Synthesis and Enhanced Visible‐Light Photocatalytic Activity of Tm 3+ /Yb 3+ Co–Doped Bi 3.64 Mo 0.36 O 6.55

Construction lamellar BaFe12O19/Bi3.64Mo0.36O6.55 photocatalyst for enhanced photocatalytic activity via a photo-Fenton-like Mo6+/Mo4+redox cycle

The novel BaFe₁₂O₁₉/Bi_3.64Mo_0.36O_6.55 composite materials were constructed as magnetically recyclable photo-Fenton-like degradation systems. The composite catalyst not only promoted the effective transfer of photo-generated electrons and improved the Mo⁶⁺/Mo⁴⁺ cycle consequent, but also activated hydrogen peroxide to generate oxidizing free radicals. BaFe₁₂O₁₉/Bi_3.64Mo_0.36O_6.55-0.25 exhibited an outstanding degradation performance for tetracycline hydrochloride it is 1.3 times to Bi_3.64Mo_0.36O_6.55. The thermal catalytic performance of the Bi_3.64Mo_0.36O_6.55 monomer is similar to that of the BaFe₁₂O₁₉/Bi_3.64Mo_0.36O_6.55 material without light. However, the removal rate of BaFe₁₂O₁₉/Bi_3.64Mo_0.36O_6.55 material reaches 84.5% after 60 min with light, far exceeding that of Bi_3.64Mo_0.36O_6.55 material. By way of the contrast experiment with light and without light, it is further demonstrated that interfacial interaction between BaFe₁₂O₁₉ and Bi_3.64Mo_0.36O_6.55 acted a key role in the photocatalytic reaction system. It is also a good advantage that pollutants can be efficiently degraded without adjusting the pH. The characterization of photocurrent and X-ray photoelectron spectroscopy (XPS) also further proved the synergy between the two materials, which is useful to the separation of electrons and holes. The synergy ultimately improves the degradation performance. Besides, BaFe₁₂O₁₉/Bi_3.64Mo_0.36O_6.55 can be easily separated by an external magnetic field after the photocatalytic activity reaction owing to BaFe₁₂O₁₉'s magnetic properties. It provides a new research idea for the construction and iron-based heterogeneous Fenton-like system for magnetic degradation of antibiotics.

Preparation of Pt/γ-Bi2MoO6 Photocatalysts and Their Performance in α-Alkylation Reaction under Visible Light Irradiation

Bi(NO3)3·5H2O and (NH4)6Mo7O24·4H2O were used as precursors to synthesize flaky γ-Bi2MoO6 samples by a hydrothermal method, and Pt/γ-Bi2MoO6 samples with different mass fractions were prepared by an NaBH4 reduction method. Alpha alkylation of benzyl alcohol and acetophenone with photocatalysts under visible light irradiation was performed, and the activity of 4 wt % Pt/γ-Bi2MoO6 (γ-Bi2MoO6 was prepared by a nitric acid method, pH = 9, and reaction temperature 180 °C) was the best. The photocatalytic reaction conditions were optimized by changing various kinds of variables, such as the type of catalyst, solvent, and base, and the amount of base, catalyst, and reactant. The optimal conditions for the organic reaction were 75 mg 4 wt % Pt/γ-Bi2MoO6, 6 mL n-heptane, 1.2 mmol NaOH, 1 mmol acetophenone, and 3 mmol benzyl alcohol. Under the optimal reaction conditions, the effects of different light wavelengths and light intensities on the reaction were measured, and the cycling ability of the photocatalyst was tested. After five cycles, the photochemical properties of the catalyst were relatively stable. Finally, the active substances were identified (such as electrons (e-), holes (h+), hydroxyl radicals (•OH), and superoxide radicals (•O2-).