of a novel photocatalyst for the effective removal of pharmaceuticals wherein the heterojunction was constructed with the objective of capturing maximum solar spectrum and to ensure effective separation of photogenerated charge carriers. The nano-heterojunction was fabricated through ultrasonication-assisted co-precipitation method by the hierarchical deposition of α-Fe 2 O 3 and β-La 2 S 3 on cubic CoCr 2 O 4 spinel. The fabricated nanomaterials were extensively characterized by using XRD, Raman, FTIR, XPS, SEM, TEM, EDAX, PL, EIS, BET, and DRS. The photoluminescence and EIS analysis revealed the mitigated charge carrier recombination in CoCr 2 O 4 /α-Fe 2 O 3 /β-La 2 S 3 (CFL) that resulted in superior photodegradation of doxycycline (DOX) (92.83 %) under visible light irradiation. Mineralization percentage of 92.5 % was affirmed by TOC analysis. Further, the influence of pH, ions, concentration of DOX and CFL dosage on the photodegradation process was studied. The active participation of the reactive species involved in the reaction were identified by scavenging assay and ESR. Finally, a possible photocatalytic mechanism of CFL for the degradation of DOX with underlying pathway is proposed with the help of GC–MS/MS analysis. The study highlights the great promise of CFL photocatalyst as well as the potential of n-n-p heterojunction for appliances in the photodegradation of organic pollutants. [ABSTRACT FROM AUTHOR]