Leila Hajiaghababaei; Zahra Farashe; Alireza Badiei; Mohammad Reza Ganjali; Ghodsi Mohammadi Ziarani
Abstract
In this work, polyamidoamine dendrimer G(1.5) supported on SBA-15 nanoporous is used as a novel sorbent for extraction and determination of Pb2+ and Cu2+ ions from environmental water specimens utilizing flame atomic absorption spectrometry. FTIR spectrum and thermal analysis were used to represent the ...
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In this work, polyamidoamine dendrimer G(1.5) supported on SBA-15 nanoporous is used as a novel sorbent for extraction and determination of Pb2+ and Cu2+ ions from environmental water specimens utilizing flame atomic absorption spectrometry. FTIR spectrum and thermal analysis were used to represent the existence of dendrimer groups in the silica framework. The various parameters like pH, concentration of eluent, extraction time, interfering ions on extraction efficiency were studied. Pb2+ and Cu2+ ions were completely extracted at pH= 5-8 after stirring for 5 minutes. The minimum quantity of acid for stripping the ions from SBA- G1.5 was examined and the pre-concentration factor of the technique was 233 for both of ions. Under the optimized conditions the linearity of the technique was within 10-40 ng mL−1 Pb2+ and 2-20 ng mL−1 Cu2+. Detection limits for Pb2+ and Cu2+ were 5.0 and 1.2 ng mL-1 and the relative standard deviations (RSD, %, C=15 ng mL-1, n=5) were 2.9 % and 2.1 %, respectively. There was a good consistency between the measured and added amount of Pb2+ and Cu2+ in spiked distilled water which shows good accuracy of the method. Capability of the method in real sample was tested in various water samples.
Jeba R; Radhika S; Padma C M; Ascar Davix X
Abstract
Multifunctional Zirconia Nanorods performing photocatalysis, anti-bacterial and anti-fungal activities are presented in this article. Tetragonal Zirconia is synthesized by simple co-precipitation method. The synthesized Zirconia is characterized by various characterization methods such as XRD, SEM, EDX, ...
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Multifunctional Zirconia Nanorods performing photocatalysis, anti-bacterial and anti-fungal activities are presented in this article. Tetragonal Zirconia is synthesized by simple co-precipitation method. The synthesized Zirconia is characterized by various characterization methods such as XRD, SEM, EDX, UV-Vis, PL, VSM and TG/DTA analysis. Exploration of powder XRD pattern indicates tetragonal phase. SEM image illustrates rod-shaped morphology. UV-Vis spectra reveal that the synthesized catalyst has wide band gap of about 4.6eV. The emission peaks in the PL spectra reveal the presence of oxygen vacancies in the sample. Room Temperature Ferromagnetism (RTFM) is confirmed from VSM measurements. The performance of Zirconia nanorods in various applications such as photocatalysis, anti-bacterial and anti-fungal activities has been analyzed. t-ZrO2 photo catalyst degrades methylene blue dye with 80% removal efficiency in 180 minutes under UV light irradiation. t-ZrO2 obtained 28mm inhibition zone against Staphaureus for anti-bacterial assessment while Amikacin has 15mm inhibition and obtained 25mm inhibition zone against Candida Albicans for anti-fungal assessment while Nystatin has 20mm inhibition. t-ZrO2 shows superior inhibiting effect against both gram positive and gram negative bacterial pathogens. Owing to its high surface area it exhibits greatest inhibiting effect against fungal strain.
Sarathi R; Meenakshi Sundar S
Abstract
Titanium-di-oxide nanoparticles are synthesized via a microwave-assisted solvothermal route for different pH values. The effect of the acidic and basic nature of the solvent due to the pH value is reflected in the crystalline size of the compound. The purpose of this work is to synthesize Titanium dioxide ...
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Titanium-di-oxide nanoparticles are synthesized via a microwave-assisted solvothermal route for different pH values. The effect of the acidic and basic nature of the solvent due to the pH value is reflected in the crystalline size of the compound. The purpose of this work is to synthesize Titanium dioxide nanoparticles and to observe their application in degrading industrially contaminated water using normal tap water. The crystalline sizes are calculated using XRD analysis and confirmed with HRTEM. The chemical composition and oxidation state are confirmed with XPS studies. Optical properties are carried out with UV-Vis, FTIR, and PL spectra. Photocatalytic studies are carried out to degrade the dye in industrial water. The efficiency of degradation is calculated with the UV-Vis data and formula. The reduction in band gap and high permanence has greatly supported in making it acceptable for photocatalytic activity under visible light. Dependence of time, initial dye concentration, and pH of the dye solution on TiO2 as a catalyst is investigated under the illumination of a visible lamp, and degradation efficiency to the highest of 96.79% has been obtained.
Siavash Fathi; Bagher Aslibeiki; Reza Torkamani
Abstract
In the recent decades, increasing of pollutant in water resources endanger the human life and other living things. Researchers have applied different methods to eliminate the water contaminants. Photocatalytic is one of these methods that have been used widely for wastewater treatment. In this study, ...
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In the recent decades, increasing of pollutant in water resources endanger the human life and other living things. Researchers have applied different methods to eliminate the water contaminants. Photocatalytic is one of these methods that have been used widely for wastewater treatment. In this study, a series of Mn, Fe, Co, Ni, and Cu doped ZnO nanorods were applied as visible-light-activated catalysts for oxytetracycline (OTC) degradation. Characterization of the nanorods was performed using XRD, FE-SEM, UV-Vis, and PL techniques. The results show that photocatalytic activity of the samples highly depends on morphology, size and band gap energy. The UV–Vis spectroscopy indicate that Fe doping has reduced the band gap energy to 2.91 eV. The variation of band gap permits absorption of low energy photons and excitation of valence band electrons. The photoluminescence spectra reveal that doping has an effective role in inhibiting the recombination of electron/hole pairs during photocatalytic process. The Mn-doped sample exhibits significantly increased photocatalytic activity and greater degradation rate constant (k) in comparison with the pure ZnO.
Hessam Jafari; Gholam Reza Mahdavinia; Bagher Kazemi; Shahrzad Javanshir; Samira Alinavaz
Abstract
Abstract: In this project, new magnetic Fucus vesiculosus (m-FV) nanoparticles with a high adsorption capacity of cationic dyes were prepared. To reach a nanocomposite with effective performance, Fucus vesiculosus (FV) was modified using ultrasound. Then, the Fe2+/Fe3+ ions were co-precipitated in situ ...
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Abstract: In this project, new magnetic Fucus vesiculosus (m-FV) nanoparticles with a high adsorption capacity of cationic dyes were prepared. To reach a nanocomposite with effective performance, Fucus vesiculosus (FV) was modified using ultrasound. Then, the Fe2+/Fe3+ ions were co-precipitated in situ to induce magnetic feature to FV particles. Solutions contaminated with the model cationic dyes, methylene blue (MB) and crystal violet (CV), were treated by employing m-FV particles. Study on time of dyes removal showed a fast removing rate of MB and CV, reaching equilibrium at 10 and 5 minutes, respectively. Analysis of experimental kinetic data by the pseudo-first-order and pseudo-second-order models indicated a well-describing of data by the pseudo-second-order model. The isotherm data of adsorption of both cationic dyes on m-FV were modeled and revealed a well-describing with the Langmuir model. According to the Langmuir model, maximum adsorption capacities of 577 mg/g for MB and 1062 mg/g for CV on m-FV observed. Easy recovery, good recyclability, pH-independent property, as well as the high capability in the removal of cationic dyes, the m-FV can be considered an effective and eco-friendly bioadsorbent in the treatment of dye contaminated solutions.
Zahra Hashemi; Mina Shirzadi-Ahoodashti; mohammad ali Ebrahimzadeh
Abstract
Recent developments in nanotechnology lead to draw scientist's interest in green synthesis nanoparticles because of their importance in all fields of sciences. This paper is an overview of Ag nanoparticles biosynthesis (AgNPs) by aerial part of Alcea rosea extract. Synthesis procedures were described, ...
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Recent developments in nanotechnology lead to draw scientist's interest in green synthesis nanoparticles because of their importance in all fields of sciences. This paper is an overview of Ag nanoparticles biosynthesis (AgNPs) by aerial part of Alcea rosea extract. Synthesis procedures were described, with no stabilizers or surfactants. The synthesized AR@AgNPs were characterized using scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction analysis (XRD), and UV-Vis analysis. The UV-Vis spectrum of AR@AgNPs shown a characteristic surface plasmon resonance (SPR) peak at 425 nm. Scanning electron microscope revealed spherical shaped with a diameter range of 10-30 nm. Energy dispersive X-ray spectroscopy analysis demonstrated the peak in silver region confirming presence of elemental silver. Evaluation of the antibacterial and antileishmanial activity of biosynthesized silver nanoparticles was performed. AR@AgNPs exhibit effective antibacterial activity against seven ATCC strains of bacteria and eight strains of drug-resistant bacteria. Also, their activity against leishmaniasis was studied on both promastigotes and amastigotes.
Ananda A; Ramakrishnappa T; Ravishankar T N; Archana S; Shilpa B M; Reddy yadav L S; Jayanna B K
Abstract
In this work, the tetragonal Zirconium oxide (ZrO2) nanoparticles (NPs) were successfully synthesized by solution combustion method using Zirconium (IV) oxynitrate hydrate as the metal precursor and an oxidizer, Basella alba raw extract at 6000C. In this study, natural fuel is used to avoid harmful chemical ...
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In this work, the tetragonal Zirconium oxide (ZrO2) nanoparticles (NPs) were successfully synthesized by solution combustion method using Zirconium (IV) oxynitrate hydrate as the metal precursor and an oxidizer, Basella alba raw extract at 6000C. In this study, natural fuel is used to avoid harmful chemical fuels that may pollute the environment during combustion. The impact of the fuel-to-oxidant molar ratio on the surface morphological features of nanocrystalline zirconia particles has been documented. We investigated the Physico-chemical properties of the ZrO2 NPs via thorough characterizations like XRD, EDS, SEM, TEM, FTIR, UV-Vis, and BET. ZrO2 NPs exhibit perfect photocatalytic degradation activity towards Evans blue, a toxic dye. The influence of contact time, initial dye concentration, and pH were among the independent variables used in the study. The Response Surface Model (RSM) was used to optimize and describe the interdependencies of the different variables. The method was evaluated using the Box-Behnken design (BBD). A second-order polynomial model was used to properly understand the experimental results, and the effectiveness of the chosen model was verified by the strong agreement in determination coefficient values. ZrO2 NPs also exhibit good antibacterial activity on Gram-negative Klebsiella pneumoniae and Gram-positive bacteria, Bacillus subtilis.
Dharamveer Singh; Ashok Kumar Yadav; Anil Kumar; Samsher .
Abstract
In the current study, 25% incorporating PVT hybrid CPC collector double slope solar still is using Al2O3 nanoparticles underwent energy matrices analysis and life cycle conversion efficiency (LCCE). With the aid of an analytical programfed into MATLAB, the analysis is conducted on an annual basis based ...
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In the current study, 25% incorporating PVT hybrid CPC collector double slope solar still is using Al2O3 nanoparticles underwent energy matrices analysis and life cycle conversion efficiency (LCCE). With the aid of an analytical programfed into MATLAB, the analysis is conducted on an annual basis based on the atmospheric conditions in New Delhi. The IMD in Pune, India, provided the input data needed for the numerical computations. The average annual energy output will be calculated using energy and exergy, then evaluated. This will reveal that the average annual yield is 8.5%, the average energy payback time is 16.16%, the average energy payback factor is 13.91%, and the average life cycle cost conversion efficiency is 7.15% higher. Therefore it is obvious the proposed system is better on the basis of following parameters i.e. annual yield, energy matrices such as efficiency of life cycle cost (LCCE), factor of energy payback (EPF), energy payback time (EPT) than previous system. The proposed hybrid system can be met the future requirement of potable water as well as electricity.
Peghah Ghomashi; Amir Charkhi; Mohammad Kazemeini; Taher Yousefi
Abstract
In this study adsorption of fluoride ion from high-fluorine solutions (
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In this study adsorption of fluoride ion from high-fluorine solutions (
EDUARDA REGINA CARVALHO; WILSON TADEU LOPES DA SILVA
Abstract
A sensory system was manufactured and tested to detect carcinogenic organochlorines, such as trihalomethanes (THM), in effluents produced by a biodigestion septic tank. Gold-coated interdigitated microelectrodes were coated with various nanostructured conducting polymers, single or mixed, under different ...
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A sensory system was manufactured and tested to detect carcinogenic organochlorines, such as trihalomethanes (THM), in effluents produced by a biodigestion septic tank. Gold-coated interdigitated microelectrodes were coated with various nanostructured conducting polymers, single or mixed, under different conditions and configurations. Polymer films were assembled by the self-assembly technique and their impedance was analyzed in a frequency range from 1 Hz to 1 MHz. The results of the sensory system, analyzed by the PCA Main Component Analysis, allowed to identify the discrimination of the different samples tested. Good discrimination between sensors was also observed, when PCA's were obtained, in contamination experiments with standard solutions of total trihalomethanes (TTHM), obtaining a total variance (PC1 = 98.02%; PC2 = 1.98%) of the observations. The sensory system based on global selectivity using interdigitated electrode and nanostructured conducting polymers allowed the statistical discrimination of samples. The future expectation is to update the system and implement monitoring of nanostructured sensors based on the reuse of domestic effluents, mainly for agricultural applications or for other purposes, in a sustainable way.
Azita Albouyeh; Afshin Pourahmad; Hassan kefayati
Abstract
Rice husk silica (RHS), an agriculture waste, was used as a silica source for MFI zeolite synthesis. Magnesium oxide (MgO) nanoparticles (NPs) were grown in zeolite substrates using a solid state reaction. The synthesized nanocomposite (NC) was characterized by X-ray diffraction (XRD), scanning electron ...
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Rice husk silica (RHS), an agriculture waste, was used as a silica source for MFI zeolite synthesis. Magnesium oxide (MgO) nanoparticles (NPs) were grown in zeolite substrates using a solid state reaction. The synthesized nanocomposite (NC) was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), diffuse reflectance spectroscopy (DRS) and transmission electron microscopy (TEM) techniques. The BET results demonstrated specific surface area of MgO/RHS-MFI NC was smaller than RHS-MFI zeolite. It was founded that magnesium oxide NPs can be encapsulated into pores of RHS-MFI zeolite. The most principal objective of this research was evaluation of the capability of photocatalytic process of MgO/RHS-MFI zeolite heterogeneous nanocomposite over methylene blue (MB) dye. The results showed the MB degradation reached 80 % under UV light at pH=9. RHS-MFI affected the photocatalytic activity of magnesium oxide due to decrease of recombination rate of the electro-hole in magnesium oxide semiconductor. A plausible oxidation mechanism was also proposed.
Rajitha Beerelli; Padma Suvarna
Abstract
In this current research work, the synthesis of Copper (Cu) doped and Magnesium (Mg) co-doped of BeFiO3 (BFO), i.e BiFe1-xCuxO3 (where; X= 0.1, 0.15 and 0.2 wt.%) and Bi1-yMgyFe1-xCuxO3 (where; Y=0.05, 0.1 and 0.15 wt.%) were prepared by sol-gel method. The obtained samples were analyzed by various characterization ...
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In this current research work, the synthesis of Copper (Cu) doped and Magnesium (Mg) co-doped of BeFiO3 (BFO), i.e BiFe1-xCuxO3 (where; X= 0.1, 0.15 and 0.2 wt.%) and Bi1-yMgyFe1-xCuxO3 (where; Y=0.05, 0.1 and 0.15 wt.%) were prepared by sol-gel method. The obtained samples were analyzed by various characterization techniques including X-ray diffraction (XRD), surface morphology examined by field emission scanning electron microscopy (FE-SEM) and transition electron microscopy (TEM). It was noted that Cu (0.15 wt.%) doped BFO had notable photocatalytic activity for Rhodamine (RhB) dye degradation when exposed to visible light irradiation. In addition to Cu (0.15 wt.%) by adding Mg (0.1 wt.% ) as a co-doping, exhibited higher photodegradation than the pure BFO, Cu-doped BFO (0.1and 0.2 wt.%) and Mg co-doped BFO (0.05 and 0.15 wt.%). Here we reported a new driven photocatalyst by doping of Cu and co-doping of Mg into BFO simultaneously. These played a key role in hampering the recombination of electron-hole pairs hence chance to increase dye degradation performance. These findings could be useful for developing affordable photocatalysts for wastewater purification.
Asmaa A. Abd-Allah Abd-Allah; Yasser M.Z. Ahmed; Said M. El-sheikh; Ahmed O. youssef; Amira M.M. Amin
Abstract
Scientists and researchers from all over the world are paying close attention to the recycling of industrial waste into new materials. Aluminum and zinc sludge powders were gathered from aluminum sheets and big iron manufacturers to be used as starting materials in the synthesis of zinc aluminate nanoparticles. ...
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Scientists and researchers from all over the world are paying close attention to the recycling of industrial waste into new materials. Aluminum and zinc sludge powders were gathered from aluminum sheets and big iron manufacturers to be used as starting materials in the synthesis of zinc aluminate nanoparticles. The XRF, XRD, and DTA examinations were used to characterize the collected sludge powders. The main components of aluminum and zinc sludges, according to the findings, are gibbsite (Al(OH)3) and hydrozincite (Zn5(CO3)2(OH)6), respectively. Without any primary advanced chemical treatments, the collected sludges were used to perform solid-state reaction (SSR) and molten salt synthesis (MSS) at 1100°C. XRD, FTIR, XPS, SEM, and TEM examinations were used to characterize the synthesized samples. Both SSR and MSS deduced pure phase zinc aluminate nanoparticles, with crystallite sizes of 17.4 and 12.7 nm for SSR and MSS samples, respectively. The microstructure of the MSS sample was characterized by a high structure homogeneity, whereas, the high degree of particle aggregation was shown by the SSR sample’s microstructure. The optical properties of the synthesized SSR and MSS samples were studied by using UV-visible and PL spectroscopy. The bandgap energies for SSR and MSS samples were calculated to be 2.78 and 2.48 eV, respectively. These samples are utilized in the photocatalytic degradation of the brilliant cresyl blue dye (BCBD), owing to their tiny bandgap energies and high absorption efficiency. The photocatalytic degradation percent of BCBD reached 94.5% and 86.7% by using MSS and SSR samples, respectively, at the optimum conditions of pH (10), dye concentration (40 mg/l), and sample dose (1 g/l).
Sadhana Jadaun; Usha Sharma; Ringshangphi Khapudang; Saleem Siddiqui
Abstract
Conventional food packaging materials such as plastic or other petro-based polymers provide the necessary strength and barrier qualities, but they are associated with economic and environmental associated hazards. In order to have a material that can effectively compete with petroleum-based plastics, ...
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Conventional food packaging materials such as plastic or other petro-based polymers provide the necessary strength and barrier qualities, but they are associated with economic and environmental associated hazards. In order to have a material that can effectively compete with petroleum-based plastics, the ecofriendly biodegradable biopolymer reinforced bio-nanocomposites from renewable agricultural biomass can be a promising alternative. Lignocellulosic biomass from agricultural wastes can serve as promising raw material for nanocellulose extraction. This review focuses on extensive studies done on pretreatment, isolation of nanocellulose along with their role as reinforcement agent in various biopolymers such as poly-lactic acid, starch, chitosan, alginate and carrageenan. The uniqueness of this review is to give readers a thorough overview of the impact of nanocellulose on the mechanical, barrier, and thermal properties of biopolymeric film. The review will also provide a comprehensive understanding of the supply chain’s elements, their opportunity and constraints for shifting the sustainable production system of cellulose nanocomposites towards circular economy. Efforts have also been made to combine all the recent studies related to key aspects and engineering of nanocellulose biocomposites. The concept of 3D/4D printing technology of cellulose nanocomposites in conjunction with Shape Memory Polymers (SMP) in the domain of commercial development of smart materials and self- folded packages for food applications has also been discussed.
Subramanian Kanchana; Radhakrishnan Vijayalakshmi
Abstract
Photocatalysis mediated by metal nanoparticles is emerging as an effective method for removal of hazardous dye pollutants in natural aquatic bodies. Nanoparticles of Cu, Ni and Ag were synthesized by chemical method using PEG and PVP polymers as capping agents. Experimental photocatalyis was carried ...
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Photocatalysis mediated by metal nanoparticles is emerging as an effective method for removal of hazardous dye pollutants in natural aquatic bodies. Nanoparticles of Cu, Ni and Ag were synthesized by chemical method using PEG and PVP polymers as capping agents. Experimental photocatalyis was carried out in a one pot batch reactor using metal nanoparticle catalysts for degradation of crystal violet (CV), bromocresol green (BCG) and methylene blue (MB) in aqueous solution in the presence of NaBH4 reductant independently under solar and UV irradiations at 25oC. Metal nanoparticles caused the removal of BCG and CV in 90-120 min and MB in 30-60 min. Linear relationship between the irradiation time and the absorbance were recorded and the kinetic plots exhibited pseudo-first order kinetic. The trend of dye degradation among the nanoparticles based on the catalytic efficiency (c) and rate coefficient (k) values was Cu>Ag>Ni. Mineralization experiment indicated 94, 91 and 90% of TOC removal ratio (R) respectively for CV, MB and BCG dyes. Nanoparticles stabilized using PEG demonstrated better catalytic efficiency than those with PVP. Solar irradiation showed superior augmenting effect on the nanoparticle catalysts than the UV irradiation. The electron-hole pair mediated reduction mechanism was proposed as a basis for photocatalytic degradation of dyes.
Aishwarya Singh; bhavani prasad nenavathu
Abstract
Mg(OH)2/CdS heteronanostructures have been successfully synthesized by a novel precipitation method and the synthesis involves three steps. The first step involves the synthesis of Mg (OH)2nanoparticles using homogeneous precipitation method. Then, surface-modifying agent citric acid was used to functionalise ...
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Mg(OH)2/CdS heteronanostructures have been successfully synthesized by a novel precipitation method and the synthesis involves three steps. The first step involves the synthesis of Mg (OH)2nanoparticles using homogeneous precipitation method. Then, surface-modifying agent citric acid was used to functionalise Mg (OH)2. Finally, the cadmium sulfide (CdS) shell was deposited on the surface modified Mg (OH)2by co-precipitation method. The Mg(OH)2/CdS heteronanostructures were characterized using X-ray diffraction, scanning electron microscopy (SEM), transmission electron microscopy (TEM), diffuse reflectance spectroscopy (DRS) and photoluminescence spectroscopy. DRS results showed blue shift of CdS band gap absorption with respect to bulk CdS. XPS results showed evidence for the binding energies of Mg(OH)2, Cd and S. The Mg (OH)2/CdS heteronanostructures was explored as catalyst for sunlight induced photocatalytic degradation of β- naphthol pollutant. The batch of 0.2 mg/ mL of Mg (OH)2/CdS heteronanostructures maintained at pH 8.5 showed maximum photodegradation efficiency (75 ± 2.1 %). Higher photocatalytic degradation efficiency for Mg(OH)2/CdS heteronanostructures could be due to incorporation of CdS and increased reactive oxygen species (ROS) generation. The reusability of the Mg (OH)2/CdS heteronanostructures was also tested, and they show stability for up to three cycles without loss of efficiency.
Jyoti A. Agashe; Dipak R. Tope; sachin S Kushare; Ashok V Borhade
Abstract
Nanocrystalline UV light induced composite CeO2:SiO2 with high surface area and low band gap energy were prepared in order to assess its photocatalytic degradation capacity of target pollutant (mixture of dyes). The complete mineralization of target dye pollutants (30 ppm) occurred within 150 min. when ...
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Nanocrystalline UV light induced composite CeO2:SiO2 with high surface area and low band gap energy were prepared in order to assess its photocatalytic degradation capacity of target pollutant (mixture of dyes). The complete mineralization of target dye pollutants (30 ppm) occurred within 150 min. when CeO2:SiO2 catalyst with optimum loading 0.4 g was used. Overall, the present system is economical, reproducible and highly efficient. Further the comparative study on photocatalytic efficiency of SiO2 and CeO2 was compared with composite CeO2:SiO2. The effect of various operational parameters used in degradation like concentration of dye, amount of photocatalyst and various catalyst has been studied on the rate of reaction. The recyclability of the photocatalyst, CeO2:SiO2 was performed up to four runs. The photodegradation of waste water pollutants was occurred nearly 96 % using CeO2:SiO2 nanoparticles. The removal of waste water pollutants was confirmed by UV spectrophotometer by diminishing the absorbance to zero within 120 min using CeO2:SiO2 nanoparticles. The synthesized catalyst was characterized by various analytical investigative techniques like UV-DRS, FTIR, XRD, SEM, TEM and BET.
Sathiya Sheela D; P Viswanathan; K Kalimuthu; A Vanitha
Abstract
The development of biologically enthused green synthesis of silver nanoparticles (SNPs) has concerned significant global awareness about medical science and disease treatment. This paper discusses the green synthesis of SNPs using organic green sources; here we report a facile bottom-up ‘green’ ...
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The development of biologically enthused green synthesis of silver nanoparticles (SNPs) has concerned significant global awareness about medical science and disease treatment. This paper discusses the green synthesis of SNPs using organic green sources; here we report a facile bottom-up ‘green’ route for the synthesis of SNPs using aqueous leaves extract of Pogostemon speciosus (Benth.) and evaluate its in-vitro anti-inflammatory, antibacterial and photocatalytic activities. The nanoparticles were investigated for the preparation of denaturation particles with PSLASNPs and the evaluation of anti-inflammatory activity with Protein denaturation and HRBC stabilization assays. Later, these PSLASNPs were studied for their potential role in antibacterial activity by well diffusion method, and Photocatalytic activity on degradation of dyes was demonstrated by using dyes Crystal violet, Coomassie blue, and Congo red. At 1000 µg/ml, the PSLASNPs have the greatest prevention of protein denaturation (71.92±1.37%), whilst the stabilization of the HRBC membrane exhibited significant anti-inflammatory action (64.39±1.61 %). The PSLASNPs showed the best antibacterial activity at the concentration of 10 µg/ml against Bacillus subtilis (8.2 mm), followed by Pseudomonas stuberia (6.2 mm) and Escherichia coli (6.4 mm), Staphylococcus aureus (5.3 mm), Staphylococcus gallinarium (4.5 mm) respectively at the same concentrations. Crystal violet, Coomassie blue, and Congo red were used for Photocatalytic activity on the breakdown of dyes. After 35 minutes, the degradation process was determined to be complete by the transformation of the reaction mixture's color to colorless. As a result, the PSLASNPs have anti-inflammatory, antibacterial, and photocatalytic activities.
Ubaithulla Baig A; Vadamalar R; Vinodhini A; Fairose S; Gomathiyalini A; Jabena Begum N; Shaista Jabeen
Abstract
Silver and zinc oxide are well known for both antimicrobial and pro-healing properties. ZnO is a biocompatible and bio-safe material that possesses photo-oxidizing and photocatalysis impacts on chemical and biological species. ZnO nanomaterials can interact chemically as well as physically to exhibit ...
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Silver and zinc oxide are well known for both antimicrobial and pro-healing properties. ZnO is a biocompatible and bio-safe material that possesses photo-oxidizing and photocatalysis impacts on chemical and biological species. ZnO nanomaterials can interact chemically as well as physically to exhibit antibacterial activities. Chemical interactions of the ZnO nanomaterials with bacterial cells lead to the photo-induced production of reactive oxygenated species (ROS), formation of H2O2, and release of Zn2+ ions. In contrast, physical interaction can show biocidal effects through cell envelope rupturing, cellular internalization or mechanical damage. Here, we present a green method using Tridax Procumbens leaf extract to synthesize Ag doped ZnO nanoparticles (NPs) to explore the synergistic antibacterial properties of Ag and ZnO nanoparticles against certain gram positive and gram negative bacterial strains. The newly synthesized Ag doped ZnO NPs were characterized by X-ray diffraction (XRD) to study the crystalline structure, composition and purity. Transmission electron microscopy (TEM), Scanning electron microscopy (SEM) and Dynamic Light Scattering (DLS) technique was used to study particle size, shape, and morphology. The XRD and UV studies confirmed the ZnO phase. The absorbance peak around 618 cm-1 - 749 cm-1 in the FTIR spectrum referred presence of silver. The surface morphological studies also supported the FTIR result. The synthesized sample exhibited enhanced antibacterial activity irrespective of all tested microorganisms than the standard antibiotic used. The maximum size distribution of particle is found to be around 60 nm from the DLS technique.
Neena Anna Kurien; K. V. Divya; Jessyamma Kurian; K. E. Abraham
Abstract
In this work we are suggesting a method to reduce the amount of metal nitrates used in industrial and agricultural applications with the help of photocatalytic effect. Also, the work discusses how the residual amount of metal nitrates in the soil can be made useful through the same effect. Though metal ...
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In this work we are suggesting a method to reduce the amount of metal nitrates used in industrial and agricultural applications with the help of photocatalytic effect. Also, the work discusses how the residual amount of metal nitrates in the soil can be made useful through the same effect. Though metal nitrates like ferric nitrate and nickel nitrate shows characteristic absorption in the UV region, what we observed is an enhancement in this UV absorption when we treated this metal nitrates with Titania Tenorite nanocomposite due to its photocatalytic action. This absorbance enhancement property is an indication of increase in concentration of the metal nitrates in the solution with light irradiation. The increase in M–OH bonds owing to the action of the nanocomposite in the presence of light is the reason by which metal nitrates absorption increases. In precise a tiny amount of metal nitrates is needed for any practical use as it can automatically increase its concentration in presence of the nanocomposite by photocatalytic reaction. This will reduce the disposal of unwanted amount of metal nitrates into the surrounding especially water bodies. Also, the residue amount in the soil can act as UV absorbers. Thus, the combination of the metal nitrates with the nanocomposite can be made used for environmental remediation where the metal nitrates are used in large quantities.
Savita Sihag; Sheetal .; Jitender Pal; Monika Yadav
Abstract
The environmental concern occurs due to the extreme use of synthetic materials that have been fortified to develop innovative, multifunctional, and sustainable materials using copious lignocellulosic biomass. In this present study, work was done on the extraction of nanocellulose from wheat straw, and ...
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The environmental concern occurs due to the extreme use of synthetic materials that have been fortified to develop innovative, multifunctional, and sustainable materials using copious lignocellulosic biomass. In this present study, work was done on the extraction of nanocellulose from wheat straw, and found that wheat straw is an admirable source of cellulose. Chemical processes were used to isolate the cellulose and remove unwanted lignin and hemicellulose from wheat straw followed by sonication, cryo-crushing, and magnetic stirring to achieve nanocellulose. The observed amount of cellulose (36.1%), hemicellulose (30.3%), lignin (17%), and ash content (9.2%) of raw wheat straw. Structural, morphological, and thermal characterization were estimated from FTIR, XRD, FESEM, TEM, DSC, TGA, and AFM for the identification and characterization of extracted cellulose from wheat straw. FTIR showed that the peaks at wavelength 1430.50 cm-1 and 1638.41 cm-1 both show that cellulose is present in the extracted nanocellulose. Extracted nanocellulose was crystalline and had a 68.96% Crystallinity Index. Morphological analysis, FESEM showed that the untreated wheat straw has an irregular porous structure but the extracted nanocellulose has a regular shape having straight fibers connected. TEM analysis showed that the extracted nanocellulose has a spherical shape structure connected, showing the regular shape, the obtained spherical shape regulates the nanocellulose for further applications. Thermal degradation was observed using TGA which shows that the nanocellulose decomposition was observed around 3600C. AFM determination shows a bell-shaped structure on a smooth surface with a particle height of 3.2 nm and the mean roughness of 110.4 nm was obtained from the extracted nanocellulose. Extracted nanocellulose has a particle size of 58.77 nm.
Zahra Mirkazehi; Mohammad Reza Rezaei; Mohammad Sayadi
Abstract
Landfill leachate is the fluid percolating through the landfill and is one of the most important environmental challenges that lead to the contamination of water and soil resources. In this study, magnetic graphene oxide nanoparticles with WO3 (GO-Fe3O4/WO3) were synthesized through the hydrothermal ...
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Landfill leachate is the fluid percolating through the landfill and is one of the most important environmental challenges that lead to the contamination of water and soil resources. In this study, magnetic graphene oxide nanoparticles with WO3 (GO-Fe3O4/WO3) were synthesized through the hydrothermal method to eliminate chemical oxygen demand (COD) from leachate. The obtained products were characterized using X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), Thermogravimetric analysis (TGA), and Vibrating sample magnetometer (VSM) analysis. The influence of various operating parameters, such as initial solution pH, adsorbent dosage, contact time, and temperature, on COD removal was studied. Additionally, kinetic, isotherm, and thermodynamic studies were conducted to evaluate the adsorption capacity of the adsorbent. The results revealed that the maximum adsorption capacity of GO-Fe3O4/WO3 was 2500 mg/g adsorbent at pH 4, a contact time of 90 minutes, an adsorbent dosage of 25 mg g-1, and a temperature below 298 K, respectively. According to the adsorption kinetic fitting results, the experimental adsorption data were well described by the pseudo-second order kinetic with an R2 value of 0.97, and the Freundlich isotherm equation with an R2 value of 0.99. The thermodynamic results indicated that the adsorption was spontaneous and exothermic for COD adsorption. In general, the adsorption process of the synthesized GO-Fe3O4/WO3 nanocomposite revealed that it is highly effective for landfill leachate treatment and has great practical value in leachate treatment.
Najmeh Atoub; Ahmad Amiri; Alireza Badiei; Jahan B. Ghasemi
Abstract
In this study, thiol-functionalized nanostructure silica type MCM-41 was successfully prepared via the facile one-pot hydrothermal method with low amounts of the directing agent. The mesoporous silica indicated a remarkable adsorption behavior toward Pb(II) ions without any interference of the competing ...
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In this study, thiol-functionalized nanostructure silica type MCM-41 was successfully prepared via the facile one-pot hydrothermal method with low amounts of the directing agent. The mesoporous silica indicated a remarkable adsorption behavior toward Pb(II) ions without any interference of the competing ions. The main experimental variables affecting removal efficiency of the adsorbent were examined, and the optimized conditions were achieved as to be 6, 50 mg, and 30 min for solution pH, the adsorbent dosage, and contact time, respectively. The adsorbent was triumphantly used for the removal of Pb (II) ion from real water samples with a notable removal efficiency as 95%. The concentrations of the competitive ions in the solution were about 10 to 100 times more than Pb (II) ions. The results show that other ions had no interfering effect on the removal efficiency of Pb (II) ions. It means that SH-SiO2 has excellent selectivity for Pb (II) ions and is an appropriate candidate for removing Pb (II) ions from the real samples.
Aref Shokri; Safoora Krimi
Abstract
In this study, the TiO2 nanoparticles were supported on Y-type zeolite as a new photocatalyst and used to degrade Acid Red 18 in aqueous media. The nano photocatalyst was synthesized by coprecipitation procedure and characterized by Fourier transfer infrared (FTIR), field emission scanning electron microscopy ...
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In this study, the TiO2 nanoparticles were supported on Y-type zeolite as a new photocatalyst and used to degrade Acid Red 18 in aqueous media. The nano photocatalyst was synthesized by coprecipitation procedure and characterized by Fourier transfer infrared (FTIR), field emission scanning electron microscopy (FE-SEM), and X-ray powder diffraction (XRD). The central composite design (CCD) was employed for experimental design. The effect of operative variables including contact time, photocatalyst dosage and pH were investigated. The ANOVA (analysis of variance) studies displays the second-order regression model and a high determination coefficient value (R2 = 0.9953, R2pred = 0.9642, R2adj = 0.9910) for the destruction of AR18 was obtained. The contour plots were applied to study the shares of each variable and their interactions on the degradation of AR18. The optimal circumstances predicted by the model were as the following: the catalyst concentration at 0.88g/L, pH at 6.5, and contact time in 125 min. In this situation, the predicted and actual dye removal were 98.5% and 96.3%, respectively. The removal of COD (chemical oxygen demand) after 125 min was 53% indicating, the notable performance of photocatalyst in mineralization of AR18.
Mahdieh Chegeni; Mozhgan Mehri; Mehdi Hosseini
Abstract
The MoS2/S-doped graphitic carbon nitride (MoS2/S-g-C3N4) was synthesized by a simple method and applied for methylene blue (MB) removal as an organic pollutant. The structure of MoS2/S-doped graphitic carbon nitride was characterized using FTIR, XRD, SEM, TGA and BET techniques. The accomplishment of ...
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The MoS2/S-doped graphitic carbon nitride (MoS2/S-g-C3N4) was synthesized by a simple method and applied for methylene blue (MB) removal as an organic pollutant. The structure of MoS2/S-doped graphitic carbon nitride was characterized using FTIR, XRD, SEM, TGA and BET techniques. The accomplishment of MoS2/S-doped graphitic carbon nitride as an adsorbent was investigated to removal of MB from aqueous solution. The various parameters were studied such as: pH, initial MB concentration, adsorbent dose, temperature and time. The best findings were obtained at pH=8, 8 ppm MB concentration, 0.05 g MoS2/S-g-C3N4, 30 min and 22 ˚C. The Langmuir isotherm model was adopted with the obtained data. The kinetic studies were showed that the adsorption of methylene blue can be well described by the second-order equation. Maximum adsorption was calculated as 166 mg/g. The degradation of MB was studied by MoS2/S-doped graphitic carbon nitride under Light Emmition Diode (LED). Results showed that the MoS2/S-doped graphitic carbon nitride can enhance photocatalytic activity compared to pure g-C3N4 and MoS2/g-C3N4. The findings confirmed that the MoS2/S-doped graphitic carbon nitride can be applied as an efficient, low-cost adsorbent, and photocatalyst to remove of cationic dyes such as methylene blue.
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