Effect of surfactant PEG on the property control of Bi₂O₃ and its photocatalytic activity

A detailed investigation into the effect of the poly(ethylene glycol) (PEG) addition mass on the bismuth (III) oxide (Bi₂O₃) photocatalyst is limited but necessary. Bismuth (III) oxide/PEG photocatalysts with different morphologies were prepared with different PEG mass via the solvothermal method and characterized for phase, morphology, optical absorption properties, elemental composition and specific surface area. The results indicated that all bismuth (III) oxide photocatalysts with different additions (Bi₂O₃/PEG-m_x) were pure β-bismuth (III) oxide phases, comprising larger platelike and smaller particle-like particles. Enhanced photocatalytic activity was attributed to increased larger specific surface area with PEG below 10 g. With 12 g of PEG, the formation of surface pores on plate-like bismuth (III) oxide impoved light penetration and utilization. Bi2O3/PEGm12 exhibited optimal photocatalytic activity, achieving over 90% bisphenol A(BPA) degradation after 180 min at 0.6 g·L⁻¹ under visible light. Bismuth (III) oxide /PEG-ty prepared below 140°C showed poor activity, while above 160°C, high activity was observed. Bismuth (III) oxide/PEG effectively mineralize over 80% of bisphenol A into inorganic molecules and water under the co-oxidation of superoxide radicals (·O₂⁻) and holes (h⁺). This is the first detailed research on the regulation and modification of β-bismuth (III) oxide by PEG, which may provide new insights into the photocatalytic technology.