جستجوی مقالات مرتبط با کلیدواژه "photocatalytic" در نشریات گروه "شیمی"

This study developed for synthesis of some novel photocatalytic nanocomposites from nano graphitic carbon nitride(g-C3N4), nano bismuth oxide (Bi2O3) and nano-graphene oxide (NGO) due to degradation of methylene blue dye as an organic pollutant in waste water. These synthesized novel ternary nanocomposites including BiC80/GO, BiC80/GO, BiC80/GO and BiC80/GO which characterized by FTIR, UV–Vis, XRD, PL, TGA, FESEM, and EDS to study of thermal stability, surface morphology, and purity of nanocomposites. The degradation efficiency (D%) for nano materials and novel ternary nanocomposites, under the visible light irradiation in a time period of 180 min was investigated in this work. The optimum conditions obtained for preparation of ternary nanocomposites BiC80/GO (20 mg), are 50 mg catalyst and 5 ppm dye concentration at 35 °C in pH 12.

The hybrid nano sized material ZnO-WO3 nanocomposite was synthesized utilizing as known hydrothermal method. The incorporation of WO3 NPs into the zinc oxide structure raised the porosity and surface area, besides a rise in the number of active sites and function of the composite, which can enhance the photo-catalytic method to remove tetracycline (TC) drug, according to structural analyzes utilizing SEM, XRD, and TEM. All experiment was performed utmost best condition concentration of TC drug of 20 mg/L, and solution pH 4.8, the results displayed that the phot-catalytic degradation raised with decreasing TC drug concentration (99.87 %-77.55 %) when concentration increased (10-50 mg/L) and photocatalytic degradation increased when the mass of ZnO-WO3 nanocomposite increase (58.43 % to 97.99 %). The photo-catalytic degradation method showed that after 60 min, it led to the Tc drug removal, and a degradation capacity of equal to 82.87 % was obtained utilizing zinc oxide nanoparticles, while the complete ZnO-WO3 NPs photo-catalytic method was found after 1 h of the photocatalytic method degradation capacity of up to 97.86%. Calculations of DFT approve that some properties, including Van der Waals force, electrostatic interaction, and hydrogen bonding, were the main steps for adsorption mechanisms in the synergistic interactions among TC drug and nano-composite surface.

In this study, BaGdxAlxCrxFe(12-3x)O19 (x = 0.0, 0.2, 0.4, 0.6, 0.8) hexagonal ferrites were synthesized by sol-gel combustion methods. The samples' X-ray diffraction pattern shows a hexagonal phase that was identified using JCPDS data (00-033-1340) and had hexagonal crystal symmetry in space group P63/MMC. On the FTIR spectrum of BaGdxAlxCrxFe(12-3x)O19, the bands at 431-605cm-1 correspond to the Fe-O stretching vibrations and prove the formation of nanohexagonal ferrites. Field emission electron microscopy (FESEM) pictures have represented the formation of hexagonal nanoparticles, but by increasing the dopants, which have less magnetic properties than iron (III) ions, the hexagonal structure can be seen well yet. A vibrating sample magnetometer (VSM) shows the Ms value of the barium hexaferrite (BHF) sample at approximately 63.76 emu/g, which is proportional to the predicted value for standard hexaferrites, and Hc at approximately 7000 Oe, confirming the magnetic hardness of the nanocomposite. The hysteresis diagrams show that the values of Ms and Hc decrease with increasing dopants. The degradability of methylene blue (MB) demonstrates that all samples have desirable photocatalytic properties in visible light. The degradability rates in all samples are 65%-99%. The results indicate that the degradability rate increases significantly as the dopant ions increase.

In this study, the prepared, characterization, and photo-catalytic performance of zinc oxide/activated carbon (ZnO/AC) nanocomposites prepared via hydrothermal process to be applied for advanced oxidative process (AOPs). The ZnO/AC nanocomposites was characterized via field emission scanning electron microscopes (FE-SEM), transmission electron microscopy (TEM) and energy dispersive X-ray analysis (EDX) analyses. Different parameters were utilized to achieve best conditions including, weight of nanocomposite, and concentration of Riboflavin drug. Likewise, the photo-degradation appear high efficiency and activity when reused 5 cycles and confirm results that this photo-catalyst has promising prospects and a high ability to remove pollution from aqueous solution. Furthermore, AC can be a realistic and affordable re-placement for pricey noble metals. Photocatalytic activities of the catalytic adsorbents are used as model pollutant (Riboflavin drug) under UV irradiation. ZnO/AC nanocomposites showed excellent photo-catalytic activity (~99% degradation of drug in 60 min) compared with that of bare ZnO NPs and AC. In addition, a recycle or reused experiment demonstrated the best stability of the nanocomposite; the ratio photo-degradation of ZnO/AC reached last more 70% after five cycle successive runs and possessed strong photo-catalytic ability. The improve photo-catalytic activities may be related to the effects of the relatively high surface area. The best data between the studied photo-catalysts appear the drug removal efficiency of ∼92% in 1 h under UV light irradiation.

Heterogeneous photocatalysts have been widely utilized for the degradation of pharmaceuticals in wastewater. Under UV light irradiation, photocatalysis of the Sulfadiazine Hydrochloride (SFD) drug in wastewater using Pd/ZnO nanocomposite was studied. The nanocomposite was prepared using a hydrothermal process. The incorporation of Pd nanoparticles into the ZnO nanostructure increased the porosity and surface area, as well as the number of functional and active sites of the nanocomposite, which can improve the photocatalytic process of drug removal. According to structural analyses using TEM and SEM, Pd/ZnO refers to a highly stable and architectural morphology. The photocatalytic degradation process revealed that after 60 min, it led to the removal of the SFD drug, and a degradation efficiency of up to 85.77% was obtained using ZnO NPs, while the complete Pd/ZnO nanocomposite photocatalytic process was obtained after 60 min, with a degradation efficiency of up to 92.25%. The high effectiveness of the prepared surface of the Pd/ZnO nanocomposite on the degradation of SFD drugs from aqueous solutions was confirmed, and the results showed the effective performance of the prepared photocatalyst in the removal of drugs. Likewise, reuse and regeneration have an important role to play in reducing the economic cost and secondary pollution, as the Pd/ZnO nanocomposite has a good ability to regenerate compared to zinc oxide, with a high percentage (92.25% to 82.87%) of four cycles.

Developing high-performance photocatalytic materials to remove contaminants from water sources is vital for health and environmental conservation. In this study, ZnO/Ni-doped Co3O4 heterojunction nanocomposites were successfully fabricated by sol-gel method and utilized as one of the most promising photocatalysts for the photocatalytic decolorization of reactive red 141 (RR141) dye. The concentration of Ni dopant was selected from 0 to 8 wt%. The prepared photocatalysts were characterized by X-ray diffraction (XRD) and field emission-scanning electron microscope (FE-SEM), energy dispersive X-ray spectra (EDS), and UV-visible diffuse reflectance spectra (UV-vis DRS) analysis. The optical band gap of ZnO nanoparticles, Co3O4 nanoparticles, ZnO/Co3O4, ZnO/2Ni-Co3O4, ZnO/5Ni-Co3O4, and ZnO/8Ni-Co3O4 nanocomposites was found to be 3.25, 2.54, 2.9, 3.78, 2.71, and 2.56 eV, respectively. The photocatalytic results demonstrated robust performance for ZnO/5Ni-Co3O4 nanocomposite in the decolorization of RR141 dye, achieving output as high as 97.4% under 100 min light irradiation. This enhanced photocatalytic efficiency can be attributed to the synergistic effects of Ni doping into Co3O4 lattice and its coupling with ZnO to form an n-p heterojunction ZnO/Ni-Co3O4 nanocomposite, which effectively improves light absorption and separates photogenerated charge carriers on the surface of the nanocomposite.

Porous CdS nanocrystalline thin film was synthesized via chemical bath deposition. The XRD (X-ray diffraction) pattern of the porous shows the cubic structure. FESEM (Field emission scanning electron microscopy) analysis shows that the surface of Cadmium sulfide (CdS) is a porous shape.  The EDX (energy dispersive X-ray spectroscopy) Technique assures the presence of Cd and S elements in the sample. To determine the band gap energy of porous CdS, UV-visible absorption spectra were analyzed, revealing an estimated value of approximately 2.39 eV. Subsequently, the photocatalytic degradation of methylene blue was using porous CdS as the catalyst. This degradation process took place under visible light irradiation from a 200-W xenon lamp. The utilization of porous CdS in this photocatalytic reaction demonstrates its potential as an effective catalyst for the degradation of methylene blue, a commonly used dye in various industries. To our knowledge, there is no previous study about porous CdS acting as catalysis to remove methylene blue dye. In seven hours, porous CdS removed 72% of methylene blue.

This study was conducted to evaluate the photocatalytic applications and the cytotoxicity effects of Ag-Se doped ZnO-Co3O4-NiO fivenary nanocomposite synthesized using polyanionic cellulose (PAC) polymer as a stabilizer agent. Several procedures such as XRD, FESEM, FTIR, EDX, PSA, and UV-Vis were applied to investigate synthesized nanocomposite. Consistent with the FTIR spectrum, chemical bonds were seen in the structure of the nanocomposite which approved the successful synthesis of them. The XRD pattern of the synthesized nanocomposite revealed sharp diffraction peaks with high crystallinity, and pure phases of Se, Ag, ZnO, NiO, and Co3O4 were approved with XRD analysis. FESEM/PSA images indicate that nanocomposite was synthesized with an average size of 23-49 nm and relatively uniformly distributed, in addition, it has a spherical morphology. The synthesized nanocomposite exhibited excellent photocatalytic activity to methyl orange (MO) dye degradation under a UVA light source. The degradation rate of nanocomposite reached 99% within 80 min. The kinetic studies indicate that the degradation of MO dye follows a first-order kinetic model. The cytotoxicity of the nanomaterial was assessed on normal mouse fibroblast NIH3T3 and cancer mouse melanoma B16F0 cell lines with the MTT assay. The results of the MTT test revealed significant cytotoxic influences on cancer B16F0 cells (IC50 value = 258.5 µg/mL) in comparison to normal cells.

In this paper, CoMoO4 Porous NanoSheets (PNSs) were successfully fabricated on a carbon cloth substrate by a low-temperature water bath method. Through morphological characterization and phase analysis, the synthesized product is CoMoO4 nanosheet, which has a porous structure with a diameter of about 400 nm and a thickness of about 100 nm. Through the electrochemical performance test, the synthesized product has good electrochemical performance. Under the condition of 1 A/g, the specific capacitance of CoMoO4 PNSs is 1800 F/g, and after 10000 cycles of charging and discharging, the capacity maintenance rate is 99.6%. CoMoO4 PNSs is a positive electrode, and activated carbon (AC) is a negative electrode. The device is assembled, and its theoretical voltage window reaches 1.6 V. After 8000 cycles of charging and discharging, the specific capacitance decreased from 121 F/g to 113 F/g, retaining 93.38% capacitance. In addition, we further studied the photocatalytic degradation of dyes on the synthetic materials. The degradation rates of Methyl orange (MO), Rhodamine B (RhB), and Congo Red (CR) dyes were 94.2%, 98.1%, and 96.4%, respectively. We further explored the cyclic stability of the material for RhB dye degradation. After 5 cycles of testing, it was found that the stability is very good, and can maintain 98.6%. The excellent electrochemical and photocatalytic properties of CoMoO4 PNSs are mainly attributed to the special porous sheet structure and CoMoO4 material. This work provides a new strategy and method for preparing excellent electrode materials and photocatalyst materials.

In this research, TiO2 nanoparticles were synthesized by sol-gel method and coated on the tile by using the Doctor Blade method. The TiO2 hydrophobic coatings were prepared by applying oleic acid and an organic binder on the tile substrate. The XRD, FESEM, Contact Angle, and FT-IR analyses characterized the manufactured coatings. According to the XRD pattern, the synthesized nanoparticles have good crystallinity, and two anatase and rutile phases have formed. The contact angle analysis showed that the contact angle increased by surface modification by using oleic acid. The antibacterial and photocatalytic activity of the coatings were evaluated in the decomposition of Escherichia Coli in various concentrations of bacteria and various dyes. The results confirmed the good antibacterial and photocatalytic activity of TiO2 coatings. The stability and durability of the coatings were examined by applying the salt spray test, Shore D test, and ultrasonic bath. The coatings revealed good anti-corrosion properties, and the hydrophobicity of the coatings was preserved after the salt spray test.

this project, keggin-type polyoxometalate, cationic exchange Q5PMoV2O40 (denoted as TBA-PMoV) was synthesized to produce a recoverable catalyst. This catalyst was characterized using X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), Field Emission scanning electron microscopy (FESEM) and UV-vis diffuse reflectance spectroscopy (UV-DRS). The synthesized catalyst showed high photocatalytic activity in the degradation of methylene blue as a pollutant under UV light irradiation. The effect of various factors such as catalyst amount, contact time and pH on degradation of methylene blue (denoted as MB) were investigated. Formal batch adsorption studies was applied for investigation of effects of various parameters, such as initial solution pH, initial dye concentration, catalyst amount, temperature, etc. Optimization results for 20 mg/L methylene blue showed that maximum degradation efficiency 96.8 % at the optimum conditions was found to be: catalyst amount 25 mg, pH= 7.6 and time 60 min at ambient pressure and temperature.

In this work, spherical α-Fe2O3 were synthesized using the facile co-precipitation followed by calcination at 500°C (Fe-1) and 700°C (Fe-2) for 3 h. The as-synthesized Fe-1 and Fe-2 samples were characterized by Fourier-transform Infrared (FT-IR) spectroscopy, X-ray powder diffraction (XRD), vibrating sample magnetometer (VSM) and transmission electron microscope (TEM). All results predict the successful preparation of Fe-1 and Fe-2 as soft magnetic materials. In addition, the photocatalytic activity of as-synthesized Fe-1 and Fe-2 were evaluated by degrading methylene blue (MB) dye is aqueous solution under simulated sunlight irradiation at low alkaline pH in the presence of a small amount of H2O2 as an oxidant. The effects of the initial pH of the solution and irradiation time on the photocatalytic properties were investigated. Under the best optimized conditions, Fe-1 exhibited better MB degradation with 94% efficiency than Fe-2 (78%). The kinetic study showed that the photocatalytic degradation of MB was followed by a pseudo first-order (PFO) model. The reusability studies of the samples predicted good stability and efficiency after 6 cycles.

There is a growing demand for use of alternative clean energy as against fossil fuel. In trying to meet these demands, researchers are investigating various approaches towards delivering affordable clean energy from the abundant biomass in our environment, including biodiesel. Esterification of oils is one of the advanced methods of oil technology, which changes the main structure of glycerides without causing chemical changes in the fatty acid that forms the structure of triglycerides. Biodiesel is an alternative fuel that is renewable and produces less harmful gases than fossil fuels. Among the sources of biodiesel are vegetable oils and animal fat. The use of free solar light sources is significant for producing clean energy and reducing the economic costs of photocatalysts. In the present work, these issues have been addressed and the work done has been reviewed. The focus of this research is to examine the studies conducted to investigate the efficiency of biofuel production from edible and non-edible oils using photocatalysts. Studies have shown the production of biodiesel with high efficiency. High efficiency for biodiesel production from this method shows the future use of this fuel.

In this study, zinc acetate (as a precursor) and activated carbon carboxylic acid derivative were used to create the nanostructure of zinc oxide (ZnO) as a matrix. The carboxylic acid derivative was produced by modifying the oxidized activated carbon with nitric acid (AC-COOH). The modified activated carbon's surface was then impregnated with zinc to load it. By using BET, XRD, and SEM to characterize the ZnO nanostructure, it was discovered that it was composed of nanoparticles with a surface area capacity of 17.78 m2 g-1 and a size range of 21–31 nm. The photocatalytic hydrolysis of the dye methyl orange in an aqueous medium served as a test case for the catalyst's performance. The primary variables were considered, including pH, catalyst dose, stirring effect, and starting dye concentration. Measurements of activity below UV light revealed satisfactory outcomes for photocatalytic hydrolysis of the methyl orange (MO). In addition, the efficiency of the methyl orange (MO) photolysis catalyst prepared with unmodified activated carbon was also evaluated. The outcomes proved that zinc oxide (ZnO), made using a derivative carboxylic acid of activated carbon molecules by a matrix, had more good photocatalytic action than zinc oxide (ZnO) made by the real activated carbon matrix.

In this work, carbon quantum dots (CQDs) were synthesized through a simple and efficient hydrothermal method with the usage of Trigonella foenum-graecum L. seeds as a raw material. The synthesis of CQDs was confirmed by the usage of FTIR, FESEM, EDX, TEM, UV-Vis, and PL analyses. The photocatalytic activity of CQDs was investigated for the degradation of Rhodamine B (RhB) dye as a target pollutant, resulting in the photodegradation percentage of 92% during 80 min, which indicates the effective role of CQDs in RhB decolorization under UVA-light irradiation. Also, the biocompatibility of CQDs was evaluated on normal (rat fibroblast) cell and cancer CT26 cell lines through the MTT assay, and the concentration-dependent cytotoxicity of CQDs was confirmed along with the IC50 value equal to 876 ppm against cancer CT26 cell lines.

Mesoporous silica nanoparticles (MSNs) were synthesized hydrothermally and modified with Co2+ and Zn2+. The as-prepared samples were denoted as MSN, Co-MSN(X), and Zn-MSN(X), where X is the Si/M molar ratio. In addition, co-modified MSN samples with both cations were also prepared and denoted as Co-Zn(Y)-MSN(X), where Y indicates the Zn2+ content in the range of 1-7 wt.% relative to Co2+. Correctness of the anticipated structures was approved by FTIR, XRD, SEM, EDX, BET, and XRF analyses. It was found that Co-Zn(7)-MSN(75) can be used as an efficient photocatalyst for discoloration of basic red 5 under very mild conditions. Up to 86% of basic red 5 was discolored after 3.75 h under the optimized conditions including catalyst dosage of 0.025 mg mL-1, pH=7, and irradiation of 4×8 W UV (254 nm) lamps. By using the Langmuir–Hinshelwood kinetics model, it was found that the reaction followed a pseudo-first-order kinetic.

In this paper, we examined the morphology, shape and magnetic and electronic properties of Selenium-doped nickel oxide nanoparticles (Se-doped NiO-NPs), which were achieved through a sol-gel technique that involved the usage of Cydonia oblonga plant extract. The structural and magnetic properties of Se-doped NiO-NPs were evaluated by the employment of XRD, FESEM / EDAX, FT-IR, UV-Vis, and VSM procedures. According to XRD studies, the nanoparticles accommodated a face-centered cubic (fcc) crystalline structure and a space group of (Fm3m). In addition, the size of nanoparticles in optimal conditions (the optimum temperature of 400 °C and 3% Se-doped) were reported to be 7.7 nm while a direct relationship was also observed with increasing the concentration of selenium. The FESEM images confirmed the spherical morphology of Se-doped NiO-NPs. Also, the photocatalytic properties of Se-doped NiO-NPs were evaluated through the usage of methylene blue (MB) pigment degradation under UV light. The outcomes of this evaluation exhibited more than 76 % of degrading within 200 min. To complete the project, the cytotoxicity aspect was also investigated on L929 cell lines, requiring the application of MTT assay, while the results were indicative of toxicity effects that can be used for inhibiting cancer cells.

Here, we report the production of hierarchical flower-like AgBiS2 nanostructuresby an amino acid-modified polyol route. This work indicates that by changing thepolyol process conditions including kind of capping agent, reaction time and refluxtemperature, the sheet-like, cone-like, sphere-like and flower-like morphologies ofAgBiS2 micro/nanostructures can be prepared. The phase, elemental composition,morphology and optical characteristics of as-prepared AgBiS2 nanostructures wereanalyzed by UV–Vis, FESEM, XRD, and EDS techniques. After characterization ofthe products, the AgBiS2 nanostructures were employed as novel photocatalystsfor oxidative desulfurization of thiophene/n-octane solution as model fuel undervisible light illumination. Results demonstrate that hierarchical flower-like AgBiS2photocatalyst with desirable band gap energy (2.44 eV) has high photocatalyticdesulfurization performance of about 89% after 2 h of visible light irradiation.As well as, the effects of morphology, photocatalyst dosage and reusability ofthe AgBiS2 nanostructures on the photocatalytic performance were evaluated.The excellent photocatalytic activity of AgBiS2 photocatalyst can be attributedto the strong visible light absorption, high separation rate of electron–hole pairs,special hierarchical structures and suitable band gap energy. Moreover, a reliablephoto-oxidation desulfurization mechanism was discussed according to theactive species trapping experiments, which revealed the photo-generated h+ and•O2 − radicals were the main active species in the photocatalytic desulfurizationprocess.