A useful nanophotocatalyst (La, S-TiO2) was prepared by a sol-gel method and characterized by UV–vis diffuse reflectance spectroscopy (DRS), X-ray diffraction (XRD), photoluminescence emission spectroscopy (PL) and scanning electron microscopy (FESEM). The results showed that the La, S-TiO2, which calcined at 550oC, contained only anatase phase and its crystal size was 23 nm. In addition, the FESEM analysis indicates that the La, S-TiO2 nano particles with diameter of 20 to 25 nm could have a good dispersion in solution. In order to evaluate of activity of the modified synthesized photocatalyst (La, S-TiO2), comparison between modified synthesized TiO2 (La, S-TiO2) and pure synthesized TiO2 for degradation of Methyl Orange was investigated. It was found that the modified synthesized photocatalysis (La, S-TiO2) has much higher photocatalytic activity than undoped TiO2 for the degradation of contamination.

S-doped and baremesoporous TiO2 were prepared using titaniumtetraisopropoxideand thiocarbamide as raw materials. Prepared materials were characterized by means of fourier transform infrared spectroscopy FT-IR, thermogravimetry-differential scanning calorimetry (TG-DSC), X-ray diffraction (XRD), UV-Vis absorption spectroscopy, Brunauer-Emmett-Teller (BET) specific surface area and Barrett–Joyner-Halenda (BJH) pore size distribution analyses, scanning electron microscopy (SEM) and Energy-dispersive X-ray spectroscopy (EDX). The band gap of S-doped was estimated from UV-Vis spectroscopy data to be 2.8 eV. The specific surface area of S-doped TiO2 nanoparticles obtained via the BET method, calculated to be 181.3 m2/g and its pore size distribution curve revealed that the average diameter of the pores is 12.3 nm using BJH method. Photocatalytic efficiency of synthesized S-doped mesoporous TiO2 was tested for degradation of Congoredazo dye under ultraviolet and visible lights. The results revealed that the S-doped mesoporous TiO2 is the most effective under visible lightin comparison withbareone.

ZnO/Fe2O3/Zeolite nanophotocatalyst was synthesized by sol-gel method, and its performance in degradation of ENR, as one of the most commonly used veterinary antibiotics, is evaluated. The synthesized nanophotocatalyst is characterized by XRD, XRF, FT-IR, FE-SEM, EDX, and BET analyses. According to XRD, FT-IR, and EDX, presence of ZnO and Fe2O3 on the zeolite surface is confirmed. Based on XRF results, the optimal molar value of Fe3+/ZnO in the synthesized nanophotocatalyst is obtained as 0. 06. The FE-SEM results confirm the deposition of ZnO/Fe2O3 on the zeolite surface and indicate the approximate size of the photocatalyst particles as 48 nm. According to BET results, the specific surface area and pore volume for the synthesized nanophotocatalyst are obtained as 280. 16 m2/g and 0. 35 cm3/g, respectively. The simultaneous effects of operational factors, including the concentration of pollutant (150-450 mg/l), initial pH of the solution (5-9), and H2O2 concentration (50-200 mg/L) are examined on the ENR degradation efficiency via RSM. The results demonstrate that ENR concentration, pH, and H2O2 concentration have significant impacts on the ENR degradation efficiency in turn. According to the experimental results under optimal conditions (pH, contaminant concentration, and H2O2 concentration: 9, 500 mg/l, and 90 mg/l, respectively), the ENR degradation efficiency is 97. 4%. This study suggests that the synthesized nanophotocatalyst has an acceptable efficiency to degrade a non-biodegradable contaminant.

ZnO and SnO2-doped ZnO nanoparticles were prepared by a sol–gel method for the first time. X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used to characterize the ZnO and SnO2-doped ZnO samples. Advanced oxidation processes (AOPs) have proved very effective in treatment of the various hazardous organic pollutants such as surfactants and pharmaceuticals in water. The photocatalytic degradation of drug phenylephrine hydrochloride (PHE) was studied as model organic pollutant. Under UV exposure the process was investigated with ZnO and SnO2-doped ZnO. The degradation was studied under different conditions including irradiation time, pH, catalyst concentration, phenylephrine hydrochloride concentration and potassium peroxydisulfate as an oxidant. The experimental results indicated that maximum degradation (99.4±1.0%) of drug occurred with SnO2-doped ZnO catalyst. The results demonstrated that photodegradation efficiency of SnO2-doped ZnO was significantly higher than that of undoped ZnO.