Synthesis of a visible-light-driven Ag₂O-Co₃O₄ Z-scheme photocatalyst for enhanced photodegradation of a reactive yellow dye

The development of an efficient, cost-effective, and stable visible-light-driven photocatalyst for the photodegradation of organic pollutants is a challenging task. Herein, the synthesis and characterization of a Ag₂O-Co₃O₄ Z-scheme photocatalyst and evaluation of its photocatalytic performance are reported. An aqueous solution of a reactive yellow dye was used as a model organic pollutant. Co₃O₄ and Ag₂O-Co₃O₄ were synthesized by precipitation and impregnation methods, respectively. Advanced techniques including XRD, DRS-UV-Vis, SEM, TEM, TGA, and XPS were employed for the characterization of the synthesized Ag₂O-Co₃O₄. The prepared materials were tested as a catalyst for the degradation of the reactive yellow dye. It was found that coupling of Ag₂O with Co₃O₄ enhanced the photocatalytic performance from 55 to 100% towards a 50 mL dye solution containing 100 mg L⁻¹ of dye. The rate constant for Ag₂O-Co₃O₄ catalyzed photodegradation of the reactive yellow dye was 2.8 times higher than the rate constant with Co₃O₄. The dependence of photocatalytic performance on experimental parameters like catalyst dosage, Ag₂O content, recycling of the catalyst, and concentration of the dye was also investigated. The as-prepared Ag₂O-Co₃O₄ was found to be an efficient, cost-effective, and stable Z-scheme photocatalyst for the photodegradation of the reactive yellow dye under visible light irradiation.