From green chemistry to clean water: Bi2O3 Nanoparticles as Photocatalyst

Abstract

Photocatalysis is one of the potential applications for environmental cleanup with unique properties like thermal, optical, electrical and structural properties. A facile green synthesis method was employed to synthesize Bi₂O₃ nanoparticles using Costus igneus leaf extract as a fuel for combustion synthesis. Costus igneus leaf extract was used as a natural source of reducing agent, capping, and stabilizing agents in this study which is successfully synthesize the bismuth oxide nanostructures. Green synthesis of Bi₂O₃ nano particles are very effective due to its advantageous characteristics such as non-toxicity, environmentally friendly synthesis, cost-effectiveness and the ability to achieve uniform particle formation. The calcinated product was characterized using spectroscopic techniques namely X-ray diffraction (XRD), scanning electron microscope (SEM) and energy dispersive X-ray spectroscopy (EDXS). The synthesized Bi₂O₃ nanomaterials were subjected for photocatalytic property using methylene blue as a model organic pollutant present in waste water. The superb photocatalytic activity of the nanoparticles has its unique features, i.e., large surface area, defective states structure, visible-light-triggered band, good electrical conductivity. These factors enhance the light-harvesting, charge-separation, electron-excitation and charge transport properties of the synthesized bismuth oxide NPs. The study revealed that Bi₂O₃ nanoparticles showed 98% degradation efficiency within two hours of visible light irradiation. Furthermore, variations of pH and dye concentration parameters were performed to optimize the photodegradation efficiency of the as synthesized Bi₂O₃ nanoparticles. All of these factors work together to make environmental friendly Bi₂O₃ nanoparticles for wastewater treatment applications.