Synthesis of heterojunction BiVO4/MnO2 graphene ternary nanocomposites with enhanced photocatalytic activities through degradation of rhodamine B and tetracycline hydrochloride

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Our research has resulted in synthesizing highly efficient BiVO4/MnO2 graphene ternary heterostructures prepared with a simple hydrothermal technique. These structures demonstrate exceptional performance in the photodegradation of rhodamine B (RhB) dye and tetracycline hydrochloride (TC). Adding MnO2 and graphene oxide significantly enhanced the absorption of visible light, photocatalytic activity, and surface area of the nanocatalyst. The prepared materials were characterized by XRD, SEM, BET, DRS, and PL spectroscopy. The PL spectra of G/MnBV-4 show less intensity and lower recombination rate, which is beneficial for photocatalytic activity. The as-synthesized G/MnBV-4 material exhibits outstanding photocatalytic activities toward the TC and RhB dye degradation under visible light irradiation. The reaction rate constant of G/MnBV-4 was estimated in the case of RhB and TC as 0.094 min−1 and 0.021 min−1 respectively, showcasing the material's high efficiency. The optimized material (BiVO4/MnO2 graphene) is stable and reusable, with only a 10 % reduction in removal efficiency after five consecutive cycles. Furthermore, the OH− and O2− are active species for removing organic pollutants. In contrast, holes are attributed to a lower effect. This study describes a photocatalytic approach to effectively removing the TC from waste bodies. The enhanced degradation efficiencies were ascribed to developing heterostructures and fast electron transfer between interfaces. Moreover, graphene increased photogenerated charge carriers' surface adsorption properties and charge separation efficiency. Hence, graphene works as an electron trapper and tuning bandgap energy, which plays a significant role in addition to photocatalytic activity.