Synthesis and study of Bi_2Ti_2O_7/TiO_2 composites as efficient visible-light-active photocatalysts

• 作 者: Jing Li Yan Xu Wei Yue Yan Chen Xi-Hua Du Shao-Rong Wang
• 机 构: College of Chemical Engineering, China University of Mining and Technology,School of Chemistry and C
• 出 处: Chinese Chemical Letters
• 发表日期: 2016年06期
• 关键词: visible VI irradiation titanate photocatalytic calcination simply tunable reflec

In this work, Bi_2Ti_2O_7/TiO_2 composites were synthesized and studied as potential visible-light-activated photocatalysts in the reduction of aqueous Cr(VI). Bi_2Ti_2O_7/TiO_2 composites with tunable compositions were synthesized via a solvothermal-calcination two-step method, simply by changing the molar ratios of Bi(NO_3)_3·5H_2O to tetrabutyl titanate in the reactants. The compositions, structures and optical properties of the as-synthesized Bi_2Ti_2O_7/TiO_2 composites were characterized by X-ray diffraction, field emission scanning electron microscopy and UV–vis diffuse reflectance spectra. The photocatalytic activity of the as-synthesized Bi_2Ti_2O_7/TiO_2 composites was tested in the reduction of aqueous Cr(VI)under visible-light(λ>420 nm) irradiation, and compared with that of TiO_2 nanoparticles. It was observed that the as-synthesized Bi_2Ti_2O_7/TiO_2 composites exhibited much higher photocatalytic activity than TiO_2 nanoparticles, and the most efficient composite(300 mg) can achieve the complete reduction of Cr(VI) in 300 mL of 50 mg/L K_2Cr_2O_7 aqueous solution under visible-light(λ>420 nm)irradiation in 90 min.

In this work, Bi_2Ti_2O_7 / TiO_2 composites were synthesized and studied as potential visible-light-activated photocatalysts in the reduction of aqueous Cr (VI) .Bi_2Ti_2O_7 / TiO_2 composites with tunable compositions were synthesized via a solvothermal-calcination two-step method, simply by changing the molar ratios of Bi (NO_3) _3 · 5H_2O to tetrabutyl titanate in the reactants. The compositions, structures and optical properties of the as-synthesized Bi_2Ti_2O_7 / TiO_2 composites were characterized by X-ray diffraction, field emission scanning electron microscopy and The photocatalytic activity of the as-synthesized Bi_2Ti_2O_7 / TiO_2 composites was tested in the reduction of aqueous Cr (VI) under visible-light (λ> 420 nm) irradiation, and compared with that of TiO_2 nanoparticles. It was observed that the as-synthesized Bi_2Ti_2O_7 / TiO_2 composites shows much higher photocatalytic activity than TiO_2 nanoparticles, and the most efficient composite (300 mg) can achieve the complete reduction of Cr (VI) in 300 mL of 50 mg / L K 2 Cr 2 O 7 aqueous solution under visible-light (λ> 420 nm) irradiation in 90 min.