Behavior of Silica Nanoparticles Synthesized from Rice Husk Ash by the Sol–Gel Method as a Photocatalytic and Antibacterial Agent (original) (raw)
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Synthesis of silica nanoparticles from rice husk ash
Science and Technology Development Journal, 2018
Silica nanoparticles (SiO2 NPs) were synthesized from rice husk ash (RHA) by chemical treatment and calcination. The size of SiO2 NPs evaluated by transmission electron microscope (TEM) was of 20 - 50 nm and the size distribution of SiO2 NPs measured by dynamic laser scattering (DLS) was of Gaussian mode. The X-ray diffraction (XRD) pattern with only one peak at 2θ ~ 220 confirmed the amorphous phase of SiO2 NPs. The Fourier transform infrared (FTIR) and energydispersive X-ray (EDX) spectra were also used to evaluate the functional groups and the purity of SiO2 NPs. The SiO2 NPs powder with high purity could be suitably produced by calcination of acid treated RHA at 7000C for 2h. The obtained SiO2 NPs product can be potentially used for numerous purposes of application, especially as filler in paints.
Synthesis of silica nanoparticles from Vietnamese rice husk by sol–gel method
Nanoscale Research Letters, 2013
Silica powder at nanoscale was obtained by heat treatment of Vietnamese rice husk following the sol–gel method. The rice husk ash (RHA) is synthesized using rice husk which was thermally treated at optimal condition at 600°C for 4 h. The silica from RHA was extracted using sodium hydroxide solution to produce a sodium silicate solution and then precipitated by adding H2SO4 at pH = 4 in the mixture of water/butanol with cationic presence. In order to identify the optimal condition for producing the homogenous silica nanoparticles, the effects of surfactant surface coverage, aging temperature, and aging time were investigated. By analysis of X-ray diffraction, scanning electron microscopy, and transmission electron microscopy, the silica product obtained was amorphous and the uniformity of the nanosized sample was observed at an average size of 3 nm, and the BET result showed that the highest specific surface of the sample was about 340 m2/g. The results obtained in the mentioned meth...
Chemical Engineering Research Bulletin
Preparation, characterization and utilization of TiO2-SiO2 as photocatalyst for methyl violet (MV) decolorization has been conducted. In this research, preparation of TiO2-SiO2 was developed based on natural renewable silica source; rice husk ash (RHA) via a sol-gel technique. The composite was formed by the dispersing of titanium isopropoxide as titania precursor into the gel of silica followed by aging, drying and calcination. The TiO2-SiO2 sample was characterized by powder X-ray diffraction (XRD), diffuse reflectance-UV Visible spectrophotometric analysis (DRUV-Vis), gas sorption analyzer and Scanning electron micrograph (SEM) before its utilization as photocatalyst in methyl violet photooxidation. As comparison to the physicochemical character study, the synthesis of TiO2-SiO2 by using tetraethyl ortosilicate (TEOS) was performed as a confirmation. Result showed that prepared TiO2-SiO2 has the character similar to TiO2-SiO2 as synthesized by TEOS precursor. The formation of cry...
Production and characterization of silica nanoparticles from rice husk
Advanced Materials Letters, 2018
The rice process generates a large amount of husk, which can become an environmental contaminant if it does not receive an adequate management. Because rice husk is a natural source of silica, in this work silica nanoparticles were obtained as an alternative use for this residue. The synthesis was carried out with the incineration, acid leaching process, and particle size reduction through high-energy mechanical ball milling. For its characterization, thermal, chemical, morphological, structural and superficial area analyses were performed with thermogravimetric analysis, X-ray fluorescence method, scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and Nitrogen adsorption/desorption isotherm techniques. The results indicated that between 150-450°C the organic material of the rice husk was released, and above 550°C was obtained ash rich in silica. The silica purity was effectively increased to 98.48%, through acid leaching with acid nitric. The reduction of particle size by mechanical milling at 600 rpm for 3 h was achieved up to nanometer size. Most of the nanoparticles were spherical with a diameter between 14 and 28 nm. Silicon oxide was the principal structural phase of the nanoparticles corroborated by the broad peak corresponding to the (101) plane shown by XRD pattern. A substantial increase of two magnitude orders of the specific surface area of nanoparticles was reached in comparison with particles without milling. The nanosilica particles obtained from rice husk can be used for the production of high-performance silicon or they can be also used as supplementary cementitious materials.
Applied Water Science, 2024
In this current study, magnetized TiO 2-supported SiO 2 nanoparticles, synthesized from rice husk, was applied as a photocatalyst to degrade methylene blue dye (MBD) in aqueous solution using LED lamp as light source. The effects of MBD initial concentration, TiO 2 loading, pH and illumination time on the degradation efficiency of the photocatalyst on MBD was investigated using Box-Behnken design as the experimental design tool. Photocatalyst was characterized by Fourier transform infrared, scanning electron microscopy, energy-dispersive X-ray, thermogravimetric analysis and Brunauer-Emmett-Teller. At optimum predicted point where MBD initial concentration, TiO 2 loading, pH and illumination time were 10 ppm, 15%, 6 and 75 min, respectively, the predicted and experimental percentage of MBD removed were 97.66% and 96.89%, respectively. Correlation coefficient and ANOVA justified high significance of the developed model for prediction. Experimental data fitted excellently into pseudo-second-order kinetic model. The temperature effect revealed optimum MBD photocatalytic degradation at 50 °C by TiO 2 /mRH-SNP. Characterization revealed the effects of magnetization and TiO 2 addition on the synthesized SiO 2 nanoparticles from rice husk. In conclusion, magnetized TiO 2-silica nanoparticles from rice husk could be effectively used to degrade MBD in solution. Keywords Photocatalyst • Methylene blue • Box-Behnken design • Magnetized TiO 2-silica nanoparticles • Rice husk
Synthesis and Characterization of Titania-Rice Husk Silica Composites as Photocatalyst
This article describes the synthesis of titania-silica composites by a sol-gel method using a mixture of silica of rice husk and titanium butoxide sols. Microstructures were examined at calcination temperature in the range of 500 to 700 °C, with temperatures interval of 50 °C. The sintered catalysts were subsequently tested for photodegradationof methylene blue (MB) under ultraviolet and sunlight rays. Physical characteristics were analyzed using X-ray diffraction (XRD), scanning electron microscopy (SEM)/energy dispersive X-ray spectroscopy (EDS), and BrunauerEmmett-Teller (BET). The XRD results did not show the presence of silica crystal phase in each sample. The results showed that the highest BET surface area of samples was obtained at the temperature of 650 °C. In sample calcined 500 °C, the activity of the catalyst on MB was relatively similar in both sunlight and ultraviolet rays. Keywords: rice husk silica; titania; photocatalysis; dye
Silica-tin material has been synthesized by simple sol-gel method using rice husk ash as the source of silica and cetyltrimethylammonium bromide as the surfactant at room temperature. Calcination of the material at 500 • C for 5 h gave nanotubes with external diameter of 2-4 nm and an internal diameter of 1-2 nm. The BET specific surface area was found to be 607 m 2 g −1 . Nitrogen sorption analysis exhibits a type IV isotherm with H3 hysteresis loop. The powder X-ray diffraction pattern showed that the material is amorphous. The photocatalytic activity of the prepared material was studied towards degradation of methylene blue under UV-irradiation. According to the experimental results the silica-tin nanotubes exhibit high photocatalytic activity compared to pure rice husk silica.
Preparation of silica nanoparticles from semi-burned rice straw ash
Powder Technology, 2008
Semi-burned rice straw ash (SBRSA), as waste material provided from gas production unit of rice straw, was used to prepare silica nanoparticles. Box-Behnken statistical experimental design was used to optimize the factors affecting the dissolution efficiency of the silica such as stoichiometry (NaOH:SiO 2 ), reaction time and reaction temperature, and to determine the optimum conditions for the extraction process. X-ray diffraction (XRD) and Scanning Electron Microscope (SEM) have been used for the characterization of the SBRSA while UV/VIS/NIR Spectrophotometer was used to measure the concentration of the silica in the solution. The results show that the main constituent of SBRSA is silica (62%). Statistical design shows that the dissolution efficiency was in an agreement with the generated model and the experimental results. It is observed that the dissolution efficiency of silica was increased by increasing leaching temperature, time and stoichiometery. At stoichiometric value 1 and 2, the dissolution efficiency of silica was increased by increasing leaching temperature and time and did not reach 99% efficiency. By increasing the stoichiometric value up to 3, the dissolution efficiency reaches 99.88% at 100°C and 4 h.
Green Nanotechnology: Harnessing Rice Husk Ash for Nano-Silica and Characterization Insights
International Journal of Enviornment and Climate Change, 2023
In the form of nanoparticles, silica is a significant inorganic component of rice husk. Consequently, it is feasible to extract high purity amorphous silica nanoparticles by straightforward thermochemical processes. So, in this study, an eco-friendly chemical treatment method (Green Synthesis) was used to try and manufacture amorphous silica nanoparticles from rice husk ash. I had done synthesizing silica nanoparticle in Dept. of Soil Science and Agricultural chemistry, TNAU, Coimbatore in the year 2023 and the aim of this study is to characterize the silica nano particle and use it on agricultural crops. Selected region from X-ray diffraction analysis and