Preparation and Photocatalytic Activity of Ag@AgCl Modified natase TiO2 Nanotubes

Abstract

The combination of TiO2 nanotubes and a surface plasmon resonance (SPR) photocatalyst used their large adsorption capacity and wide visible light response, respectively, and a synergistic effect to enhance photocatalytic activity under visible light irradiation. Anatase TiO2 nanotubes were prepared by hydrothermal synthesis, a hydrogen peroxide treatment, and calcination at 400 °C. AgCl nanoparticles were then loaded onto the TiO2 nanotubes by a precipitation reaction, and some of the AgCl particles were reduced to Ag particles under halogen tungsten lamp irradiation. This gave a visible light SPR photocatalyst of [email protected]/TiO2 nanotubes that exhibited high photocatalytic activity, which was due to its large adsorption capacity, wide visible light response due to the SPR effect, fast separation of photogenerated electron-hole pairs, and strong oxidizing ability of Cl0 generated by combining Cl− ions with photoexcited holes. Methylene blue dye was thoroughly decolorized within 1 h in the presence of this photocatalyst under visible light irradiation. In addition, the photocatalyst was stable after recycling the photocatalytic reaction five times. ：首先采用水热合成法和双氧水处理制备了具有锐钛矿相的 TiO2 纳米管, 然后通过沉淀和光化学反应将 [email protected] 纳米粒子负载于其上, 从而制得 TiO2 纳米管负载的表面等离子体光催化剂. 结果表明, 经 [email protected] 纳米粒子修饰后, 锐钛矿相 TiO2 纳米管因表面等离子共振效应而对可见光具有明显的响应, 光生电子-空穴对更容易分离, 因而 TiO2 纳米管的可见光催化活性提高. 该催化剂对亚甲基蓝分子具有很强的吸附能力, 可见光下照射 1 h 后即可完全降解脱色. 另外, 该光催化剂重复使用 5 次后, 亚甲基蓝脱色率仍保持在 90% 以上.