Arezoo Ghadi; Sharieh Hosseini
Abstract
The aim of this research work is to investigate sorption characteristic of synthesized polypyrrole / polyaniline (PPy / PANI) nano fiber for Cu (II) removal from paper mill wastewater. The sorption is carried out by batch method. The structural characterization of this sorbent was performed by SEM and ...
Read More
The aim of this research work is to investigate sorption characteristic of synthesized polypyrrole / polyaniline (PPy / PANI) nano fiber for Cu (II) removal from paper mill wastewater. The sorption is carried out by batch method. The structural characterization of this sorbent was performed by SEM and FTIR analysis. The optimum conditions of copper sorption from paper mill wastewater onto PPy / PANI were found to be: pH=6, contact time 12 min and 0.4 g of sorbent in 100 ml in wastewater. The kinetic studies showed that the sorption process was well described by the pseudo second order kinetic model. Also, Langmuir isotherm provided the best fit to the equilibrium data. Also the effect of temperature on the process was found that the temperature has positive effect on the process. Thermodynamic parameters showed that the sorption of copper onto nano fiber were feasible, spontaneous and endothermic under studied conditions.
Sanjay Dhanaji Jadhav; R. S. Patil
Abstract
The photocatalytic degradation of methyl orange and Congo red dye was performed under the illumination of visible light (Philips 250Watt) as a source of photons. The complete distraction of the aromatic ring was ascertained by UV spectroscopic analysis. A decrease in dye concentration and an increase ...
Read More
The photocatalytic degradation of methyl orange and Congo red dye was performed under the illumination of visible light (Philips 250Watt) as a source of photons. The complete distraction of the aromatic ring was ascertained by UV spectroscopic analysis. A decrease in dye concentration and an increase in the concentration of CO2 indicate dye mineralization. The behavior of this reaction was pseudo-first-order and the maximum photodecolorization efficiency was ~85.16% for Methyl orange and ~ 95.40 for Congo red in 120-150 min. at 30oC.
Emelda Rayappan; Jayarajan Muthaian; Muthirulan Pandi3
Abstract
A simple chemical methodology has been adopted for the synthesis of zirconium (Zr) doped and un-doped cadmium selenide (CdSe) nanoparticles for the application towards photocatalytic degradation of indigo carmine (IC) dye under solar light irradiation. The as prepared Zr-CdSe (doped) and CdSe (un-doped) ...
Read More
A simple chemical methodology has been adopted for the synthesis of zirconium (Zr) doped and un-doped cadmium selenide (CdSe) nanoparticles for the application towards photocatalytic degradation of indigo carmine (IC) dye under solar light irradiation. The as prepared Zr-CdSe (doped) and CdSe (un-doped) nanoparticles were characterized by ultraviolet visible spectroscopy (UV-vis), X-ray diffraction (XRD), Scanning electron microscopy (SEM) coupled with energy dispersive X-ray analysis (EDAX) and Transmission electron microscopy (TEM) studies. The inclusion of Zr ion into the CdSe nanoparticles matrix was confirmed by SEM-EDAX and XRD studies. TEM studies confirm the zirconium ions are uniformly doped over the CdSe surface. The photocatalytic degradation performance of Zr doped and un-doped CdSe nanoparticles were examined for the degradation of IC dye under solar light irradiation. The experimental results showed that the Zr doped CdSe possessed greater photocatalytic activity in comparison to un-doped CdSe. Photodegradation process parameters such as the initial concentration of the dye, as well as the amount of catalyst and time were investigated. The photocatalytic degradation rate was favored by a high concentration of solution in respect to Langmuir–Hinshelwood model.
Elham Aseman-Bashiz; Hossein Sayyaf
Abstract
This study was conducted with the aim of introducing a new sono-Fenton system containing nano-pyrite catalyst and hydrogen peroxide (HP) for the effective removal of tetracycline (TC) from aqueous solutions. The synthesized nano-pyrite was characterized through XRD, FTIR, FE-SEM, and EDX analyses. The ...
Read More
This study was conducted with the aim of introducing a new sono-Fenton system containing nano-pyrite catalyst and hydrogen peroxide (HP) for the effective removal of tetracycline (TC) from aqueous solutions. The synthesized nano-pyrite was characterized through XRD, FTIR, FE-SEM, and EDX analyses. The best performance of the sono-Fenton nano-pyrite/HP system was observed under the condition of pH 3.0, TC 8.0 mg/L, HP 4.0 mM, ultrasound (US) 40 W, nano-pyrite 1.0 g/L, and 20 min with 93.1% removal efficiency. Comparison of the efficiency of the proposed system components confirmed the remarkable synergy between sono-catalysis and Fenton reactions due to the simultaneous application of nano-pyrite, HP, and US power. Meanwhile, US irradiation caused fluidization, turbulence, mass transfer, and nano-pyrite surface cleaning due to its cavitation and oscillation effects. According to the tracer test, the main agent of TC degradation in the sono-Fenton process was HO^•. The results showed that the TC removal efficiency from the first to the fourth run reached from 93.1% to 70.3%. This means that the recyclability of nano-pyrite has been very successful. Overall, the proposed sono-Fenton system was an efficient and sustainable process for the rapid and effective removal of pharmaceutical contaminants from water and wastewater.
Mohammad Reza Jalali Sarvestani; Zohreh Doroudi
Abstract
Reactive black 5 is a toxic dye that has adverse effects on the environmental ecosystems and the health of human beings. Therefore, its removal is very important. Among the reported methods adsorption gathered a huge attention in the recent years because of its simplicity and low-cost. In this review ...
Read More
Reactive black 5 is a toxic dye that has adverse effects on the environmental ecosystems and the health of human beings. Therefore, its removal is very important. Among the reported methods adsorption gathered a huge attention in the recent years because of its simplicity and low-cost. In this review paper, removal of reactive black 5 by adsorption method from waste waters was evaluated and all of the achievements from the past to the present were discussed in detail. The influence of important operational parameters on the adsorption efficiency of reactive black 5 such as pH, temperature, adsorbent dosage and initial dye concentration was investigated. In addition, the reported adsorbents for reactive black 5 were divided into different groups on the basis of their nature (like nanostructures, natural materials, by products and chitosan based adsorbents) and their important characteristics, including adsorption capacity, removal percentage, initial dye concentration, repeatability, the synthesis cost and optimized experimental parameters are compared with each other in detail. Moreover, important conclusions have been made from the surveyed literature and some suggestions are proposed for the future works.
D Kamarajan; Benny Anburaj; V Porkalai; A Muthuvel; G Nedunchezhian; N Mahendran
Abstract
The current study aimed to synthesize nanoparticles of Zinc oxide (ZnO) using the extract of Acalypha indica leaves and their photocatalyst degradation and antibacterial properties were also measured. The biosynthesized nanoparticles were analyzed using XRD, UV-visible, FT-IR, and SEM with EDAX, DLS, ...
Read More
The current study aimed to synthesize nanoparticles of Zinc oxide (ZnO) using the extract of Acalypha indica leaves and their photocatalyst degradation and antibacterial properties were also measured. The biosynthesized nanoparticles were analyzed using XRD, UV-visible, FT-IR, and SEM with EDAX, DLS, PL, and Zeta potential analysis. The synthesized nanoparticles had a mean size of 16 nm measured by XRD which was highly pure, and their spherical shape was confirmed by SEM. The UV-visible confirmed that ZnO nanoparticles have a direct band gap energy is 3.34 eV. The measured zeta size and potential of synthesized nanoparticles were 46 nm and -27 mV, respectively, determined by the DLS technique can be considered moderately stable colloidal solutions. The FT-IR analysis confirmed the presence of functional groups in the leaf extract and the ZnO nanoparticles. The biosynthesized ZnO nanoparticles have a homogeneous spherical morphology and the average particle is 35 nm. The PL analyses performed on synthesized nanoparticles showed a sharp blue band at 362 nm, which was attributed to the defects of structure in ZnO crystals. During natural sunlight illumination, ZnO nanoparticles demonstrated notable degradation of the dye methyl blue (MB). At 90 min of illumination, the degradation efficiency achieved was 96 %. Antibacterial properties were observed for synthesized nanoparticles against four bacterial strains, including Bacillus subtilis, Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli. The highest zone of inhibition was observed against Escherichia coli (25.2 mm). Overall, these studies indicate that Acalypha indica is a good sell for planting, and has the greatest chance of being used to develop nanoparticles for protection against environmental pollution and human health.
Amir Hossein Baghaie; Aminollah Aghilizefreei
Abstract
Decreasing the heavy metals availability has important key factors in environmental studies. This research was done to investigate the effect of nano-Fe oxide and nano-hydroxyapatite (NHAP) on Cd uptake by plant that cultivated in the sewage sludge amended soil. Treatments consisted of applying Cd (0, ...
Read More
Decreasing the heavy metals availability has important key factors in environmental studies. This research was done to investigate the effect of nano-Fe oxide and nano-hydroxyapatite (NHAP) on Cd uptake by plant that cultivated in the sewage sludge amended soil. Treatments consisted of applying Cd (0, 10 and 20 mg Cd/kg)-polluted sewage sludge at the rates of 0, 15 and 30 t/ha, nano-Fe oxide (0 and 0.5 ppm) and NHAP (0, 0.5 and 1 % (W/W)). The plant in this experiment was pinto bean (Cv. Khomein). After 90 days, the plants were harvested and the plant Zn, Cd and Fe concentration was measured using AAS. In addition, soil microbial respiration was calculated. Soil application of NHAP significantly increased the Zn and Fe concentration of the plants that cultivated in the soil which was amended with 15 t/ha sewage sludge by 12.8 and 14.5%, respectively. However, the Cd concentration was decreased by 17.2%. Using 15 and 30 t/ha sewage sludge significantly increased the plant Zn and Fe by 13.1 and 14.6%, respectively. Foliar application of nano-Fe oxide ate the rate of 1 ppm significantly decreased the plant Cd uptake by 18.3%. Using NHAP (0.5 % (W/W)) and sewage sludge (30 t/h) significantly increased the soil microbial respiration by 14.2 and 15.3%, respectively. The results of this study showed that using organic amendments such as NHAP and sewage sludge or foliar application of nano-Fe oxide can affect in decreasing the heavy metal uptake by plants that is a positive point in environmental studies.
Deepak Singhwal; Amita Khatri; Pawan Rana
Abstract
The present work reports the synthesis of Cetyl trimethylammonium Bromide (CTAB) assisted CdO nanoparticles with different concentration of CTAB (0.0M, 0.04M, 0.08M and 0.12M) by co-precipitation and their potential application in photocatalysis. X-Ray Diffraction (XRD) results indicate that crystallite ...
Read More
The present work reports the synthesis of Cetyl trimethylammonium Bromide (CTAB) assisted CdO nanoparticles with different concentration of CTAB (0.0M, 0.04M, 0.08M and 0.12M) by co-precipitation and their potential application in photocatalysis. X-Ray Diffraction (XRD) results indicate that crystallite size increases as concentration of CTAB is increased. Field Emission Scanning Electron Microscope (FESEM) exhibit that flat sheet-like morphology is changing into thin needle-like structure with concentration of surfactant. Elemental Dispersive X-ray Spectroscopy (EDS) confirmed existence of constituents and hence marks purity of prepared samples. Broad peak of Raman spectra is consisting of three bands from 200-500 cm-1 while Fourier Transform Infrared (FTIR) spectra certifies vibration of Cd and O bond are present at 530 cm-1. Optical Band gap is found to slightly decrease due to addition of CTAB. Dye degradation results showed that CdO nanoparticles can degrade Methylene Blue (MB) dye and Rose Bengal (RB) Dye degrades upto 83% and 85% respectively within 80 minutes of light irradiation.
Pijushkanti Purkait; Arijita Bhattacharyya; Sankhajit Roy; Saikat Maitra; Gopes Das; Mahua Ghosh Chaudhuri
Abstract
This article reports the green synthesis of titanium dioxide nanoparticles (TiO2 NPs) from aqueous leaf extract of Trema Orientalis (L) and its effectiveness in photodegradation process of zoxamide under UV irradiation(λ max ≥ 250 nm) . Titanium (IV) isopropoxide act as the precursor and leaf ...
Read More
This article reports the green synthesis of titanium dioxide nanoparticles (TiO2 NPs) from aqueous leaf extract of Trema Orientalis (L) and its effectiveness in photodegradation process of zoxamide under UV irradiation(λ max ≥ 250 nm) . Titanium (IV) isopropoxide act as the precursor and leaf extract act as the reducing agent. The synthesized TiO2 NPs are confirmed by the powder X-ray diffraction (XRD) analysis and the crystalline size was calculated by the Scherrer’s formula(52nm) and as well as Williaman-Hall(W-H) equation(59 nm). The Dynamic Light Scattering (DLS) analysis shows the stability and particle size approximately 88-94 nm of the synthesized TiO2 NPs. The Fourier Transform Infrared Spectroscopy (FTIR) analysis confirms the presence of various functional groups in the synthesized NPs. The UV absorption wavelength observed at the peak of 351 nm and the calculated energy band gap is found to be 3.27eV. The surface morphology of the synthesized TiO2 NPs is determined by using Scanning Electron Microscopy (SEM). The rate of photodegradation of zoxamide in acetonitrile/water solvent system followed pseudo first-order kinetics, and calculated half-lives were found to be in the range of 2.33 -10.46 h. From this study, one photoproduct was isolated and characterized on the basis of column chromatography, mass spectral data and X-ray crystallography. The isolated photoproduct was identified as 3,5-dichloro-4 methyl benzoic acid. The plausible mechanistic pathway of formation of the photoproduct is also depicted. Langmuir–Hinshelwood (L–H) kinetic model was proposed for the rate equation of the zoxamide photodegradation in presence of TiO2 NPs under UV irradiation.
Manmeet Kaur; Dixit Prasher; Ranjana Sharma
Abstract
The presence of various hazardous toxins such as Phenols, phthalates, pesticides, dyes, heavy metals, pharmaceutical waste, etc, is continuously increasing into the water bodies from different agricultural, industrial and domestic practices, which have brought the toxicity level to an alarming height. ...
Read More
The presence of various hazardous toxins such as Phenols, phthalates, pesticides, dyes, heavy metals, pharmaceutical waste, etc, is continuously increasing into the water bodies from different agricultural, industrial and domestic practices, which have brought the toxicity level to an alarming height. Often, these toxic compounds are quite stable in nature and the removal or degradation of these compounds is quite challenging, which further poses a significant threat to the environment. When it comes to enhance the efficiency of water purification and decontamination process, SnO2 nanoparticles offer great potential owing to their low concentration and large surface area. Over the past few years, SnO2 nanoparticles as a photocatalyst has garnered huge interest from the researcher community towards the photo-degradation of toxic pollutants present in the water bodies. Among various metal oxides, particularly SnO2 has been emerged as the most versatile material for doping of different transition metals due to its plethora of applications such as photocatalysis, energy harnessing, sensors, solar cells and optoelectronic devices. The pure and doped SnO2 has prominent significance due to its phenomenal catalytic and physicochemical properties such as chemically stable, inexpensive and non-toxic. This review explores and summarizes the progress of first and second transition metal series doping in SnO2 for its coherent application towards the degradation of water pollutants. We have emphasized the effect of different transition metal dopants used in the growth of SnO2 nanoparticles on the basis of their synthesis technique, source of irradiation used, nature of contaminations removed and obtained photodegradation efficiency.
PARMESHWAR LAL MEENA; Ajay Kumar Surela; Krishna Poswal
Abstract
Here in the present study, we report the synthesis of ZnO nanoparticles, ZnO/CuO(3%), ZnO/CuO(5%), and ZnO/CuO(10%), nanocomposites using simple precipitation method with variation of CuO content and the activities of prepared samples were investigated for degradation of Brilliant Cresyl Blue (BCB) dye ...
Read More
Here in the present study, we report the synthesis of ZnO nanoparticles, ZnO/CuO(3%), ZnO/CuO(5%), and ZnO/CuO(10%), nanocomposites using simple precipitation method with variation of CuO content and the activities of prepared samples were investigated for degradation of Brilliant Cresyl Blue (BCB) dye under visible light conditions in aqueous solutions. The structural, morphology, optical and compositional characteristics of fabricated samples were characterized by using Fourier Transform Infra-Red (FTIR) Spectroscopy, Field Emission Scanning Electron Microscopy combine electron dispersive spectroscopy (FESEM-EDS) and UV-vis spectroscopy. FESEM images show that ZnO nanoparticles are polygon like shape structure while ZnO/CuO have polygon and sheet shape structures. XRD patterns reflect the high crystalinity and purity of samples. The optical band gap values determined from optical absorption method indicate that band gap energy decreased with increase of CuO content in ZnO. The catalytic efficiency of the ZnO/CuO hybrid nanocomposite was observed to be higher than the ZnO nanoparticles under similar reaction conditions, 97.30% of Brilliant Cresyl Blue (BCB) dye was degraded after 100 min of irradiation of visible light radiation using the ZnO/CuO(5%) hybrid nanocomposite. The higher efficiency of ZnO/CuO compare to ZnO may be due to increased surface area and decreased band gap energy. The kinetic study of the photoctalytic degradation displayed that hybrid ZnO/CuO degrdaded dye with high rate constant k (34.88x10-3 min -1) compare to ZnO (k, 7.00x10-3 min-1). The optimization of reaction conditions of photodegradation process were attained by the variation in reaction factors such as pH, dye concentration, catalyst amount, and reaction time.
Devarapalli Venkata Padma; Susarla Venkata Ananta Rama Sastry
Abstract
The aim of this work is to exploit low cost and efficient sorbent for removal of heavy metals from the aqueous solution using Mallet Flower Leaf Powder (MFLP). MFLP is processed into a fine powder and used as a bio-adsorbent. Experiments are conducted to find out the feasibility of metal recovery process ...
Read More
The aim of this work is to exploit low cost and efficient sorbent for removal of heavy metals from the aqueous solution using Mallet Flower Leaf Powder (MFLP). MFLP is processed into a fine powder and used as a bio-adsorbent. Experiments are conducted to find out the feasibility of metal recovery process to reclaim the metals. The adsorption rates of both Chromium and Copper are lowered by 3.4% and 48.4% respectively in contrast to those obtained when only one metal is present in the solution. The presence of Copper along with Chromium has not much affected the adsorption rates of Chromium. There is higher adsorption rate for Chromium than for Copper at different temperatures. In the binary system, the copper adsorption rate is found to be suppressed by the presence of Cr(VI). The uptake of Cr(VI) is higher in the binary system than the single system, while the uptake of Cu(II) is lower in the binary system than the single system. The effect of initial concentration on recovery of Cu(II) from loaded adsorbent decreases up to 60 mg/l where about 68% recovery was found. The maximum recovery for Cu(II) was found to be at an adsorbent dosage in the range 15-35 g. As the initial concentration of Cu(II) increases, the retention of metal on MFLP increases. The data collected are verified with the kinetic studies. The results suggested favorable removal efficiency of copper and chromium from waste water using MFLP.
Sarathi R; Sheeba N. L.; Selva Esakki E; Renuga Devi L; Meenakshi Sundar S
Abstract
Water pollution by organic pollutants is an ever increasing problem for the global concern. The present study is aimed at synthesizing Titanium di oxide nanoparticles under two different concentrations of Zinc as dopant material. The synthesized nanoparticles are used as a catalyst in degrading malachite ...
Read More
Water pollution by organic pollutants is an ever increasing problem for the global concern. The present study is aimed at synthesizing Titanium di oxide nanoparticles under two different concentrations of Zinc as dopant material. The synthesized nanoparticles are used as a catalyst in degrading malachite green dye an organic pollutant. The morphological studies of zinc doped Titanium di Oxide nanoparticles were carried out using different spectroscopic and microscopic tools. From the XRD Spectra average crystallite size, lattice parameters, volume of unit cell are studied. The bandgap of the material was found by using UV-Vis absorbance Spectroscopy. Fourier Transform Infrared Spectroscopy confirms the functional group present in the sample. Under light illumination, metal oxide nanoparticles act as a good photocatalyst in converting a harmful material into a less harmful one. In this aspect the malachite green dye prepared from river water is degraded under the illumination of visible light. Almost above 95% of degradation in 60 min is observed reporting the Zinc doped Titanium dioxide as an eminent photocatalyst.
Pranjal Saikia; Ananta Saikia; Binoy Kumar Saikia
Abstract
Removal of heavy metals from waste water is a need of the hour. Titanium dioxide (TiO2) nanoparticles were functionalized using succinic anhydride (SA) and adsorption of copper (II) on SA functionalized TiO2 nanoparticles (TiOSA) was carried out. The adsorption of Cu (II) on TiOSA was estimated with ...
Read More
Removal of heavy metals from waste water is a need of the hour. Titanium dioxide (TiO2) nanoparticles were functionalized using succinic anhydride (SA) and adsorption of copper (II) on SA functionalized TiO2 nanoparticles (TiOSA) was carried out. The adsorption of Cu (II) on TiOSA was estimated with respect to pH, contact time and adsorbent dose. The study confirms the best removal of Cu (II) using the said adsorbent is at pH 8. The Cu (II) concentration can be reduced to less than 1.1 mg/L at contact time of 180 min with initial 15 mg/L Cu (II) concentration using adsorbent dose of 0.6 g/50 mL. The study reveals that the adsorption process preferably follows the Langmuir isotherm model. Also, the thermodynamic parameters like entropy change (∆S°), enthalpy change (∆H°) and free energy change (∆G°) were calculated for the adsorption process. The pseudo-second order kinetic model was found to be better fitted to the adsorption.
Marjan Tanzifi; Mohsen Jahanshahi; Majid Peyravi; Soodabeh Khalili
Abstract
Dye-containing wastewater is a major pollutant that can irreversibly damage the environment. Ultrafiltration membrane technology combined with photocatalysis is used for treatment of dye-containing solutions. To remove dye pollution, Methylene blue (MB) and Congo red (CR), graphitic carbon nitride (CNG) ...
Read More
Dye-containing wastewater is a major pollutant that can irreversibly damage the environment. Ultrafiltration membrane technology combined with photocatalysis is used for treatment of dye-containing solutions. To remove dye pollution, Methylene blue (MB) and Congo red (CR), graphitic carbon nitride (CNG) and its zirconium dioxide nanocomposite (CNGZ) were used in the photocatalytic dynamic membrane system in both self-forming and pre-coated modes under household LED light. The filtration results of the self-forming membrane showed that the pure CNG- and nanocomposite-based photocatalytic membrane systems were more efficient for MB and CR dyes removal than the photocatalytic system in batch mode. In addition to improving dye molecule removal efficiency, adding the photocatalyst to the PES membrane also significantly increased water flux. Moreover, the respective MB and CR rejection rates were 29% and 47% for the pure PES membrane and 89% in 120 min and 100% in 80 min for the CNGZ-based photocatalytic membrane. This suggests that the photocatalytic membrane system is a more effective dye pollution remover than the pure PES. For comparison, the pre-coated dynamic membrane system used for MB dye removal was good for removing 98.6% within 20 min. The results suggest that CNGZ-based photocatalytic dynamic membrane is a promising technology for increasing dye molecules removal efficiency and flux in remediation of dye-containing wastewater.
Moksh Tandon; Akshita Gupta; Anupreet Kaur
Abstract
It is unquestionable that the employment of nano technology in every enterprise depicts a future for sustainable development due to the cheap and clean availability of nano materials. Evidently the researchers have largely centered on the blessings of the nano materials in cosmetics and food industries ...
Read More
It is unquestionable that the employment of nano technology in every enterprise depicts a future for sustainable development due to the cheap and clean availability of nano materials. Evidently the researchers have largely centered on the blessings of the nano materials in cosmetics and food industries failing to center the negative effects it can impose on human fitness and environment. Titanium dioxide (TiO2) is one such nano particle that despite its elite properties is responsible for generation of oxidative stress. This review compiles some significant research carried out for the assessment of accelerated oxidative stress markers and the presence of Titania traces in human samples and sea organisms manifesting how they are damaging the living mechanisms. The elimination of the nanoparticles into the environment somehow advances towards land and water contaminating the soil, rivers and oceans having a derogatory effect on the natural running phenomena of soil organisms, sea algae and mussels. This review presents the latest findings and indicates making some strategies for reducing the use of the nano materials to a significant but limited amount making sure that it is not liable to any impairment to the humans and the surroundings.
Sankara Rao Miditana; Siva Rao Tirukkovalluri; Manga Raju Imandi; Bangaru Babu A; Ramesh Babu A
Abstract
TiO2-based nanomaterials are very effective for water and air purification and act as good antibacterial agents due to their unique physicochemical properties. TiO2 is a promising nanocatalyst because of its non-toxicity, chemical stability, and low cost. The wide band gap and rapid electron-hole recombination ...
Read More
TiO2-based nanomaterials are very effective for water and air purification and act as good antibacterial agents due to their unique physicochemical properties. TiO2 is a promising nanocatalyst because of its non-toxicity, chemical stability, and low cost. The wide band gap and rapid electron-hole recombination limit its performance which can be overcome by doping with metals and non-metal ions. Metal doping improves the trapping of electrons to inhibit electron-hole recombination and non-metal doping reduces the bandgap of TiO2. These doped TiO2 materials can be synthesized by different routes like the Sol-gel method, hydrothermal method, precipitation method, impregnation method, etc. Among these, the Sol-gel method is reported as the best and most accurate for the synthesis of TiO2 particles in the nano scale range. Because it allows the incorporation of dopant ions at the molecular level with homogeneity and high chemical purity. The structural, morphological, and optical properties of as-synthesized TiO2 nanocatalysts can be well characterized by XRD, SEM, EDX, FT-IR, UV Vis-DRS, TEM, BET, and PL. In this review article, we would like to discuss the advantage of the Sol-gel method over other preparative methods of TiO2 nanomaterials and experimental techniques related to their characterization.
Sathyavathi Ravulapalli; RAVICHANDRA KORASAPATI; Jyothi Lankipalli
Abstract
We report an Environmental-friendly method for the synthesis of Au-Ag alloy nanoparticles (ANPs) by using Anethum graveolens fresh leaf extract as a reducing and stabilizing agent. The precursor solutions of Au (HAuCl4: 3H2O), Ag (AgNO3) and leaf extract were mixed by varying molar ratios and heated ...
Read More
We report an Environmental-friendly method for the synthesis of Au-Ag alloy nanoparticles (ANPs) by using Anethum graveolens fresh leaf extract as a reducing and stabilizing agent. The precursor solutions of Au (HAuCl4: 3H2O), Ag (AgNO3) and leaf extract were mixed by varying molar ratios and heated with continuous stirring at 70℃ for an hour leads a formation of Au-Ag ANPs with different atomic compositions. The periodic observation of colour changes indicated the formation of Au-Ag ANPs and got confirmed by the measurement of UV-Vis spectroscopy. The synthesized Au-Ag ANPs were characterized for morphological and elemental composition using Transmission Electron Microscopy (TEM) in conventional and scanning TEM (STEM) mode. The TEM image analysis shows that the synthesized Au-Ag ANPs were found to be in spherical shape with a broad size distribution with a mean size of 23 ± 18 nm. The energy dispersive X-ray (EDX) spectrometry in the STEM mode confirms the formation of Au-Ag ANPs . To show that these biosynthesized Au-Ag ANPs can be used as SERS (Surface Enhanced Raman Scattering) substrates, we carried out SERS studies using Crystal Violet (CV) and Rhodamine 6G (R6G) as test molecules by using 514.5 nm laser excitation wavelength. The detection level achieved was 50µM of CV and R6G, which would lead to exploring biosensing applications.
Karthiga Rajendaran; Karthikarani Saravanan
Abstract
The green fabricated photocatalyst is promising material and could be applied for waste-water remediation and other ecological applications.Hibiscus floral extract surface modified Ni doped ZnO (HFNZO) was obtained by simple co-precipitation. The flowers have secondary metabolites such as phenolic compounds ...
Read More
The green fabricated photocatalyst is promising material and could be applied for waste-water remediation and other ecological applications.Hibiscus floral extract surface modified Ni doped ZnO (HFNZO) was obtained by simple co-precipitation. The flowers have secondary metabolites such as phenolic compounds named as flavonoids; tannins are turned to be the reluctant to synthesize Ni/ZNO nanoparticles from the precursor. The prepared nanoparticles were examined by various characterization for their optical, structural and surface morphology properties was determined using Uv-Drs, FTIR, XRD, SEM, TEM, EDX, and XPStechniques. Absorption spectral shift of visible light region (red shift) and band gap reduction for ZnO (ZO), hibiscus modified ZnO (HFZO) and hibiscus surface modified Ni doped ZnO (HFNZO) properties were studied and shows a reduction in band gap of the nanoparticles from 3.0eV – 1.65 eV. Results obtained from XRD analysis shows that the synthesized HFNZO nanoparticles has a particle size of about 24.85 nm which is also confirmed by TEM analysis. A 98% visible-light-mediated degradation of the aqueous Rose aniline hydrochloride (RA) of 20 µM solution containing HFNZO of 0.05 g/L nanoparticles has achieved within 90 min. It follows pseudo first order Kinetic and the mechanism of generation of hydroxyl group due to flower extract surface modification and doping has been explained.
Ghader Hosseinzadeh
Abstract
In the current study, for the first time, an innovative hydrothermal method was proposed for the synthesis of TiO2/WO3 heterojunction nanocomposite from the combination of TiO2 nanorod, and WO3 nanoflakes. Because of environmental issues arising from the vast use of insecticides, this nanocomposite photocatalyst ...
Read More
In the current study, for the first time, an innovative hydrothermal method was proposed for the synthesis of TiO2/WO3 heterojunction nanocomposite from the combination of TiO2 nanorod, and WO3 nanoflakes. Because of environmental issues arising from the vast use of insecticides, this nanocomposite photocatalyst was applied for the first time for photocatalytic degradation of Nitenpyram insecticide under visible light irradiation. The prepared nanocomposite was fully characterized by XRD, FESEM, DRS, PL, and Mott-Schottky analysis. The results revealed that the heterojunction sample had the best photocatalytic performance. The enhanced photocatalytic activity of this heterojunction is attributed to the decrease of the charge carrier’s recombination rate and enhanced visible light harvesting. Moreover, based on the radical trapping experiments and Mott-Schottky calculations, hydroxide radical was determined as the main active species for decomposition of Nitenpyram insecticide, and type II charge transfer mechanism was revealed to be responsible for the enhanced photocatalytic performance, which charge transfer between the two semiconductors results in the decreasing of the charge carrier’s recombination rate.
Latha Vatchalan; Pandiselvam S.
Abstract
Paper industries will be using a different kind of dyes for producing various kinds of paper. Rhodamine–B (Rh-B) dye is one of the major sources of color effluents from textile and paper dyeing industries, and they cause long-term effects for on an aquatic environment. So this work mainly focused ...
Read More
Paper industries will be using a different kind of dyes for producing various kinds of paper. Rhodamine–B (Rh-B) dye is one of the major sources of color effluents from textile and paper dyeing industries, and they cause long-term effects for on an aquatic environment. So this work mainly focused on the synthesis of carbon nanoparticles from neem leaves, characterization and its adsorption and photocatalytic action against Rh-B dye. In this study, Carbon nanoparticles (C NPs) from neem leaves were synthesized for adsorption and photo catalytic degradation of Rh-B dye used in paper industries. The synthesized carbon NPs were characterized by the powder X-Ray Diffraction and Scanning Electron Microscopy. The adsorption and photocatalytic properties of Ccarbon NPs were examined for 1 hour by studying the degradation of the Rh-B dye at every 5 minutes time interval through UV-Visible spectrophotometer. The results obtained shown that carbonC NPs acts as better adsorbents than as photo catalysts.
Abbas Ahmadi; Mohammad Hossein Sarrafzadeh; Maryam Mohamadi; Zeinab Mahdigholian; Akram Hosseinian
Abstract
< p>Membrane hybrid processes represent innovative separation technologies in which each technique complements the advantages and overcomes the challenges of the other. Dye removal from wastewater is an application for which membrane hybrid processes are widely applied. The focus of this study ...
Read More
< p>Membrane hybrid processes represent innovative separation technologies in which each technique complements the advantages and overcomes the challenges of the other. Dye removal from wastewater is an application for which membrane hybrid processes are widely applied. The focus of this study is also on development of a membrane hybrid process for dye removal from wastewater. Different proportions of NH2-MIL125(Ti) were embedded in a PSf polymeric membrane through the phase inversion method and the membrane performance was evaluated for the degradation of a Methylene Blue dye under three different light conditions of dark environment, UV and visible light irradiation. The synthesized membranes were characterized by FTIR, XRD, and FE-SEM measurements. NH2-MIL125(Ti) nanoparticles were successfully entrapped in the PSf membrane through a simple phase inversion method and addition of NH2-MIL125(Ti) to the PSf membrane resulted in the improvement of membrane porosity. Up to 60% of dye degradation was observed with the 1% NH2-MIL125(Ti)/PSf nanocomposite membrane after 300 minutes of UV light irradiation. Degradation kinetics followed a pseudo first order model, evidence of possible changes in the membrane properties upon irradiation with simulated solar radiation.
VIJAYALAKSHMI RADHAKRISHNAN
Abstract
Copper oxide nanoparticles are prepared adopting green synthesis route by using Aloe vera plant extract instead of synthetic and polymeric stabilizing agents in mild alkaline aqueous conditions. The synthesised CuO nanoparticles (CuO nps) are characterised by Powder XRD and HR-TEM measurements. Using ...
Read More
Copper oxide nanoparticles are prepared adopting green synthesis route by using Aloe vera plant extract instead of synthetic and polymeric stabilizing agents in mild alkaline aqueous conditions. The synthesised CuO nanoparticles (CuO nps) are characterised by Powder XRD and HR-TEM measurements. Using the as –synthesized CuO nps and reduced graphene oxide (rGO), nanocomposites comprising CuO nps- rGO are prepared by hydrothermal and ultrasonic methods. Nano composites are characterized using Powder XRD, HR-TEM and FE-SEM data. The fabricated CuO nps - rGO nanocomposites are coated onto glassy carbon electrode (GCE) for facile detection and electro oxidation of water polluting dyes such as the Ponceau 4R (P4R) and Alizarin Red (AR) using cyclic voltammetry . Electro oxidation of the dyes occurred at appreciably lower oxidation potentials like 0.45 V and 0.6 V for P4R and AR respectively along with the decoloration of the dyes. The absorbance of the analyte dye solutions are measured at intervals of time of progress of electro oxidations. The overall first order rate coefficient values for dye degradations are found out from absorbance time variance data. The results indicate that CuO nps - rGO nanocomposites decorated GCE acted as an efficient electrode surface for sensing and degradation applications for the chosen dye solutions. P4R azo dye degradation response was found to be better than AR anthroquinon dyes.
Mohammad Hossein Sayadi; Elham Chamanehpour; Nazanin Fahoul
Abstract
The widespread use of antibiotics and their subsequent release into the environment has caused concern around the world. Incomplete metabolism releases these chemicals into the environment, and traditional purification systems are unable to remove them. As a result, it lingers in the environment and ...
Read More
The widespread use of antibiotics and their subsequent release into the environment has caused concern around the world. Incomplete metabolism releases these chemicals into the environment, and traditional purification systems are unable to remove them. As a result, it lingers in the environment and is one of the most serious environmental issues confronting public health. The goal of this study was to investigate the possibility of using ultrasonic and titanium dioxide nanoparticles as catalysts for the removal of amoxicillin from aqueous solutions, as well as to figure out the optimal conditions to maximize the efficiency of removal efficiency. Decomposition of amoxicillin in water in the presence of titanium magnetic catalyst with concentrations of 0.1, 0.25, 0.5, 1, and 2.5 g/L and amoxicillin concentrations of 1, 10, 25, 50, and 100 mg/L at different times of 10 to 180 minutes, pHs of 3, 4, 5, 7, 9 and 11, temperatures of 10 to 60 ºC and frequencies of 35, 300, and 700 kHz were examined. At a concentration of 1 g/L catalyst, a concentration of 10 mg/L amoxicillin, a standstill duration of 60 minutes, an acidic pH, a temperature of 40 °C, and a frequency of 35 kHz, the maximum removal of amoxicillin (91.7%) occurred. The use of an ultrasonic method in conjunction with titanium magnetic nanoparticles as an oxidizing agent proved to be a successful tool for lowering amoxicillin concentrations in aqueous media. As a result, advanced oxidation processes, particularly ultrasonic, can reduce pharmaceutical and organic contaminants in the environment.
Munasir Nasir; Yekti Purnama Utami; Nuhaa Faaizatunnisa; Lydia Rohmawati; Evie Suebah; Ahmad Taufiq; Ezza Syuhada Sazali
Abstract
This study aims to determine the effectiveness of the GO- Fe3O4/Psf membrane in filtering water contaminated with dyes and salt. The membrane was prepared using the phase inversion method, with variations in the composition of GO- Fe3O4 (0.25%, 0.50%, 0.75%, and 1.00%), with polysulfone as the polymer ...
Read More
This study aims to determine the effectiveness of the GO- Fe3O4/Psf membrane in filtering water contaminated with dyes and salt. The membrane was prepared using the phase inversion method, with variations in the composition of GO- Fe3O4 (0.25%, 0.50%, 0.75%, and 1.00%), with polysulfone as the polymer material and NMP as a diluent. The dead-end filtration method is used to study the ability to repel dyes and salt molecules in water. Hydrophilicity (surface contact angle test) and morphology (SEM) to confirm the membrane profile. Furthermore, rejection and filtration performance tests were carried out on water contaminated with dye (methylene blue) and water containing salt through salt rejection, flow flux, and UV-VIS tests. The filtration test results showed that the membrane with a composition of 0.75% had a salt rejection percentage of 59.33% (the highest), and the lowest flow flux was 54.42 L.m-2.h-1. The dye filtering results (MB) showed better performance on the same membrane. It has been observed that the permeate is brighter than the other membranes. These results indicate that the membrane with a GO- Fe3O4 concentration of 0.75 wt.% is the most effective compared to other membranes in filtering water. The presence of Fe3O4 nanoparticles increases the efficiency and durability of graphene membranes in salt rejection by increasing the surface charge and selectively adsorbing salt ions.