典型稀土元素修饰的二氧化钛光催化性能研究进展

Research Progress on Photocatalytic Properties of TiO_(2) Modified with Typical Rare Earth Elements

TiO_(2)的禁带宽度较宽,其带隙值一般为3.0~3.2 eV,将其光激发区域限制在紫外光区域,大范围的可见光甚至近红外光区的光子都没有被利用起来.此外,TiO_(2)较高的电子—空穴对重组率也导致了其具有活性的光生载流子寿命降低,限制了TiO_(2)作为光催化剂的效率.为了使这些问题得到妥善解决,可采用稀土元素(镧系元素)改善TiO_(2)表面形貌、晶体类型、光学特性和光催化性能.综述了近年来被用作TiO_(2)修饰改性的热门镧系元素的研究,重点阐述了镧系元素如何修饰改性TiO_(2),使其性能提升远超过纯TiO_(2),并介绍了镧系元素-TiO_(2)在光催化和电子电器方面的应用.稀土元素的修饰可通过减小带隙,将TiO_(2)工作波长从紫外光区移到可见光区域,抑制锐钛矿相到金红石相的转变,以及减弱光生电子对的重组效率等方式提高TiO_(2)的光催化效率.

TiO_(2) has a wide band gap,and its band gap value is generally 3.0~3.2 eV,which limits its photoexcitation region to the ultraviolet region,and a large range of visible light and even near-infrared photons are not used.In addition,the high electron-hole pair recombination rate of TiO_(2) also leads to the reduced lifetime of its active photogenerated carriers,which limits the efficiency of TiO_(2) as a photocatalyst.In order to solve these problems properly,the use of rare earth elements(lanthanides)to improve the surface morphology,crystal type,optical properties and photocatalytic performance of TiO_(2) have been studied.This paper reviews the recent studies on the hot lanthanide elements used as TiO_(2) modification.It focuses on how Ln elements modify TiO_(2) to improve its performance far beyond that of pure TiO_(2),and focuses on the application of Ln-TiO_(2) in photocatalysis,electronics and electrical appliances.The modification of rare earth elements can improve the photocatalytic efficiency of TiO_(2) by reducing the band gap,shifting the working wavelength of TiO_(2) from ultraviolet to visible region,inhibiting the transition from anatase phase to rutile phase,and weakening the recombination efficiency of photogenerated electron pairs.