The TiO₂ modified by monometallic (Au-TiO₂, Pt-TiO₂) and bimetallic (Pt/Au-TiO₂) NPs have been synthesized by a simple sol-gel method. The optimal dosage of individual components in Pt/Au composition on photocatalytic activity has been systematically investigated. The obtained photocatalysts were thoroughly characterized by BET surface area measurements, UV–vis diffuse-reflectance spectroscopy (DRS), X-ray diffraction analysis (XRD), scanning transmission microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). The photocatalytic activity under visible light (λ > 420 nm and λ > 455 nm) has been estimated in phenol degradation reaction in an aqueous phase. The best photocatalytic activity has been observed for −mono (0.5)Pt_TiO₂ and bimetallic (0.5)Pt/(0.5)Au_TiO₂ samples with an optimum platinum content. The Pt/Au_TiO₂ radical formation mechanism was systematically investigated with the selected scavenger for the degradation process under vis light irradiation. The formation of O₂⁻ with (0.5)Pt/(0.5)Au_TiO₂ was established from the high inhibition of phenol degradation. Based on the XPS analysis it was observed that the greater photoactivity of bimetallic sample (0.5)Pt/(0.5)Au_TiO₂ could result from a relatively higher content of platinum compared to gold on the surface layer. It must be noted that only platinum takes a significant part in Pt/Au composites on the photoactivity. Furthermore, in this work we present a linear relationship between the crystal size of TiO₂ and the reaction rate of Au-TiO₂, Pt-TiO₂ and Pt/Au-TiO₂.

在TiO ₂由单金属（金-二氧化钛改性₂和Pt-的TiO ₂）和双金属（铂/金-TIO ₂）纳米粒子已经通过一个简单的溶胶-凝胶法合成。系统地研究了Pt / Au组合物中各个组分对光催化活性的最佳剂量。所获得的光催化剂通过BET表面积测量，紫外可见漫反射光谱（DRS），X射线衍射分析（XRD），扫描透射显微镜（TEM）和X射线光电子能谱（XPS）进行了全面表征。在水相中的苯酚降解反应中，已经估计了在可见光（λ> 420 nm和λ> 455 nm）下的光催化活性。已观察到对-mono（0.5）Pt_TiO的最佳光催化活性₂和具有最佳铂含量的双金属（0.5）Pt /（0.5）Au_TiO ₂样品。利用选定的清除剂，对可见光照射下的降解过程，系统地研究了Pt / Au_TiO ₂自由基的形成机理。的O的形成₂ ^-与（0.5）的Pt /（0.5）Au_TiO ₂从高抑制酚降解的建立。根据XPS分析，观察到双金属样品（0.5）Pt /（0.5）Au_TiO _2的光活性更高这可能是由于表层的铂含量高于金含量。必须注意的是，在光活性方面，只有铂在Pt / Au复合材料中占重要地位。此外，在这项工作中，我们提出了TiO ₂的晶体尺寸与Au-TiO ₂，Pt-TiO ₂和Pt / Au-TiO ₂的反应速率之间的线性关系。