Showing 40 results for Hot
A. Jalaukan, S. Aldin M. Aldowaib, A. Salah Hammed, B. Ghanbari Shohany, R. Etefagh, A. Khorsand Zak,
Volume 16, Issue 4 (12-2019)
Abstract
In the research, Titanium dioxide/Graphene Oxide thin films at different concentration of graphene oxide (0.0, 0.015, 0.030, 0.045 and 4.5 g/ml) were prepared by spin coating method. Characterization of the samples was performed using X-ray diffraction and Field Emission Scannig Eelectron Microscope and Atomic Force Microscope. X-ray diffraction results show that by adding the graphene oxide, the peak associated with (001) reflection is observed at the angle of 10.5°. The analysis of Eenergy Dispersive X-ray also confirms the formation of graphene oxide sheets. Considering the excellent photo catalytic and antibacterial properties of titanium dioxide, the effect of adding the different concentration of graphene oxide on these properties has been investigated. The results show that the presence of graphene oxide increases the inhibition of Escherichia coli bacterial growth.
V. Tajer Kajinebaf, M. Zarrin Khame-Forosh, H. Sarpoolaky,
Volume 17, Issue 1 (3-2020)
Abstract
In this research, the nanostructured titania-coated silica microsphere (NTCSM) membrane consisting of titania-silica core-shell particles on α–alumina substrate was prepared by dip-coating method. The silica microspheres were synthesized by the Stöber method, and the nanostructured titania shell was obtained from a polymeric sol. Then, the prepared core-shell particles were deposited on alumina substrates. The samples were characterized by DLS, TG-DTA, XRD, FTIR and SEM. The photo-catalytic activity of the NTCSM membranes was evaluated using photo-degradation of methyl orange solution by UV–visible spectrophotometer. Also, physical separation capability was investigated by filtration experiment based on methyl orange removal from aqueous solution using a membrane setup. The mean particle size distribution of silica microspheres was determined to be about 650 nm that by deposition of titania nano-particles increased up to about 800 nm. After 60 min UV-irradiation, the dye removal efficiency was determined to be 80% by the membrane. By coupling separation process with photo-catalytic technique, the removal efficiency was improved up to 97%. Thus, the NTCSM membranes showed simultaneous photo-degradation and separation capabilities for dye removal from water.
M. Sadeghi, M. Hadi, O. Bayat, H. Karimi,
Volume 17, Issue 1 (3-2020)
Abstract
In this paper a constitutive equation was considered for the isothermal hot compression test of the Mn-Ni-Cr alloy. The hot compression test was performed in the strain rate range of 0.001-0.1 s-1 and deformation temperature was varied from 700 to 900 °C. A considerable reduction in flow stress was observed regardless of the strain rate when temperature was increased from 700 to 750 °C. DTA and XRD evaluation revealed that the removal of Mn3Cr phase and formation of the single solid solution phase were the reason for the flow stress reduction. At the low deformation temperature (700°C) and the high strain rate (0.1 s-1), a partially recrystallized microstructure was observed; this was such that with increasing the temperature and decreasing the strain rate, a recrystallized microstructure was completed. Also, the relationships between flow stress, strain rate and deformation temperature were addressed by the Zener-Holloman parameter in the exponent type with the hot deformation activation energy of 301.07 KJ/mol. Finally, the constitutive equation was proposed for predicting the flow stress at various strain rates and temperatures.
M. Mahdi, A. Abdul-Hameed, B. Ali, H.f Al-Taay,
Volume 17, Issue 1 (3-2020)
Abstract
Silicon nanowires (SiNWs) are synthesized through a metal-assisted chemical etching (MACE) method using Si(100) substrates and silver (Ag) as a catalyst. Scanning electron microscope (SEM) images confirmed that length of prepared SiNWs was increased when etching time increased. The prepared SiNWs demonstrated considerably low light reflectance at a wavelength range of 200–1100 nm. The photoluminescence (PL) spectra of the grown SiNWs showed a broad emission band peaked at a wavelength of about 750 nm. A solar cell and photodetector based on heterojunction SiNWs/PEDOT:PSS were fabricated using SiNWs that prepared with different etching time and its J–V, sensitivity, and time response were investigated. The conversion efficiency of fabricated solar cell was increased from 0.39% to 0.68% when wire length decreased from 24 µm to 21 µm, respectively. However, the sensitivity of the heterojunction SiNWs/PEDOT:PSS photodetector was decreased from 53774% to 36826% when wire length decreased from 24 µm to 21 µm, respectively.
A. Thakur, G. Reddy,
Volume 17, Issue 3 (9-2020)
Abstract
Mercury, one of the common pollutants in water, is known to affect human health adversely upon exposure. It is released in water not only by various natural processes but also by human activities. Methods developed so far for the detection of mercuric ions in water have limitations like sensitivity range, complex setup, skillful operation etc. Silver nanoparticles, due to unique properties, have been explored by researchers to develop better detection systems. Stable silver nanoparticles can be easily synthesized by methods of green chemistry, its reaction with mercuric ion can be easily observed by changes in color and UV-Vis spectra. The absorbance data from UV-Vis spectra can also be used in quantifying mercury concentration. In this paper, stable silver nanoparticles synthesized using silver nitrate as precursor, sodium lignosulphonate (LS) as reducing and stabilizing agent under microwave radiation are explored for detection of mercuric ions in water. Formation of AgNP was confirmed by UV-Vis band at 403.5nm. The intensity of this band showed a proportional decrease with increasing Hg+2 concentration. Hg+2 ions were detected by a distinct color change at higher concentration of Hg+2 also. The limit of detection (LOD) calculated from the observed absorbance data to be 0.7 ppm.
Reza Soleimani Gilakjani, Seyed Hossein Razavi, Masoumeh Seifollahi,
Volume 18, Issue 1 (3-2021)
Abstract
Niobium addition is an appropriate approach for improvement of superalloy’s operation. The purpose of this study is twofold: (1) to investigate on the η and γ/ phase precipitations along with (2) to identify the high-temperature tensile properties in A286 and Nb-A286, as a modified type. The heat treatment of both alloys was carried out in a two-stage aging procedure at 760°C for 16 h and 820°C for 2 to 30 hours, following characterized by optical and Scanning electron (SEM-EDS) microscopies, differential thermal analysis (DTA) and high temperature tensile tests. The results showed that niobium addition was increased the volume fraction of γ/ phase, from 10.7% to 12%, decreased its size, from 94 to 71 nm, and rising the γ/-dissolution temperature from 987°C to 1007°C. Moreover, the γ/ to η phase transformation was sluggishly occurred in Nb-A286 due to more stable of γ/ precipitations. Furthermore, the Nb-A286 alloy demonstrates higher mechanical properties than A286 one, approximately 100MPa improvement, which it was contributed to the much large volume fraction and finer size of more stabilized γ/ phase.
Masumeh Mohammadi, Hamidreza Rezaei Ashtiani,
Volume 18, Issue 2 (6-2021)
Abstract
The hot deformation behavior of the heat-treated AA6061 and AA 6063 aluminum alloys by T6-1, T6-2 artificial aging treatment, and O annealing treatment were studied by compression testing over a temperature range of 350–550
and strain rates of 0.005-0.1 s
-1. It was observed that the flow stresses of the studied aluminum alloys treated by the T6-1 and T6-2 heat treatments were significantly higher than those of the O annealing treatment. Moreover, the stress-strain curves of the heat-treated alloys by the T6-1, T6-2, and O heat treatments demonstrated significant softening during deformation at the lowest strain rate under any of the deformation conditions. For several strains, the activation energy of hot deformation was specified and obtained to vary significantly with strain for the heat-treated alloys by the T6-1 and T6-2 treatments. The stress-strain data calculated from a linear equation, with strain-dependent parameters, shows a great fit with the experimental data for the heat-treated aluminum alloys.
Prabhakar Kuppahalli, Ramaiah Keshavamurthy, Padmanathan Sriram, Ahobal Narayana,
Volume 18, Issue 2 (6-2021)
Abstract
The present investigation aims to synthesize RB031, RB032 manganese bronze alloys equivalent to HTB1 and HTB2 alloys with additions of silicon and to characterize them with the help of Microstructure and Mechanical properties. The methodology involves melting of alloy’s in a 300kg Coreless medium frequency induction furnace, casting them in Permanent and Shell moulds with optimum values of Zinc equivalent and retaining their high mechanical properties. The study includes the development and mechanical property measurements of the alloys synthesized. Characterization has been carried out using Optical Microscopy and Scanning Electron Microscopy with EDAX analysis for investiagtion of compositional variations and inquisition of hardness measurement & tensile properties. It is concluded from this work that RB032 alloy cast in Permanent moulds has superior hardness and tensile properties compared to Shell moulds and far exceeds that of NAB (AB2) alloys processed under similar conditions. Further, this investigation includes grain refinement by suitable Heat treatment studies to combat Hot Tearing since the strength is adequate enough with RB032 exhibiting higher hardness than other two alloys.
Usha Vengatakrishnan, Kalyanaraman Subramanian, Vettumperumal Rajapand, Dhineshbabu Nattanmai Raman,
Volume 18, Issue 3 (9-2021)
Abstract
Copper oxide (CuO) nanostructure particles were prepared using KOH/NaOH catalyst by low cost precipitation method and characterized by powder X-ray diffraction (PXRD), scanning electron microscope (SEM) and energy dispersive X-ray spectra (EDX) analysis. The photocatalytic dye degradation study of pure CuO nanostructure particles are analysed against two azo dyes (Direct black 38 (Black-E) and Congo red) under ultraviolet (UV) and solar irradiation. The release of major active species (*OH) in the photocatalytic degradation by as prepared CuO nanostructure particles were investigated by photoluminescence (PL) spectra with two different excitation wavelength (325and 355nm). The band gap of CuO nanostructure particles was calculated from diffuse reflectance spectra. The photocatalytic effect of CuO nanostructure particles is confirmed from the UV – Vis and photoluminescence spectra and also, further confirmed from the kinetic studies under UV and solar radiations. The photocatalytic degradation results revealed that 16.35% and 7.5% of black E and Congo red dye was degraded under UV, while it was 47.2% and 17.6% under solar light. The influence of pH on the photodegradation and change in the reaction temperature under solar irradiation were also analysed
Arian Heidar Alaghband, Azam Moosavi, Saeid Baghshahi, Ali Khorsandzak,
Volume 18, Issue 3 (9-2021)
Abstract
Porous nanostructured SnO2 with a sheet-like morphology was synthesized through a simple green substrate-free gelatin-assisted calcination process using Tin tetracholoride pentahydrate as the SnO2 precursor and porcine gelatin as the template. Crystalline phase, morphology, microstructure, and optical characteristics of the as-prepared material were also investigated at different calcination temperatures using X-ray diffraction (XRD), Field emission scanning electron microscopy (FESEM), UV-visible absorption, and Photoluminescence spectroscopy (PL), respectively. XRD patterns of all the samples revealed the presence of a tetragonal crystalline structure with no other crystalline phases. Moreover, the synthesized hierarchical sheets assembled with nanoparticles displayed a large surface area and porous nanostructure. The calculated optical band gap energy varied from 2.62 to 2.87 eV depending on the calcination temperature. Finally, photoluminescence spectra indicated that the nanostructured SnO2 could exhibit an intensive UV-violet luminescence emission at 396 nm, with shoulders at 374, violet emission peaks at 405 and 414 nm, blue-green emission peak at 486 nm, green emission peak at 534 nm and orange emission peak at 628 nm.
Ata Abdi, Mehrdad Aghaie-Khafri,
Volume 19, Issue 1 (3-2022)
Abstract
Hot Workability and Processing Map of High Gd Content Mg-Gd-Zn-Zr-Nd Alloy Hot deformation behavior of homogenized Mg-4Sn binary alloy was studied using compression tests at the temperature range of 300-500
and strain rates of 0.001-1s
-1. The material showed typical single peak flow behavior followed by a steady state flow as a plateau, which is more evident at the high value of Zener-Hollomon parameter. Constitutive analysis showed that in spite of the original Johnson-Cook (J-C), conventional strain compensated Arrhenius model based on Sellars-McTegart model has a reasonable agreement with the experimental data. Moreover, the well-known hyperbolic sine function fits the experimental data for predicting of the peak stress with a fair degree of accuracy.
M.j Kadhim, Fatima Allawi, M. A. Mahdi, Sami Najah Abaas,
Volume 19, Issue 3 (9-2022)
Abstract
Zinc Oxide (ZnO) nanorods and titanium dioxide (TiO2) nanostructures thin films were prepared onto glass substrates by the chemical bath deposition (CBD) method. The ZnO was structured as nanorods (NRs) while TiO2 was formed as nanoflowers plate as confirmed by Field-Emission Scanning Electron Microscope (FESEM) images. The ZnO/Fe3O4 and TiO2/Fe3O4 nanostructures thin films were prepared via drop-casting Fe3O4 NPs onto the grown ZnO and TiO2 nanostructures thin films. The diameter of Fe3O4 NPs was deposited onto ZnO NRs thin films and TiO2 nanostructures thin films was ranged from 8nm to 59nm with dominated range between 10nm to 30 nm. The crystalline structure of prepared samples was investigated through X-ray diffraction (XRD) method. However, the particles size of Fe3O4 was estimated by XRD as well as FESEM images was around 22 nm. The photocatalytic activity of the as-prepared ZnO/Fe3O4 and TiO2/Fe3O4 nanostructures thin films was investigated against methylene blue (MB) dye at room temperature with a pH value of 10 under different exposure time by visible light. The photodegradation rate of MB dye by ZnO/Fe3O4 and TiO2/Fe3O4 nanostructures thin films was higher than that obtained by ZnO and TiO2 nanostructures thin films. The best photodegradation rate of MB dye was 100% after exposure time of 180 min was obtained by ZnO/Fe3O4 nanostructures thin film whereas it was 82% for TiO2/Fe3O4 nanostructures thin films after exposure time of 240 min.
Saba Payrazm, Saeid Baghshahi, Zahra Sadeghian, Amirtaymour Aliabadizadeh,
Volume 19, Issue 3 (9-2022)
Abstract
In this research, zinc oxide quantum dots and graphene nanocomposites were synthesized via two different methods; In the first (direct) method, ZnO-graphene Nanocomposites were made mixing the synthesized zinc oxide and graphene. In the second (indirect) method, zinc nitrate, graphene, and sodium hydroxide were used to made ZnO-graphene Nanocomposites. XRD, FTIR and Raman spectroscopy analyses were used for phase and structural evaluations. The morphology of the nanocomposites w::as char::acterized by SEM. The specific surface area and porosity of the samples were characterized by BET analysis. The optical properties of the samples were investigated by photoluminescence and ultraviolet-visible spectroscopy analyses. Results showed that using graphene, increased the photoluminescence property and shifted the photoluminescence spectrum of the composites towards the visible light spectrum. The photoluminescence of the synthesized graphene-zinc oxide composite, in the visible light region, was closer to white light than that of pure zinc oxide. According to the results of BET test, the nanocomposite synthesized by direct method had a higher surface area (25.7 m2.g-1) and a higher porosity (0.32 cm3.g-1) than the nanocomposite synthesized by the indirect method with a specific surface area of (16.5 m2.g-1) and a porosity of 0.23 cm3.g-1).
Sreedevi Gogula, Sandhya Cole, Venkata Rao Kanakala, Gogula Jaya Ram Pavan Kumar, B Tirumala Rao,
Volume 19, Issue 4 (12-2022)
Abstract
The present study used a hydrothermal technique to synthesize undoped and Mn2+ doped CdS/Zn3(PO4)2 semiconducting nanocomposite materials. Powder X-ray diffraction, scanning electron microscopy, UV-Vis diffuse reflectance spectrometer, Fourier transform-Infrared Spectroscopy-FT-IR, and photoluminescence techniques were employed to study structural, optical, and luminescence properties of produced nanocomposites. The hexagonal structure of CdS and the monoclinic structure of Zn3(PO4)2 are both reflected in the powder X-ray diffraction spectra. When Mn2+ ions are present in the host lattice, a lattice distortion occurs, causing a phase change from the phase of γ-Zn3(PO4)2 to the β-phase of Zn3(PO4)2, without affecting the hexagonal phase of CdS. The average crystallite size of produced nanocomposites was 22-25 nm, and also calculated the lattice strain and dislocation density to better understand internal deformation of the samples. The FT-IR spectra were used to investigate the molecular vibrations and functional groups in the samples. The surface morphology of the nanocomposites is hexagonal spheres on rectangular shaped nano-flakes, and the interatomic distance between the hexagonal spheres is decreased as the doping concentration increases, forming a rod-like structure on the flakes. EDAX results confirm the presence of various relevant elements in the prepared samples. The quantum confinement of produced samples reduces as the Mn2+ doping concentration in the host lattice increases. The photoluminescence results demonstrate shallow trapped states due to the transition: d-d (4T1 → 6A1) of the tetrahedrally coordinated Mn2+ states and the impact of Mn2+ ions exhibiting several peaks in the UV-Visible region (365-634 nm) generating RGB (Red, Green, Blue) luminescence. Color coordinates and CCT values were calculated using the CIE diagram, and color correlated temperatures in the range of 2513–7307 K were discovered, which might be used in solid state lighting applications.
Hassan Tarikhum, Basil A Abdullah, Furqan Almyahi, Mazin Mahdi,
Volume 20, Issue 2 (6-2023)
Abstract
In this study, poly(3-hexylthiophene) (P3HT) and fullerene Indene-C60 multi-adducts (ICxA) were blended to create a formulation as a solution and thin films, which were prepared under ambient conditions. The optical properties of various compositional ratios were studied using UV-Visible absorbance and photoluminescence (Pl) measurements. The energy gaps of the prepared thin films and solutions were determined, and their values increased with increasing fullerene ratio because of the isolation of P3HT chains from their neighbors. Intensity ratio (IC=C/IC-C) with a small value in addition to a low value of full width at high maximum (FWHM) of Raman spectra are associated with increased conformation and high aggregation of composition. Furthermore, according to X-ray diffraction (XRD) results the 1:0.8 and 1:0.6 ratios have the largest crystallite sizes in comparison to the other ratios. The highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) levels for blends by electrochemical measurements were determined, which are sandwiched between those of the pure materials. In ambient conditions, binary organic photovoltaic cells (OPVs) at different ratios of the photoactive layer were evaluated. The device with a ratio of 1:0.6 had the best performance, with power conversion efficiency (PCE) of 1.21 %, open circuit voltage (VOC) of 0.53 V, short circuit current density (JSC) of 5.71 mA.cm-2, and fill factor (FF) of 39.5 % at a small Vloss of 1.39 V.
Amirreza Sazvar, Seyed Mohammad Saeed Alavi, Hossein Sarpoolaky,
Volume 20, Issue 2 (6-2023)
Abstract
We report a simple and practical approach for the easy production of superhydrophobic coatings based on TiO2-SiO2@PDMS. In this study, we used tetraethylorthosilicate (TEOS) and titanium tetraisopropoxide (TTIP) as a precursor for the sol-gel synthesis of SiO2 and TiO2, respectively. Afterward, the surface of nanoparticles was modified by 1,1,1,3,3,3-hexamethyldisilazane (HMDS) before being combined with polydimethylsiloxane (PDMS). The hydrophobic property of coatings was evaluated by static contact angle measurements. The phase composition and structural evolution of the coatings were examined by X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR) analysis. It was shown that changing the weight ratio of the solution composition of the coating can affect the hydrophobicity of the surface. The best sample has shown a superhydrophobic property with a 153˚ contact angle which contained (75%TiO2-25%SiO2) and PDMS at a weight ratio of 1:1. Moreover, the results showed that the superhydrophobic coating retains its hydrophobic properties up to a temperature of 450 ˚C, and at higher temperatures, it converts to a super hydrophilic with a water contact angle close to 0 ˚. The SiO2-TiO2@PDMS coating degrades methylene blue by about 55% and was shown to be capable of photocatalytically decomposing organic pollutants.
Maryam Salehi, Milad Dadashi, S. Parsa Kashani Sani,
Volume 20, Issue 2 (6-2023)
Abstract
In the present study, bulk refined-structured Al 5083 alloy with high mechanical properties was successfully fabricated by hot consolidation process of nanostructured melt- spun flakes. The influence of cooling rate and pressing conditions on the microstructure and mechanical properties of the alloy were investigated using X-ray diffractometer (XRD), optical microscopy (OM), field emission scanning electron microscopy (FE-SEM), microhardness, and compression tests. Rapid solidification combined with the hot consolidation at T=753 K (480 °C) and P= 800 MPa for 20 min produced a bulk sample with the desirable bonding, good microhardness (184.2±12.4 HV), and high strength (273±8 MPa) combined with 7 pct. fracture strain. These amounts are 78.6±5.1 HV, 148 ±9 MPa and about 5 pct. for the as-cast sample. Microstructural refinement during the controlled consolidation of nanostructure rapidly- solidified flakes contributes to such high mechanical properties of the bulk sample.
Salihah Alkhobrani, Hossein Bayahia, Fares T. Alshorifi,
Volume 20, Issue 3 (9-2023)
Abstract
In this study, CoFe2O4 (CoF) and ZnFe2O4 (ZnF) photocatalysts were successfully prepared by a facile and simple chemical precipitation method for degradation of methylene blue (MB) and methyl orange (MO) dyes under direct sunlight irradiation. The obtained ferrites were then characterized through XRD, TEM, EDS, UV-vis, and SEM. XRD and TEM results exhibited cubic nanostructures with sizes ranging from 9 to 16 nm and 11 to 18 nm for ZnF and CoF, respectively. SEM images showed homogenous, porous flat surfaces. EDS spectra confirmed the successful synthesis of ZnF and CoF nanostructures with high purity. UV-vis spectra results of MB and MO dyes showed maximum sunlight absorbance in the absence of ZnF and CoF, while a regular decrease in the sunlight absorbance was observed in the presence of ZnF and CoF within 15-60 min. The UV-vis results also showed that ZnF had higher photocatalytic activity than CoF. The experimental findings showed that the highest % degradation was 92.89% and 96.89% for MO and MB dyes, respectively, over ZnF compared to CoF photocatalyst (87.55% and 88.41% for MO and MB, respectively). These findings confirm that porous ZnF and CoF nanostructures are critical in promoting the degradation of dyes under sunlight instead of UV-vis light lamps that consume/require electrical energy.
Yugen Kulkarni, Niketa Pawar, Namrata Erandole, Muskan Mulani, Mujjamil Shikalgar, Swapnil Banne, Dipali Potdar, Ravindra Mane, Smita Mahajan, Prashant Chikode,
Volume 21, Issue 1 (3-2024)
Abstract
The paper investigates the solar photodegradation of Methylene Blue dye using copper oxide (CuO) thin films synthesized by the Successive Ionic Layer Adsorption and Reaction (SILAR) method. The structural, morphological, and optical characteristics of the CuO thin films have been investigated by employing a variety of methods, such as Fourier transform Infrared (FTIR) spectroscopy, UV-Vis spectroscopy, Scanning electron microscopy (SEM), and X-ray diffraction (XRD). The outcomes showed that CuO thin films with excellent surface shape and a highly crystalline nature had been successfully deposited. Methylene Blue was subjected to solar radiation during its photodegradation process, and the outcomes showed a significant decrease in the dye's concentration over time. To maximize the photo degradation process, the effects of other experimental factors were also assessed, such as the starting concentration of MB, the quantity of CuO thin film, number of SILAR cycles and the pH of the solution. Good photocatalytic activity is demonstrated by CuO thin films produced using the SILAR approach in the solar photodegradation of methylene blue. The development of affordable and ecologically friendly wastewater treatment technology that can use sun energy to break down persistent organic contaminants is affected by these findings.
Eswaran Kamaraj, Kavitha Balasubramani,
Volume 21, Issue 2 (6-2024)
Abstract
Heterostructure photocatalyst of CuWO4 modified SnO2 (CuWO4/SnO2) was fabricated by in simple wet-impregnation process and evaluated via degradation of rose Bengal (RB) under visible light irradiation. The samples had been completely characterized by Ultraviolet-visible diffuse reflectance spectroscopy (UV-vis-DRS), X-ray diffraction (XRD), Scanning electron microscopy (SEM) combined with energy-dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM), High-resolution TEM (HR-TEM), X-ray photoelectron spectroscopy (XPS) and Brunauer-Emmett and Teller surface analysis (BET). The result divulged that amongst the catalysts, CuWO4/SnO2 displayed higher photocatalytic activity than CuWO4 or SnO2. The enhanced photocatalytic efficiencies are attributed to the charge transfer from SnO2 to CuWO4 nanoparticles, which efficiently decrease electron-hole recombination energy level. The time required for maximum degradation of rosebengal (RB) under visible light over CuWO4/SnO2 was 180 min. The other parameters such as pH (pH=8), photocatalyst dosage (0.2 g/L) and dye concentration (20 µM) were optimized to achieve high degradation efficiency (98.5%). The excellent photocatalytic activity of CuWO4/SnO2 is due to efficient separation of photogenerated electron-hole pairs. The holes (h+) and superoxide radicals (O2•-) are the reactive species involved in photocatalytic mechanism for gdegradation of RB.
