Heterojunction formation between AgNbO₃ and Co₃O₄ for full solar light utilization with improved charge-carrier...

In the present study, the charge-carrier recombination of visible light active perovskite silver niobate (AgNbO₃) was reduced by forming heterojunction with Co₃O₄ through simple impregnation and calcination route. The loading percentage of Co₃O₄ was varied as 2, 5, and 10 wt.%. The XRD study revealed reduced interlayer spacing in the composite due to the replacement of the bigger Ag⁺ ions by the smaller Co²⁺ and Co³⁺ ions of Co₃O₄. It was observed that the light harvesting efficiency of the materials was increased with increased loading of Co₃O₄. The TEM and XPS analysis confirmed the presence of Ag nanoparticles over the perovskite in the composite. The electrochemical analysis revealed enhanced charge-carrier number density and increased charge-carrier lifetime in the composite as a result of the presence of both silver and cobalt ions in the lattice. Further this enhanced charge-carrier separation of the composites was established through photocatalysis of Bisphenol-A under both solar and LED light. Charge-trapping study indicated *O₂^- and *OH as the major radicals involved and Z-scheme as the predominant charge transfer pathway for generation of these reactive oxygen species.