In this study, Ag-doped mesoporous TiO₂ powder was prepared via a sol–gel route with Pluronic P123 as template and then was modified with zinc(II) tetrakis(4-carboxyphenyl)porphyrin. The catalysts were characterized by X-ray diffraction, diffuse reflectance spectroscopy, Fourier transform infrared (FT-IR), scanning electron microscopy, N₂ sorption experiments (BET), X-ray fluorescence analysis, and inductively coupled plasma spectroscopy. The photocatalytic activities of Ag-doped mesoporous TiO₂ and Zn-TCPP/Ag-doped mesoporous TiO₂ were evaluated using methylene blue and p-nitrophenol as pollutant compounds under UV and visible light irradiation. The results show that Zn-TCPP/Ag-doped mesoporous TiO₂ have higher activity than Ag-doped mesoporous TiO₂ under visible light irradiation, but its activity is lower under UV light irradiation.

In this study, zinc oxide and silver and copper-doped zinc oxide nanorods were synthesized by a simple template-free precipitation technique. In addition, meso-tetrakis-(4-sulfonatophenyl) porphyrin (TPPS4) was prepared and immobilized on ZnO nanorods (TPPS/ZnO). The synthesized photocatalysts were characterized by various techniques such as X-ray powder diffraction, scanning electron microscopy, UV-visible spectroscopy, diffuse reflectance spectroscopy, and Fourier transform Infrared spectroscopy. The potential of the obtained photocatalysts in the degradation of methylene blue was investigated under UV and visible light irradiation. The results revealed that the photocatalytic activity of TPPS/ZnO was higher than those of the pure ZnO and doped ZnO under visible light irradiation.

The NiO nanoparticles, nanorods, and nanoworms were synthesized by a hydrothermal reaction of NiCl₂ with NaC₂O₄, as a precipitation agent, and H₂O in the presence of ethylene glycol at different temperatures (100, 140, 180, and 220°C) for 12 h. It was observed that by changing the hydrothermal temperature, one can effectively control the size and morphology of NiO nanostructures. The nanostructures were characterized by X-ray diffraction, Fourier transform infrared, scanning electron microscopy, transmission electron microscopy, and diffuse reflectance spectroscopy. Photocatalytic activity of nanostructures against 4-nitrophenol was investigated under ultraviolet and visible light irradiation. The results indicated that photocatalytic activity of NiO nanoworms synthesized at 220°C was higher than that of the other prepared NiO nanostructures.