## 8 Porphyniroids and Titanium(IV) Oxide-Based Hybrid Materials and Their Photocatalytic Activity
Quantum efficiency was lower for TiO\({}_{2}\)-MnPp systems (0.58-0.63) than for bare TiO\({}_{2}\) (0.79). In addition to the above-mentioned results, these TiO\({}_{2}\)-Pp systems presented high thermal and photo-stability. The porphyrinoids did not reveal any kind of self-degradation even after 5-7 h of irradiation in the same conditions as in the photoreactivity experiments [163]. In the study lately performed by our group, we have examined the photocatalytic properties of hybrid nanomaterials based on 5 nm and 15 nm anatase TiO\({}_{2}\) and metallopthalocyanines (Cu(II) and Zn(II)) [162]. Taking into consideration that the phthalocyanines did not have any functional groups that would allow for covalent binding to the surface of TiO\({}_{2}\), we suspected that the mode of deposition on the surface was based on the adsorption and weak forces such as hydrogen bonding. These hybrid materials were used for the degradation of ibuprofen in an aqueous solution under UV (365 nm) and red light (665 nm), separately. Our findings show that TiO\({}_{2}\)-CuPc achieved similar degradation efficiency (around 90% decrease in initial concentration after 6 h of irradiation) as pure anatase when irradiated with UV light, proving that the copper(II) phthalocyanine did not impair the catalyst's photoactivity. Interestingly, TiO\({}_{2}\)-ZnPc presented lower degradation rates (50% decrease after 6 h). ZnPc is known to have good singlet oxygen quantum yields. Therefore, we suspected that the energy absorbed by the phthalocyanine after irradiation was internally converted by itself, leading to both ZnPc and TiO\({}_{2}\) producing separate ROS species that recombined with each other and were mutually, prematurely eliminated. This  
Figure 11: The applicability of porphyrinoids and titanium(IV) oxide-based hybrid materials as catalysts in the photodegradation studies of various pharmaceutically active ingredients. led to extinction of the ROS species and impairment of the photocatalytic process in the environment where TiO\({}_{2}\)-ZnPc was used. The importance of binding between porphyrinoids and titania was presented by [PERSON] et al., who prepared various hybrid materials based on anatase TiO\({}_{2}\) and porphyrins (Ps) with carboxyphenyl groups for photocatalytic applications [164]. Photocatalysts were used for the degradation of methylene blue under visible light produced by a 50 W halogen lamp. All of the tested hybrid materials showed higher photocatalytic activity than pure TiO\({}_{2}\). After 60 min of irradiation, methylene blue was almost entirely degraded in the aqueous medium with up to 95% decrease in the dye initial concentration, while pure TiO\({}_{2}\), at that time point, showed only a 55% decrease. Contrary to our findings, the authors stated that ZnPs used in their study showed better photocatalytic activity than other porphyrins, explaining the fact by better electron coupling of ZnPs with the conduction band of TiO\({}_{2}\). This could be explained by the fact that ZnPs in the study had anchoring groups in their periphery, allowing for covalent binding to the surface of TiO\({}_{2}\) and efficient energy transfer from the photosensitizer to TiO\({}_{2}\). The reaction environment is crucial for the progress of photocatalytic processes. In our latest study, metallic porphyrazines (Mg and Zn) functionalized with morpholinylethylsulfanyl moieties were used to functionalize P25 TiO\({}_{2}\). Novel hybrid material was subsequently applied in photocatalytic studies with active pharmaceuticals such as diclofenac sodium salt and ibuprofen, dissolved in organic solvents [165]. The employed functional groups promoted agglomeration of the hybrid nanoparticles by a large margin (the mean diameter increased over four times compared to pure P25). Initial photocatalytic oxidation activity was assessed with diphenylisobenzofuran (DPBF) in dimethylformamide (DMF) under red light irradiation (665 nm). The photocatalytic activity was assessed based on UV-Vis spectra measurements for DPBF over a period of 8 min.