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 ...
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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.
Shirish Sadashiv Pingale; Shobha Vasant Rupanar; Manohar Chaskar
Abstract
The present study reports one step green synthesis of silver nanoparticles using Gymnema sylvestre aqueous extract at room temperature and their usage in the photodegradation of methyl orange dye. The silver nanoparticles are synthesized using an aqueous extract of stem and root of Gymnema sylvestre. ...
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The present study reports one step green synthesis of silver nanoparticles using Gymnema sylvestre aqueous extract at room temperature and their usage in the photodegradation of methyl orange dye. The silver nanoparticles are synthesized using an aqueous extract of stem and root of Gymnema sylvestre. UV-Visible spectral analysis showed absorbance peak at 430 nm with special reference to the excitation of surfaces plasmon vibration by silver nanoparticles. FT-IR analysis of nanoparticles reveals the presence of molecular functional groups such as amides, phenolic compounds, and carboxylic acid. These phytochemicals act capping and stabilizing agents for silver nanoparticles. EDAX elemental analysis shows the presence of silver as the main element in synthesized nanoparticles. The average crystalline size of silver nanoparticles was found to be 25.3 nm and 9.97 nm for Stem-AgNPs and Root-AgNPs respectively by Scherer formula. XRD patterns also suggest the occurrence of crystalline silver ions. Further, photocatalytic degradation of methyl orange was measured spectrophotometrically by using silver nanoparticles as nanocatalyst under solar light effect. The results revealed that biosynthesized silver nanoparticles using G. sylvestyre was found to be notable in degrading methyl orange dye under the influence of sunlight.