Abstract Photocatalytic reduction of Zn2+, Cu2+ and Pb2+ ions were performed using modified titanium dioxide nanoparticles with histidine (His) and imidazole (IM) as the modifier and characterized by FT-IR, X-RD, FESEM, EDAX, TEM and A.A.S. techniques. The anatase phase titanium dioxide nanoparticles with the size distribution of 25–45 nm were obtained by the Sol–Gel Method. In the case of Cu2+, the reduction reaction was completed in 10 min. The photo-reduction yields of Pb2+ and Zn2+ ions achieved to 98% removal during 60 and 160 min, respectively. The immobilized modifiers on the TiO2 surface accelerate the electron transfer from TiO2 to the metal ion via imidazole bridge upon ultraviolet light irradiation. This photocatalytic reduction could be proceeded through chemisorption, reduction and desorption processes of metal ions on the surface of modified TiO2, sequentially and repeatably. Herein, methanol was played as an artificial electron donor. These hybrid photocatalysts were reused several times without losing efficiency while the highest reduction yield was achieved for TiO2@His NPs. So, modified TiO2 with amino acids could be an excellent candidate for metal ion reduction by an inexpensive method with advantages of high performance, high activity, reusability, easily prepared, easily separate, environmentally friendly and short reaction time.

中文翻译：

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使用氨基酸修饰的二氧化钛纳米粒子高效光催化还原 Zn2+s、Pb2+ 和 Cu2+ 离子

摘要 以组氨酸 (His) 和咪唑 (IM) 为改性剂，采用改性二氧化钛纳米粒子对 Zn2+、Cu2+ 和 Pb2+ 离子进行光催化还原，并通过 FT-IR、X-RD、FESEM、EDAX、TEM 和 AAS 技术进行表征。通过溶胶-凝胶法获得粒度分布为 25-45 nm 的锐钛矿相二氧化钛纳米粒子。在 Cu2+ 的情况下，还原反应在 10 分钟内完成。Pb2+ 和 Zn2+ 离子的光还原率在 60 分钟和 160 分钟内分别达到 98%。在紫外光照射下，TiO2 表面上的固定化改性剂通过咪唑桥加速电子从 TiO2 转移到金属离子。这种光催化还原可以通过化学吸附进行，改性二氧化钛表面金属离子的还原和解吸过程，顺序和重复。在这里，甲醇被用作人工电子供体。这些混合光催化剂可重复使用多次而不会降低效率，同时 TiO2@His NPs 的还原率最高。因此，用氨基酸修饰的 TiO2 可以通过廉价的方法还原金属离子，具有高性能、高活性、可重复使用、易于制备、易于分离、环境友好和反应时间短等优点。