## 1 Introduction  
Heterostructures of different dimensionality have been investigated in the past because of their novel properties and challenging applications, including clean energy and new energy-related technologies, photocatalysis [1, 2], electrocatalysis [3], solar cells [4], energy conversion and storage [1, 5], up to research studies in biomedical fields [6, 7, 8]. In particular, since the discovery of graphene, 2D materials have attracted considerable attention due to their unique physical and chemical properties. Because of this, many efforts have been focused on the combination of two-dimensional layered materials (2 DLMs) with zero-dimensional ones (0D), such as plasmonic nanoparticles and quantum dots, and with mono-dimensional (1D) nanostructures, such as nanowires and nanoribbons, thus introducing a new way of nanoscale material integration and enabling the development of many extraordinary electronic devices. In this regard, 2D\(-\)2D van der Waals heterostructures made of distinct 2 DLMs and superlattices [8] play a considerable role in controlling and manipulating the generation, confinement, and transport of charge carriers, excitons, photons, and phonons within the atomic interfaces, thus giving chances for the design of unique and challenging devices [9, 10, 11]. Besides graphene-like and, in general, nanocarbon materials, families of semiconducting inorganic systems, such as nanostructured transition metal dichalcogenides (TMDs,i.e., MoS\({}_{2}\), WS\({}_{2}\)) and oxides (i.e., TiO\({}_{2}\), perovskites) [12; 13], are attractive candidates for heterostructures and hybrid combinations. Notice that each layer within two-dimensional layered materials (2 DLMs) consists of a covalently bonded, dangling-bond-free lattice, which provides the in-plane stability of 2D crystals, whereas relatively weak, van-der-Waals-like interactions are able to keep the neighboring layers together [14; 15]. This makes it feasible to isolate, mix, and match highly different atomic layers to create a wide range of van der Waals heterostructures (vdWHs) without the constraints of lattice matching and processing compatibility, in a sequence with one-atom-plane precision [15; 16; 17]. In this context, a large amount of MoS\({}_{2}\)/TiO\({}_{2}\)-based heterostructures with higher performance with respect to the individual MoS\({}_{2}\) and TiO\({}_{2}\)-based materials have been obtained [18; 19]. As a matter of fact, MoS\({}_{2}\) has been considered of great interest to perform MoS\({}_{2}\)/TiO\({}_{2}\) hybrid composites, due to its absorption in the UV\(-\)visible range, and then its ability to increase the visible light absorption of TiO\({}_{2}\)-based systems [20; 21]. However, TiO\({}_{2}\), despite being an excellent photocatalyst, is known to absorb only a small portion of the solar spectrum in the UV region (3% of the sunlight spectrum) [22]. Therefore, in order to exploit new and advanced applications, the relationship between the structure and properties in MoS\({}_{2}\)/TiO\({}_{2}\)-based composites has to be investigated. Concerning this point, lattice mismatch--that is, different lattice constants and atomic arrangements between MoS\({}_{2}\) and TiO\({}_{2}\)--causes TiO\({}_{2}\) particles to agglomerate, thus achieving poor interfacial contact of the TiO\({}_{2}\) particles with the MoS\({}_{2}\) layered material. As it is known that the interface plays a key role in charge carrier separation and migration [23], many efforts have been devoted to grow 2D MoS\({}_{2}\) nanosheets on the most exposed TiO\({}_{2}\) facets as substrates, which provide a larger contact specific surface areas for charge carrier transfers [5]. In particular, 2D anatase TiO\({}_{2}\) nanosheets with exposed [001] facets [24] have especially attracted great interest in the nucleation and growth of MoS\({}_{2}\) nanosheets [8; 25].