Sharif Digital Repository

Photocatalysis is well-known as an effective tool for the removal of pollutants but its eco-friendly aspect has not been well explored in the literature. In this study, we prepared an ultraviolet-active photocatalyst by the growth of cerium oxide/sulfide nanoparticles in the zeolite channels via a facile coprecipitation method. The photocatalyst was comprehensively characterized by different analysis methods and showed good activity toward removal of acetamiprid, ACP, a commonly used insecticide. As the main focus of the current work, an in vivo bioassay was carried out to investigate the acute toxicity of the contaminant solutions before and after photoreaction. Accordingly, acetamiprid and... 

Tetracyclines (TCs) are a large family of broad-spectrum antibiotics with one of the highest aquatic persistence after release from humans and animals. Hence, TCs are known to generate antibiotic resistance along with estrogenic and other toxic effects in non-target organisms. Unfortunately, the detection and removal of TCs from aqueous matrices remain challenging. For this purpose, we review metal–organic frameworks (MOFs), which have emerged as effective alternatives, given their photocatalytic and adsorptive capabilities. MOFs exhibit large interactive surface area and tunable structure and pore size for fast mass transfer and strong host–guest interactions. Herein, these and other topics... 

Zeolite-based Ag/AgBr and Ag/AgBr/TiO2 photocatalysts were prepared by sol–gel and deposition methods and were characterized. Their photocatalytic activities were evaluated by inactivation of Escherichia (E.) coli and the photodegradation of Acid Blue 92 and potassium permanganate. The composites containing Ag/AgBr showed the antibacterial activity in the dark by releasing Ag+ ions into the medium. The results for inactivation of E. coli indicated that Ag/AgBr/TiO2 modified photocatalyst had better antibacterial activity than Ag/AgBr/zeolite, while zeolite and TiO2/zeolite did not show any antibacterial activity under visible light and dark conditions. Photodecolarization rate was affected... 

In this study, the effect of adding 5–12.5 wt% CuO to TiO2 on photocatalytic properties of the nano-composite TiO2/CuO was investigated. The products were characterized by X-ray diffractometer, SEM, Brunauer–Emmett–Teller (BET), and DRS. BET-specific surface area of the TiO2/CuO composites was lower than that of the pure TiO2. Incorporation of CuO into TiO2 shifted absorption spectra to the visible region. As the CuO content increased from 0 to 12.5%, a clear decrease in optical band gap from 2.95 to 2.30 eV was observed. The photocatalytic performance was determined by methyl orange degradation and cyanide photo-oxidation under ultraviolet irradiation. However, the excessive incorporation... 

BiOCl was synthesized using bismuth nitrate pentahydrate and sodium chloride via ball milling for 15 (B15), 30 (B30), and 60 (B60) min. Scanning electron microscopy studies revealed the isolated nanoplate morphology for B15, an aggregated structure composed of nanoplates for B30, and a special three-dimensional morphology for B60. The X-ray diffraction patterns showed the purity and crystallinity of the products improved by increasing the milling time. Fourier transform infrared spectroscopy, photoluminescence spectroscopy, and nitrogen adsorption-desorption analysis using the Brunauer-Emmett-Teller technique were also used to study the products. Diffuse reflectance spectroscopy studies... 

We report the nanoporous Ag2O based on the copper terephthalate metal–organic frameworks (Ag2O/MOF) photocatalyst. Ag2O/MOF nanostructure was formed via oxygen treatment of Ag/MOF nanoparticles. The resulting Ag2O/MOF photocatalysts were characterised by various techniques. Results showed that the synthesised Ag2O/MOF nanocomposite exhibited dramatic separation of photoinduced electron/hole and excellent photodegradation activity under visible light irradiation. The degradation rate of acid blue 92 using Ag2O/MOF nanocomposite is found to be higher than that using pure MOF and Ag/MOF. It was divulged that the photodegradation rate is increased by oxygen treatment of Ag in Ag/MOF structure.... 

The oil-based compounds are widely used in modern human life, and the accidental release or leakage of these compounds is led to water and soil pollution and creates many problems for the environment. The purpose of this study was to determine the efficiency of photo-catalytic degradation of pyrene using Fe-doped TiO2 in the presence of UV. This experimental study was carried out at laboratory scale in a 2 L pilot reactor. The nanoparticle was synthesized by the sol-gel method. Pyrene degradation was investigated under different conditions of pH, reaction time, nanoparticle concentration and pollutant concentration. For the statistical analysis, SPSS V.16 software and one-way analysis of... 

The nanocomposite of g-C 3 N 4 supported by MIL-88A has been prepared via a facile hydrothermal method. The photocatalytic performance of as-prepared composite (MIL-88A/g-C 3 N 4 ) was examined by the degradation of the Methylene Blue (MB) solution under visible light. The characterization test illustrated that the MIL-88A particles were successfully dispersed on the surface of g-C 3 N 4 structure. Photoactivity results demonstrated that the MIL-88A/g-C 3 N 4 /H 2 O 2 exhibited dramatically visible light photocatalytic performance. Hydroxyl radicals ([rad]OH) are generated by dissociation of H 2 O 2 under visible irradiation can remarkably enhance the degradation rate of MB molecules.... 

The aim of the present study was to evaluate the photocatalytic degradation of anthracene using Fe-doped TiO2 nanoparticles in the presence of UV. The structure and morphology of Fe-doped TiO2 nanoparticles were studied by X-ray diffraction, scanning electron microscopy, and energy-dispersive X-ray spectroscopy. The applied nanoparticles were synthesized by the sol–gel method. The effect of influential parameters on the degradation of anthracene, including pH, time, nanopar-ticles dosage, and the concentration of anthracene was studied. Using the UV/Fe-doped TiO2 system, the optimum experimental values were obtained to be as follows: pH = 7, contact time = 60 min, anthracene concentration =... 

Herein, NiO and Co2 O3, NiCo2 O4, and NiCo2 O4 /multi-walled carbon nanotubes nanocomposite were synthesized by the hydrothermal method and characterized by scanning electron micros-copy, energy dispersive spectroscopy, and X-ray diffraction. The photocatalytic activity of the synthesized materials was evaluated by Reactive Red 120 dye degradation. The photocatalytic activity of NiO and Co3 O4 was enhanced not only by the formation of NiCo2 O4, but also by its interaction with the functionalized multiwall carbon nanotubes support. The response surface methodology (RSM) was used to obtain the optimum parameters, including catalyst dosage, initial dye concen-tration, and pH on the dye... 

Eight eco-friendly, and magnetically-separable heterogeneous photocatalysts including five Au nanoparticles (NPs) modified magnetic TiO2@Fe3O4 NPs and three Ag-Au bi-plasmonic NPs-decorated TiO2@Fe3O4 NPs with enhanced photocatalytic performance under visible light were synthesized and used for photodegradation of methyl orange (MO) as a model pollutant in textile wastewater samples. The photocatalytic activity was assessed using two radiation sources namely, an intense linear 532-nm laser and a continuous solar-simulated xenon lamp. Compared to the TiO2 alone, the prepared photocatalysts revealed efficient photocatalytic activity in visible region due to the presence of two localized... 

Branched hierarchical zinc oxide nanowires (BH-ZnO NWs) were fabricated successfully by a facile and rapid synthesis using two-step growth process. Initially, ZnO NWs have been prepared by anodizing zinc foil at room temperature and followed by annealing treatment. Then, the BH- ZnO NWs were grown on the ZnO NWs by a solution based method at very low temperature (31 oC). The BH- ZnO NWs with different aspect ratio were obtained by varying reaction time (0.5, 2, 5, 10 h). Photocatalytic activity of the samples was studied under both UV and visible light. The results indicated that the optimized BH-ZnO NWs (5 h) as a photocatalyst exhibited the highest photoactivity with about 3 times higher... 

The photocatalytic degradiation of phenol by nanoTiO2 particles coated on perlite as a new composite nano-catalyst was investigated. Titanium dioxide (Degussa P-25) was immobilized on three different supports (perlite granules, glass plates and steel fiber) by a very simple and inexpensive method. Perlite granules have a porosity of more than 95%, which allows them to stay afloat on water surface. This gives the medium a unique characteristic from the processing point of view, which enables it to get wetted with the polluted solution without requiring any pumping and simultaneously be exposed to the radiation source when coated with the photocatalyst. The photocatalytic activity of prepared... 

The degradation of methyl tert-butyl ether (MTBE) was investigated in the aqueous solution of coated ZnO onto magnetite nanoparticale based on an advanced photocatalytic oxidation process. The photocatalysts were synthesized by coating of ZnO onto magnetite using precipitation method. The sample was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and vibration sample magnetometer (VSM). Besides, specific surface area was also determined by BET method. The four effective factors including pH of the reaction mixture, Fe3O4/ZnO magnetic nanoparticles concentration, initial MTBE concentration and molar ratio of [H2O2]/ [MTBE] were optimized using response surface... 

In this research, anatase TiO2 nano-particles were electrophoretically deposited on the FTO glass. This investigation was focused on the self-cleaning property of TiO2 coatings and the effects of different parameters on this characteristic such as: applied voltages during electrophoretic depositions and durations of UV irradiation. Electrophoretic depositions of suspensions were performed in different voltages of 10, 30 and 60 V (for 10 s) at room temperature. TiO2 coatings were sintered in 450oC for 1 hr. The phase transformation of TiO2 films was considered using XRD. Morphology, average particle size and the thickness of TiO2 films was analyzed using FESEM microscope. The photocatalytic... 

The development of graphene-based nanocomposites is currently the issue of enormous research interest. Recent advancements have exhibited that semiconductor/graphene nanocomposites can be purposed as a promising new category of catalysts for the heterogeneous photocatalytic treatment of wastewaters. Since semiconductor/graphene nanocomposites have been found efficient in degradation of organic pollutants, photodegradation of phenol and phenolic compounds as hazardous contaminants in aqueous solution has been most widely investigated by these aforementioned nanocomposites. In the present review, after introduction on the properties and the different synthesis methods of semiconductor/graphene... 

Abstract: Photocatalysis using semiconductors has emerged as a promising wastewater treatment process to overcome the major challenges faced by conventional technologies. The advantages of ZnO nanomaterials over other semiconductors, and their structure-dependent properties, make them important building blocks in nanotechnology as multifunctional materials. Moreover, it has been confirmed that ZnO nanomaterials can exhibit high performance in photodegradation of organic dyes for treatment of industrial effluent. The wurtzite structure of ZnO contains polar and nonpolar planes; the low surface energy and thermodynamic stability of the nonpolar planes enable formation of one-dimensional (1D)... 

In this study, aluminum titanate (Al2TiO5)-based nanostructure with the outstanding photocatalytic performance was prepared via the simple citrate sol-gel method. The effects of thee operational variables such as pH, temperature, catalyst dosage, and initial dye concentration on the photodegradation efficiency of methylene blue (MB) were explored in some details. The results showed that compared to TiO2, AT benefits a superior photocatalytic activity due to its narrow band gap (2.88 eV) and low recombination rate of charge carriers. Increasing the wastewater temperature from 25 to 60 °C can improve the degradation percent from 22.15 to 52%. Based on the thermokinetic calculations, the... 

Recently, aluminum titanate (Al2TiO5)-based nanostructures have been proved to serve as an efficient photocatalytic material with satisfactory photodegradation capacity. In this study, the citrate sol–gel method was used to synthesize these nanostructures and inspect the significant impacts of nitrogen-doping-originated crystalline defects on their photocatalytic performance in some details for the first time. The results indicated that the penetration of nitrogen atoms into AT crystal lattice, depending on the nitriding time and temperature, can induce a great deal of the residual stress and result in propagating the existing cracks and breaking down the particles. The XPS and FTIR results...