Photocatalytic reduction of 4-nitroaniline in aqueous solution using BiOCl/BiOBr/rGO ternary heterojunction under simulated UV–visible light irradiation

Abstract: BiOCl/BiOBr/rGO ternary heterojunctions were synthesized and characterized, and their photocatalytic activities were examined. Three different rGO mass ratios were incorporated into BiOCl_75%BiOBr_25%; 1% rGO, 3% rGO, and 5% rGO, respectively. The successful incorporation of rGO into the composites was confirmed using powder X-ray diffraction (PXRD). Furthermore, calculated band gap, elemental composition, and composites’ morphology were investigated using UV–visible (UV–Vis) diffuse reflectance spectroscopy (DRS), energy-dispersive X-ray spectroscopy (EDX), and scanning electron microscopy (SEM), respectively. The photocatalytic activities of the ternary heterojunctions were evaluated toward the photocatalytic reduction of 4-nitroaniline (4-NA) in aqueous solution. Experimental results reveal that rGO incorporation enhances the activity of the prepared heterojunction photocatalysts, where photocatalyst containing 5% rGO exhibited the highest activity achieving rate of 0.84 min⁻¹. Graphic abstract: [Figure not available: see fulltext.]