TiO2 is the most extensively explored material for photocatalysis because it is non-toxic, inexpensive, and (photo) chemically stable. TiO2 is frequently employed in the form of nanostructures such as nanoparticle and anodic TiO2 nanotubes (TiNTs) layers, which provide a high surface area for photocatalytic reactions. However, under electroless conditions (when no bias voltage is applied), TiO2 is not sufficiently efficient in photocatalytic hydrogen generation in the absence of a proper co-catalyst. Mainly noble metals such as Au, Pt, and Rh are used as co-catalysts and can provide high efficiency in electroless photocatalytic H2 evolution; however, they are all rare and expensive. Therefore, the focus of this thesis lies on the effective use of noble metals on the TiO2 nanostructured surfaces for photocatalysis applications. Firstly, we study anodic oxidation of metastable titanium and gold binary alloy substrates that are produced by Ti and Au co-sputtering. Using metastable titanium and gold binary alloy layers for anodization of TiNTs results in a controlled loading and significantly higher density of gold nanoparticles than using standard cast alloys. Photocatalytic hydrogen generation from optimized gold nanoparticle density delivers a 15 times higher photocatalytic hydrogen generation activity compared to the best one attained by conventional cast alloys. In the second section, a technique for selective loading of TiNTs with gold nanoparticles is investigated. Titanium and gold co-sputtering was performed to fabricate Ti-Au binary alloy layers that contain compositional gradients through their thickness. When these sputtered layers are anodized under optimized conditions, we can form gold loaded TiNTs where the gold nanoparticle placement and density differ according to the gold compositional profile across alloy substrates. The results suggest that gold nanoparticles placement significantly enhanced the photocatalytic hydrogen generation of the Au-TiNT layers. We show that when fabricating gold decorated TiNTs, the use of Ti-Au sputtered alloy with an appropriate gold compositional gradient can result in higher hydrogen generation rates compared to TiNTs classically grown on a homogenous sputtered alloy. As a side effect, proper placement of the co-catalyst nanoparticles provides a strategy for the efficient loading of noble metals without suppressing the hydrogen generation activity. In the third part, we fabricate intrinsically copper doped TiNTs by anodic oxidation of titanium-copper binary alloys. We show that up to 1.5 at.% copper concentration in the Ti-Cu alloy, cupric doped TiNTs can be grown. The cupric ion can be converted to metallic copper nanoparticles on TiNT surfaces under UV illumination, which results in uniformly top surface copper decorated TiNTs. The top surface copper decorated TiNTs provide an enhanced photocatalytic hydrogen generation activity in comparison to pristine TiNTs. Light-induced conversion of the intrinsic copper doping to metallic Cu nanoparticles is the key for stable photocatalytic hydrogen generation in the investigated system. In the fourth section, we investigate a straightforward method for TiNT decoration with rhodium nanonetworks, which represent a co-catalytic feature in photocatalysis hydrogen generation on the TiO2 surface. Initially, a dealloying performed on titanium- rhodium binary alloy in Kroll solution results in a decorated surface with a rhodium nanonetwork with adjustable loading and geometry. The preliminary dealloying followed by anodization of the samples, rhodium doped TiNTs, is achieved while the rhodium nanonetwork firmly covers the tube mouths. According to X-ray photoelectron spectroscopy (XPS) results, these rhodium oxide nanonetworks are converted to metallic rhodium under ultra-violet light irradiation. TiNTs carrying a rhodium nanonetwork provide a 5-times higher H2 generation activity compared to conventional rhodium sputtered TiNTs (the same loading), and present approximately 200 times higher hydrogen evolution than non-decorated TiNTs. In the last section, we focused on single-atom (SA) catalysts as a new and advance topic in the catalysis field due to the extreme improvement in catalytic activity and selectivity of such reactions. We investigate engineering of an atomic-scale defect to control and form traps for platinum single-atom sites that then act as co-catalytic centers on TiO2 surfaces for photocatalytic H2 generation. To investigate this concept, 7 nm thin sputtered polycrystalline TiO2 layers were used as a model photocatalyst, and the behavior is studied in comparison to the more often used (001) exposed anatase sheets (flakes grown by hydrothermal synthesis). To form stable single-atom platinum co-catalyst centers, the sputtered TiO2 layers were reduced in various conditions in Ar/H2 (which leads to diverse but distinct Ti3+-Ov surface defects), followed by dipping in a dilute H2PtCl6 aqueous solution. Annular dark-field imaging confirms that on both substrates, defects for SA platinum trapping can be obtained, however, only on the thin film anatase, the degree of reduction treatment gives us a successful control over the density of SA sites. We show that an optimized platinum SA decoration can increase the specific photocatalytic activity of a sputtered TiO2 sample by 150 times compared to a typical Pt nanoparticle decorated TiO2 surface. The result from annular dark-field imaging, EPR, and XPS investigations prove the atomic nature of the platinum on TiO2. Notably, the density of relevant Ti3+-Ov surface-exposed defect centers can be tuned and, therefore, can be used to control the resulting density of platinum single-atom sites, which in turn play a critical role in the reactivity of the photocatalyst.