Solvothermal synthesis of novel ternary BiOI–BiOBr–NiO nanophotocatalyst with improved solar light photocatalytic activity

A novel class of heterojunction BiOI–BiOBr–NiO has been synthesized through solvothermal-precipitation route. Novel as-prepared nanophotocatalysts are highly efficient under simulated sunlight illumination for AO7 degradation. Even though, NiO possess no photocatalytic efficiency, its combination with BiOBr–BiOI provides exceptional high photocatalytic performance due to more effective photo-generated electron–hole separation through the heterojunction semiconductor construction. XRD, FESEM, EDX, BET, FTIR and DRS analysis were applied to identify the physical, chemical and optical properties of the synthesized BiOI–BiOBr–NiO heterojunctions. The results showed remarkable increase of photoactivity of BiOI–BiOBr–NiO (6:3:1) in comparison with corresponding heterostructures. XRD confirms construction of BiOBr–BiOI over NiO nanoparticles. In addition, 3D image of synthesized samples affirms proper roughness and porosity. The effect of parameters including catalyst loading, pH and dye concentration has been examined. According to recycling tests and XRD of used sample, the novel heterojunction system considered to be photo table.