Series of Sc/V co-doped rutile TiO₂ with different Sc/V ratio was synthesized. Samples were characterized by XRD, SEM, XPS, BET, EPR, diffuse reflectance spectroscopy and Kelvin probe methods. EPR spectroscopy reveals a simultaneous increase of V⁴⁺ and Ti³⁺ as vanadium content grows. At the same time, an increase of vanadium concentration in co-doped samples results in stronger absorption in visible light range. However, a photocatalytic activity dependence on the co-dopant ratio demonstrates “volcano” plot behavior with maximum at 75/25 Sc/V ratio, while the work function dependence on Sc/V ratio demonstrates a negative correlation with photocatalytic activity resulting in a minimal value of work function at the same optimal ratio of co-dopant content. The analysis of the experimental results infers that alteration of Sc/V co-doping ratio leads to redistribution between shallow traps, which are not effective in charge carrier recombination, and deep traps, which act as effective recombination centers, with maximal shallow traps concentration corresponding to the optimal Sc/V ratio equal to 75/25, yielding the lowest recombination efficiency and therefore, the highest photocatalytic activity. Redistribution of defect states induced by co-doping should be distinguished as a primary factor of alteration of photocatalytic activity in co-doped TiO₂. Presented results demonstrate that photoactivity of co-doped titania cannot be considered as result of either independent action of dopants or their additive effect.

合成了一系列不同Sc / V比的Sc / V共掺杂金红石型TiO ₂。通过XRD，SEM，XPS，BET，EPR，漫反射光谱和开尔文探针法对样品进行表征。EPR光谱显示V ⁴⁺和Ti ³⁺同时增加随着钒含量的增长。同时，共掺杂样品中钒浓度的增加导致在可见光范围内的吸收更强。但是，光催化活性对共掺杂比的依赖性表现出“火山”情节行为，在75/25 Sc / V比下具有最大值，而功函数对Sc / V比率的依赖性则与光催化活性呈负相关关系，从而导致最小在相同最佳比例的共掺杂物含量下的功函数的值。对实验结果的分析表明，Sc / V共掺杂比的改变会导致对电荷载流子重组无效的浅陷阱和充当有效重组中心的深陷阱之间的重新分布，最大浅陷阱浓度对应达到最佳Sc / V比等于75/25，产生最低的重组效率，因此具有最高的光催化活性。由共掺杂引起的缺陷态的重新分布应作为共掺杂TiO中光催化活性改变的主要因素加以区分₂。提出的结果表明，不能将共掺杂的二氧化钛的光活性视为掺杂剂的独立作用或它们的加和作用的结果。