Mesoporous hybrid materials containing inorganic and organic functional groups are relevant for advanced applications in separation, sorption or heterogeneous catalysis. The possibility of combining materials with high surface area and tailorable mesopore size with a mixed oxide framework and organic functions open the gate to imitating complex biosystems such as enzyme active sites. One of the critical aspects towards a multiscale control of these complex materials is the understanding of the actual framework structure and the interplay of the framework ions and the organic functions, and how these features are related to the sol-gel preparation conditions. In this work, mesoporous hybrid organic-inorganic thin films (MHTF) based on a mixed silica-titania matrix containing 20% aminopropyl functions were prepared and thoroughly studied by X-ray absorption spectroscopy at both the Ti and Si K-edges, and by O1s and N1s X-ray photoelectron spectroscopy. This approach permitted us to simultaneously probe the changes in Si and Ti coordination, the linkages between the inorganic centers, and the availability of the amino functions along samples with varying Si:Ti ratio. We find substantial differences between the local structure of pure inorganic oxides and the hybrid materials. In the oxides, increasing the %Ti leads to an increase in octahedral Si sites and Ti-oxo clusters with shorter Ti-O bonds. In the hybrid materials, higher Ti coordination with longer bonds are observed, along with a prevalence of Si centers with distorted tetrahedral coordination. These findings suggest that aminopropyl building blocks act as a compatibilizer between Ti(IV) and Si(IV) centers, leading to a hybrid mixed phase with large silica-titania interface. This intermixing also influences the exposition of amino groups at the pore surface. These aspects are of importance in the design of high surface area adsorbents, permselective membranes or heterogeneous catalysts.

含有无机和有机官能团的介孔杂化材料与分离、吸附或多相催化等高级应用相关。将具有高表面积和可定制中孔尺寸的材料与混合氧化物框架和有机功能相结合的可能性为模仿复杂的生物系统（如酶活性位点）打开了大门。对这些复杂材料进行多尺度控制的关键方面之一是了解实际骨架结构和骨架离子与有机功能的相互作用，以及这些特征如何与溶胶-凝胶制备条件相关。在这项工作中，制备了基于含有 20% 氨基丙基官能团的二氧化硅-二氧化钛混合基质的介孔杂化有机-无机薄膜 (MHTF)，并通过 X 射线吸收光谱在 Ti 和 Si K 边缘以及 O1s 和 N1s X 进行了深入研究射线光电子能谱。这种方法使我们能够同时探测 Si 和 Ti 配位的变化、无机中心之间的联系以及氨基官能团在不同 Si:Ti 比的样品中的可用性。我们发现纯无机氧化物和杂化材料的局部结构之间存在显着差异。在氧化物中，增加 %Ti 导致八面体 Si 位点和具有较短 Ti-O 键的 Ti-氧簇增加。在混合材料中，观察到更高的 Ti 配位和更长的键，以及四面体配位扭曲的硅中心的普遍存在。这些发现表明氨基丙基结构单元作为 Ti(IV) 和 Si(IV) 中心之间的增容剂，导致具有大二氧化硅-二氧化钛界面的混合相。这种混合也影响氨基在孔表面的暴露。这些方面在设计高表面积吸附剂、选择性渗透膜或多相催化剂时很重要。