Photocatalyst For Degradation Of Methyl Orange Research Articles

Optimization of Fe3O4@SiO2/Ag/AgCl/CdS nanocomposite via response surface methodology: an efficient visible-light photocatalyst for methyl orange degradation

Optimization of Fe3O4@SiO2/Ag/AgCl/CdS nanocomposite via response surface methodology: an efficient visible-light photocatalyst for methyl orange degradation

Synthesis of TiO2/Fe2O3 Nanocomposites as Photocatalyst for Methyl Orange Degradation

Fe2O3/TiO2 composites were successfully synthesized using the sol-gel method. The photocatalytic performance of prepared nanocomposites to degrade methyl orange under UV light irradiation was systematically investigated. The Fe2O3 added and calcination temperature were varied to study their effect on psychochemical properties. Further, to study the effect of psychochemical properties of the prepared nanocomposites on photocatalytic activity, X-ray diffraction (XRD), and scanning electron microscope Energy Dispersive X-ray spectroscopy (SEM-EDS) characterization were conducted. The visible light active Fe2O3 photocatalyst managed to decrease the bandgap energy of the prepared composites from 3.32 eV to 1.95 eV. This decrease in the band gap energy led to the composite being more active under visible light and less active under UV light irradiation. A composite with 6% Fe2O3 content exhibits the smallest degradation efficiency of 14% in 180 min, while the pure TiO2 nanoparticles are 94%. The results in this study provided important implications for further research on the preparation of composite TiO2 with Fe2O3 co-catalyst showing a promising route for improving the visible light activity of photocatalysts.

Core-shell Bi-containing spheres and TiO2 nanoparticles co-loaded on kaolinite as an efficient photocatalyst for methyl orange degradation

Improving the efficiency/cost ratio is the key to the practical application of photocatalysts. Using cheap minerals as carriers is an effective means to improve the efficiency/cost ratio of photocatalysts. Here, kaolinite was used to co-load TiO2 nanoparticles and Bi containing core-shell spheres forming the composites with excellent photocatalytic performance. The rate constant per unit mass of TiO2 in the optimal sample reached 18 times that of TiO2. Kaolinite plays important roles in promoting photocatalytic activity by improving the dispersion of TiO2 and the adsorption of O2 molecules and MO anions, besides the type-II energy band alignment of TiO2 and BixOy.

Synthesis of Ca-doped CeO2 Nanoparticles for the Enhanced Adsorption Activity of Chitosan and Other Applications

Calcium doped cerium oxide (CeO2) nanoparticles (NPs) were synthesized by co-precipitation method with ammonium ceric sulfate as the precursor and ethanol as solvent. They were characterized through X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy-dispersive X-ray (EDX) analyses. Pure CeO2 NPs have a crystallite size of 9 nm, while, calcium-doped ones have 2 nm and are having regular spherical shapes. Brunauer-Emmett-Teller (BET) surface analysis indicated that calcium-doped CeO2 NPs have larger specific surface area (59.806 m2/g) than pure CeO2 NPs (30-40 m2/g). As a result, chitosan incorporated with calcium doped CeO2 NPs showed better adsorption efficiencies (48-70%) than when incorporated with undoped CeO2 NPs (35-51%). Studies suggested that calcium doped CeO2 NPs are better potential photocatalyst for methyl orange degradation, with efficiencies between 25-68 % (in the time interval of 15-75 min) than their pure counterpart (2-15%).

Preparation and Electrochemical Study of Ag Nanoparticles Decorated on Gallium Arsenide as Photocatalyst for Methyl Orange Degradation Under Visible Light

Preparation and Electrochemical Study of Ag Nanoparticles Decorated on Gallium Arsenide as Photocatalyst for Methyl Orange Degradation Under Visible Light

Core-Shell Bi-Containing Spheres and Tio2 Nanoparticles Co-Supported on Kaolinite as an Efficient Photocatalyst for Methyl Orange Degradation

Core-Shell Bi-Containing Spheres and Tio2 Nanoparticles Co-Supported on Kaolinite as an Efficient Photocatalyst for Methyl Orange Degradation

Synthesis and characterisation of ammonia intercalated zinc hydroxide chloride hydrate: a potential photocatalyst for methyl orange degradation under sunlight

ABSTRACT In this work, ammonia intercalated zinc hydroxide chloride hydrate (ZHC-NH3), Zn5(OH)8Cl2.4[(H2O)x(NH3)1-x)] was synthesised using precursor, [ZnCl2.2{HONC(CH3)2}] by sol-gel method in presence of ammonia and characterised by FT-IR, SEM-EDX, and XRD analysis. On sintering at 500°C, ZHC-NH3 transformed to ZnO nanoparticles (ZnO NPs) as confirmed by the XRD patterns. ZHC-NH3 has nanoplates-like morphology with a positive surface charge (+28.8 mV) while synthesised ZnO nanoparticles (ZnO-NPs) have spherical morphologies with negative surface charge (−8.28 mV). Band gap of 2.7 eV was observed in ZHC-NH3 while in ZnO NPs it was obtained as 3.3 eV. A comparison has been done on the photocatalytic activities of ZHC-NH3 and ZnO NPs towards the degradation of methylene blue (cationic dye) and methyl orange (anionic dye) under sunlight and it was found that photo-degradation of anionic dye, methyl orange is superior (96.28%) in presence of ZHC-NH3 photocatalyst as compared to ZnO photocatalyst (55.42%). The adsorption capacities of ZHC-NH3 towards Pb2+, Cd2+, and Cr3+ heavy metal ions were found 47.00 mg. g−1, 20.40 mg. g−1, and 48.85 mg. g−1 whereas ZnO-NPs have adsorptions capacities of 46.97 mg. g−1, 43.07 mg. g−1, 29.21 mg. g−1, for Pb2+, Cd2+, and Cr3+ heavy metal ions, respectively.

Photocatalytic and Antibacterial Properties of a 3D Flower-Like TiO2 Nanostructure Photocatalyst.

Flower-like titanium dioxide (TiO2) nanostructures are successfully synthesized using a hybrid sol-gel and a simple hydrothermal method. The sample was characterized using various techniques to study their physicochemical properties and was tested as a photocatalyst for methyl orange degradation and as an antibacterial material. Raman spectrum and X-ray diffraction (XRD) pattern show that the phase structure of the synthesized TiO2 is anatase with 80-100 nm in diameter and 150–200 nm in length of flower-like nanostructures as proved by field emission scanning electron microscope (FESEM). The energy-dispersive X-ray spectroscopy (EDS) analysis of flower-like anatase TiO2 nanostructure found that only titanium and oxygen elements are present in the sample. The anatase phase was confirmed further by a high-resolution transmission electron microscope (HRTEM) and selected area electron diffraction (SAED) pattern analysis. The Brunauer-Emmett-Teller (BET) result shows that the sample had a large surface area (108.24 m2/g) and large band gap energy (3.26 eV) due to their nanosize. X-ray photoelectron spectroscopy (XPS) analysis revealed the formation of Ti4+ and Ti3+ species which could prevent the recombination of the photogenerated electron, thus increased the electron transportation and photocatalytic activity of flower-like anatase TiO2 nanostructure to degrade the methyl orange (83.03%) in a short time (60 minutes). These properties also support the good performance of flower-like titanium dioxide (TiO2) nanostructure as an antibacterial material which is comparable with penicillin which is 13.00 ± 0.02 mm inhibition zone against Staphylococcus aureus.

Green synthesis of bio-based Au@g-C3N4 nanocomposite for photocatalytic degradation of methyl orange

We report a unique, efficient and facile green synthesis of Au@g-C3N4 by using Averrhoa carambola leaf extract as a reducing agent. The composites are characterized by using different characterization techniques like XRD, DRS UV–vis, FT-IR, and TEM analysis to study the structural and optical properties. Further, photocatalyitic activity of the as synthesized nanocomposite is evaluated for the photocatalytic degradation of methyl orange. The as prepared 1 wt% Au@g-C3N4 with fresh leaf extract showed remarkable performance for methyl orange degradation under light illumination. The green synthesized Au@g-C3N4 could be used as an efficient photocatalyst for methyl orange degradation.

ZnO decorated on low carbonate NiAl-layered double hydroxide as efficient photocatalyst for methyl orange degradation

The decoration of zinc oxide (ZnO) nanorods on layered structure of low carbonate NiAl-layered double hydroxide (NiAl-LDH) was conducted by a combination of an aqueous solution of zinc chloride and an aqueous suspension of NiAl-LDH under hydrothermal method and subsequent calcination at 250 °C for 6 h. A series of the products, ZnO/NiAl-LDH(x), where x was a Zn2+ content, were characterized by X-ray diffraction, transmission electron microscopy, surface analysis, as well as UV–visible and photoluminescence spectroscopies. The slight shift of the reflection at around 11° as well as the appearance of two peaks at around 23° and 47° in the X-ray diffraction patterns, and the decrease of the vibration mode of CO32‐− (at 1359 cm−1) in Fourier transform infrared spectra confirmed the deintercalation of CO32− on/in layered double hydroxide. The presence of the reflections due to zinc oxide at around 32°, 33° and 36° and transmission electron microscope images demonstrated the images of zinc oxide nanorods distributed on the external surface of the hexagonal plates of the layered double hydroxide, verified the formation of zinc oxide crystal in the products. The band gap energy value of the products was highly dependent on the amount of zinc oxide in the products that played an important role in the photodegradation enhancement of methyl orange in aqueous solution and the catalytic reusing performance.

Sn21Cl16(OH)14O6: a promising novel photocatalyst for methyl orange degradation

Sn21Cl16(OH)14O6 was prepared using SnCl2, NaOH, and surfactant powder through a simple solid-phase reaction. The effects of surfactant addition on the phase composition, morphology, and photocatalytic properties of the photocatalyst were investigated. Results showed that the as-synthesized nanostructured Sn21Cl16(OH)14O6 had an average particle size of approximately 50–200 nm and a band gap of 3.82 eV. The addition of surfactants promoted the decomposition of Sn21Cl16(OH)14O6 into SnO and Sn and improved the photocatalytic property of Sn21Cl16(OH)14O6. The cetyltrimethylammonium bromide-modified sample possessed excellent photocatalytic properties and degraded 98.9% of methyl orange within 60 min under visible-light irradiation.

Curcumin functionalized CuO/Ag nanocomposite: Efficient visible light Z-scheme photocatalyst for methyl orange degradation

An aqueous green synthesis protocol was used to prepare two different curcumin functionalized CuO/Ag photocatalysts. The procedure involved the precipitation of fine spherical nanostructures of Ag on ˜250 nm long (needle-shaped) CuO with curcumin as the reducing and functionalizing agent. Synthesized photocatalysts were characterized by XRD and TEM. In contrast to CuO nanocatalysts, these nanocomposites are efficient visible light photocatalysts for aerobic methyl orange (MO) degradation. There is almost five times increase in photocatalytic activity on the incorporation of a suitable amount of Ag in this nanocomposite. Moreover, these photocatalysts also demonstrate good recyclability for this reaction. Appropriate reactive species trapping experiments confirmed that superoxide radicals were the main active species responsible for the degradation reaction. On the other hand, the water oxidation transfers electrons to photo-generated valence band holes. The results suggest that the photocatalyst works by a Z-scheme charge transfer from the CuO to curcumin through the plasmonic Ag component.

Synthesis and Characterization of a ZnO/CuO/Ag Composite and its Application as a Photocatalyst for Methyl Orange Degradation

Synthesis and Characterization of a ZnO/CuO/Ag Composite and its Application as a Photocatalyst for Methyl Orange Degradation

Incorporation of ZnO-Al layered double oxide in AgMCM-41 nanocomposite for photodegradation of dye

Abstract In the present study, the synthesis of [ZnO-Al] LDO/AgMCM-41 nanocomposite was suggested. The new nanocomposite was prepared in three steps: (i) synthesis of AgMCM-41 by incorporation of silver nanoparticles (Ag NPs) in MCM-41 via heat treatment method, (ii) preparation of layered double hydroxides (LDH) containing Zn and Al in AgMCM-41 through the co-precipitation method (iii) preparation of ZnO-Al layered double oxide (LDO) in AgMCM-41 by calcination of [Zn-Al] LDH/AgMCM-41. The new nanocomposite was a visible-light-driven photocatalyst for degradation of methyl-orange (MO) dye. The nanocomposite was characterized by XRD, TEM, BET, and DRS methods. The results showed the presence of Ag and ZnO NPs in nanocomposte. The nanocomposite indicated a surface plasmon resonance (SPR) band in the visible region related to silver NPs. The formation of [ZnO nanorods-Al] LDO over AgMCM-41 was observed by TEM. The photocatalyst demonstrated 90% removal efficiency for MO dye under visible light after 60 min. Kinetic research showed that the reaction rate constants [ZnO-Al]LDO/AgMCM-41 and [Zn-Al] LDH/AgMCM-41 were approximately 1.8 and 1.6 times higher than the apparent reaction rate constant of [Zn-Al] LDH. The photocatalytic activity of LDO was enhanced in presence of AgMCM-41 due to reduction of recombination rate of the electro-hole in ZnO semiconductor.

Coherent Bi2O3-TiO2 hetero-junction material through oriented growth as an efficient photo-catalyst for methyl orange degradation

In this work, we report the synthesis of a Bi2O3-TiO2 hetero-junction (HJ) material through a facile colloidal method. The hetero-junction formation follows a growth with a 145°Bi2O3/TiO2 crystal angle, owing to the large lattice mismatch between Bi2O3 and TiO2 crystals. With the Bi2O3-TiO2 hetero-junction material as a photocatalyst, methyl orange is degraded completely within two hours under common UV-lamp irradiation. The photo-catalyst remains highly-active for complete photo-degradation of methyl orange even after multiple experiments. The remarkable photo-catalytic properties are attributed to the remarkable mono-dispersivity of the colloidal Bi2O3-TiO2 nano-structure as well as the refined band structure with a valence band of 0.85 eV below that of TiO2 crystal.

Insight into the enhanced photocatalytic performance of Ag3PO4 modified metastable hexagonal WO3

A metastable hexagonal WO3 (h-WO3) was prepared by a hydrothermal reduction method with glycerol and the Ag3PO4/h-WO3 composites were synthesized via a precipitation method. Several techniques were employed to characterize the Ag3PO4/h-WO3 composites. Compared to the Ag3PO4/WO3 photocatalysts, the Ag3PO4/h-WO3 photocatalysts exhibited an excellent visible light photocatalytic performance for efficient degradation of methyl orange (MO). The analysis results showed that the favorable photocatalytic performance of the Ag3PO4/h-WO3 composites were mainly attributed to the h+ and O2− generated during the recycles of W6+ and W5+. Furthermore, under the same conditions, the Ag3PO4/h-WO3 composites showed better stability than pure Ag3PO4 photocatalyst for degradation of MO, indicating that h-WO3 played an important role in the process of degradation. Based on the results of trapping experiments and XPS characterization analysis, the photocatalytic mechanism of the Ag3PO4/h-WO3 composites were proposed.

Preparation of renewable porous TiO2/PVA composite sphere as photocatalyst for methyl orange degradation

Firstly, preparation of porous polyvinyl alcohol (PVA) spheres were investigated in detail by phase inversion method using N,N-dimethylacetamide (DMAc) and polyvinylpyrrolidone (PVP) as pore-forming additives. The morphology and pore structure of PVA spheres were characterized by SEM and BET measurements. It was found that the addition of DMAc and PVP increased the pore volume and the surface pore size of PVA sphere respectively. The maximum surface area of the porous PVA sphere reached 220 m2/g. Secondly; the synthesis of photoactive TiO2 NPs (anatase type) at the low temperature was developed by controlling the aging process of the TiO2 precursors. The crystallinity and photoactivity of TiO2 NPs increased with the aging time. Finally, TiO2 NPs/PVA composite spheres were prepared by immersing PVA sphere into TiO2 precursor solution. Their structures were characterized by XRD pattern, TEM and TGA measurement. It was found that TiO2 NPs were successfully immobilized into PVA spheres. The photodegradation of methyl orange (MO) under UV light by TiO2/PVA spheres showed a good photocatalytic efficiency. Moreover, TiO2/PVA spheres can be easily regenerated by the repeated immersion process. Overall, the porous TiO2/PVA sphere displays a good photoactive property and an advantage of easier recovery, which facilitates its application in large-scale wastewater treatment.

Effect of Different Activated Carbon as Carrier on the Photocatalytic Activity of Ag-N-ZnO Photocatalyst for Methyl Orange Degradation under Visible Light Irradiation.

In order to enhance the photodegradation of methyl orange (MO) by ZnO under visible light irradiation, ZnO nanoparticles co-doped with Ag and N and supported on activated carbon (AC) with different properties were synthesized through the sol-gel method. The prepared photocatalysts were characterized in terms of the structure and properties through X-ray diffraction, N2 adsorption-desorption, ultraviolet-visible (UV-vis), diffuse reflectance spectroscopy, X-ray photoelectron spectroscopy, photoluminescence, and electron spin resonance. The photocatalytic activities of these photocatalysts followed the order: Ag-N-ZnO/ACs > Ag-N-ZnO > N, or Ag single-doped ZnO > commercial ZnO. This result was attributed to the small particle size, large surface area, narrow band gap, and high charge separation of Ag-N-ZnO/ACs. The Ag-N-ZnO/coconut husk activated carbon (Ag-N-ZnO/CHAC) exhibited the highest degradation efficiency of 98.82% for MO under visible light irradiation. This outcome was due to the abundant pore structure of Ag-N-ZnO/CHAC, resulting in stronger adsorption than that of other Ag-N-ZnO/ACs. Moreover, the degradation of MO on photocatalysis followed first order kinetics. The reactive species ·OH and ·O2− played more important roles in the photocatalytic degradation of MO over composite photocatalyst. Ag-N-ZnO/CHAC photocatalyst exhibited higher photocatalytic activity than unsupported Ag-N-ZnO after five recycling runs.

Formation of Cobalt Doped Zinc Oxide Photocatalyst for Methyl Orange Degradation

The formation of cobalt (Co) doped zinc oxide (ZnO) as photocatalyst for photodegradation of methyl orange dye was investigated. The ZnO photocatalyst was produced with different concentration of Co by using sol gel method. The hexagonal wurtzite and zincite structure were successfully formed through this method. The morphological observation of nanorod and nanodisk structure formed was done by Field Emission Scanning Electron Microscope (FESEM). While, the structural properties of Co doped ZnO were identified by X-ray Diffraction (XRD) and Raman spectroscopy. The degradation performance of methyl orange was assessed and performance of photocatalytic activity was correlated to the amount of dopant level and oxygen vacancy of photocatalyst. There is an optimum amount of Co that can be doped into ZnO nanostructure in order to provide better degradation of methyl orange.

Hydrothermal Synthesis and Characterization of Cu2+/F– Co-Doped Titanium Dioxide (TiO2) Nanotubes as Photocatalyst for Methyl Orange Degradation

Hydrothermal Synthesis and Characterization of Cu²⁺/F^– Co-Doped Titanium Dioxide (TiO₂) Nanotubes as Photocatalyst for Methyl Orange Degradation