Heterojunction formation between AgNbO and CoO for full solar light utilization with improved charge-carrier separation.

In the present study, the charge-carrier recombination of visible light active perovskite silver niobate (AgNbO) was reduced by forming heterojunction with CoO through simple impregnation and calcination route. The loading percentage of CoO 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 Co and Co ions of CoO. It was observed that the light harvesting efficiency of the materials was increased with increased loading of CoO. 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 *O and *OH as the major radicals involved and Z-scheme as the predominant charge transfer pathway for generation of these reactive oxygen species.