scholarly journals Synthesis and Characterization of TiO2-CaO and TiO2-CaO-Fe2O3 Photocatalyst for Removal of Catechol

Molekul ◽  
2019 ◽  
Vol 14 (2) ◽  
pp. 140
Author(s):  
Candra Yulius Tahya ◽  
Wahyu Irawati ◽  
Karnelasatri Karnelasatri ◽  
Friska Juliana Purba

TiO2-CaO and TiO2-CaO-Fe2O3 photocatalysts have been synthesized through the surfactant-assisted sol-gel method. The catalysts were characterized using XRD, FTIR, SEM-ED Sand BET surface area. XRD pattern showed the formation of anatase TiO2 crystal phase both in TiO2-CaO and TiO2-CaO-Fe2O3. The TiO2-CaO has higher crystallinity than TiO2-CaO-Fe2O3. Based on the peak refinement using Rietveld, there are two peaks identified as Fe2O3 hematite in the sample TiO2-CaO-Fe2O3.  BET surface area analysis showed that the average pore size of TiO2-CaO and TiO2-CaO-Fe2O3 catalysts are 8.04 and 8.41 nm respectively, indicating both catalysts are mesoporous.FTIR spectra show that the vibration of Ti-O, Ca-O, and Ca-TiO2 were observed in both catalysts. SEM images confirm that both catalysts are porous material. The catechol removal using TiO2-CaO and TiO2-CaO-Fe2O3 improved with the increase of catalyst concentration. After 360 minutes of UV radiation, the removal of catechol using TiO2-CaO-Fe2O3 reached 46.0%, 48.3%, and 69.2%, while when using TiO2-CaO, it reached 22.1%, 36.8%, and 57.0% for 0.1 g, 0.15 g, and 0.2 g of catalysts, respectively. The photocatalytic activity of TiO2-CaO-Fe2O3 is not so strong compared to TiO2-CaO catalyst but the catechol adsorption property of TiO2-CaO-Fe2O3 is higher than that of TiO2-CaO catalyst.

Pharmaceutics ◽  
2018 ◽  
Vol 10 (4) ◽  
pp. 179 ◽  
Author(s):  
Shiao-Wen Tsai ◽  
Wen-Xin Yu ◽  
Pai-An Hwang ◽  
Sheng-Siang Huang ◽  
Hsiu-Mei Lin ◽  
...  

Hydroxyapatite (HAp) is the main inorganic component and an essential part of hard bone and teeth. Due to its excellent biocompatibility, bioactivity, and osteoconductivity, synthetic HAp has been widely used as a bone substitute, cell carrier, and therapeutic gene or drug carrier. Recently, numerous studies have demonstrated that strontium-substituted hydroxyapatite (SrHAp) not only enhances osteogenesis but also inhibits adipogenesis in mesenchymal stem cells. Mesoporous SrHAp has been successfully synthesized via a traditional template-based process and has been found to possess better drug loading and release efficiencies than SrHAp. In this study, strontium-substituted hydroxyapatite-CaO-CaCO3 nanofibers with a mesoporous structure (mSrHANFs) were fabricated using a sol–gel method followed by electrospinning. X-ray diffraction analysis revealed that the contents of CaO and CaCO3 in the mSrHANFs decreased as the doping amount of Sr increased. Scanning electron microscopy (SEM) images showed that the average diameter of the mSrHANFs was approximately 200~300 nm. The N2 adsorption–desorption isotherms demonstrated that the mSrHANFs possessed a mesoporous structure and that the average pore size was approximately 20~25 nm. Moreover, the mSrHANFs had excellent drug- loading efficiency and could retard the burst release of tetracycline (TC) to maintain antibacterial activity for over 3 weeks. Hence, mSrHANFs have the potential to be used as drug carriers in bone tissue engineering.


2018 ◽  
Vol 78 (12) ◽  
pp. 2500-2510 ◽  
Author(s):  
Henry H. Mungondori ◽  
Spencer Ramujana ◽  
David M. Katwire ◽  
Raymond T. Taziwa

AbstractThis work investigates the preparation of a magnetically recoverable photocatalytic nanocomposite of maghemite nanoparticles coated with silica and carbon doped titanium dioxide. The novel nanocomposite boasts the advantages of efficient photocatalytic degradation of organic pollutants in water and ease of recovery of the fine particles after water treatment. The photocatalytic nanocomposite was successfully synthesized through a stepwise approach via co-precipitation and sol-gel methods. Characterisation by Fourier transform infrared (FTIR), X-ray diffraction (XRD), transmission electron microscopy (TEM) and energy dispersive spectroscopy (EDS) substantiated the existence of the intended structure of the nanocomposite and the particles were found to be in the size range of 15–22 nm with a quasi-spherical shape. Brunauer–Emmett–Teller (BET) surface area analysis revealed an average surface area of 55.20 m2/g, which is higher than that of commercial TiO2 (Degussa P25, 50.00 m2/g), and an average pore diameter of 8.36 nm. A 5 ppm methylene blue solution was degraded with an efficiency of 96.8% after 3 h of solar irradiation, which was 19.7% greater than using the same photo-catalyst under strict UV light irradiation. Photo-catalysis using these nanoparticles was observed to be very effective. The prepared novel visible light active nanocomposite has great potential for incorporation into water treatment systems because it exhibits good stability and magnetism, as well as high photocatalytic efficiency.


Horticulturae ◽  
2022 ◽  
Vol 8 (1) ◽  
pp. 46
Author(s):  
Wen-Shing Chen ◽  
Wen-Tien Tsai ◽  
Yu-Quan Lin ◽  
Chi-Hung Tsai ◽  
Yao-Tsung Chang

The edible mushroom industry has grown significantly in recent years due to the dietary change and the demand for heathy food. However, the spent mushroom compost (SMC) will be produced in large quantities after the harvest, thus forming an agricultural waste requiring proper management other than dumping or burning. In this work, two types of SMCs with the cultivation of shiitake fungus (SF) and black fungus (BF) were converted into porous biochar products (a series of SMC-SF-BC and SMC-BF-BC) at higher pyrolysis temperatures (i.e., 400, 600 and 800 °C) based on their thermochemical characteristics, using thermogravimetric analysis (TGA). The pore and chemical properties of the resulting products, including surface area, pore volume, average pore size, scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS) and Fourier Transform infrared spectroscopy (FTIR), were studied to correlate them with the most important process parameter. The results showed that the pore properties of the biochar products indicated a significant increase with the increase in the pyrolysis temperature from 400 to 600 °C. The data on the maximal Brunauer-Emmett-Teller (BET) surface area for the biochar products produced at 800 °C (i.e., SMC-SF-BC-800 and SMC-BF-BC-800) were found to be 312.5 and 280.9 m2/g, respectively. Based on the EDS and FTIR, plenty of oxygen-containing functional groups were found on the surface of the resulting biochar products.


MRS Advances ◽  
2017 ◽  
Vol 2 (57) ◽  
pp. 3505-3510
Author(s):  
Jiankai Zhang ◽  
Xiaohong Chen ◽  
Ran Liu ◽  
Huaihe Song ◽  
Zhihong Li

ABSTRACTMagnesium oxide aerogels were made by sol-gel process using magnesium methoxide as precursor, methanol and deionized water as solvent with ethanol supercritical fluid drying. The influences of the different factors on the gel time and the specific surface area of magnesium oxide aerogels were studied, and the structure and morphology were characterized by Scanning Electron Microscopy (SEM), Transmission Electron Microscope (TEM) and X-ray diffraction (XRD), and the Small Angle X-ray Scatter (SAXS) was utilized to determine the fractural structure of the magnesium oxide aerogels. The results show that MgO aerogels belong to the typical mesoporous materials with rich network and highly developed pore structure, and the specific surface area is 904.9 m2/g, the apparent density is 0.055 g/cm3, the average pore size is 19.6 nm. The results of SAXS analysis show that the fractal dimension of the MgO aerogels is 2.32 in high q area which proves the existence of rough surface and pore fractal structure.


2021 ◽  
Vol 11 (9) ◽  
pp. 3994
Author(s):  
Suhdi ◽  
Sheng-Chang Wang

Fine activated carbon (FAC) is prepared from rubber fruit shells (RFS) using two chemical activating agents (ZnCl2 and KOH) and three impregnation ratios (1:3, 1:4, and 1:5). The Brunauer–Emmett–Teller (BET) results show that for a constant impregnation ratio, the ZnCl2 activating agent yields a higher specific surface area than the KOH agent. In particular, for the maximum impregnation ratio of 1:5, the FAC prepared using ZnCl2 has a BET surface area of 456 m2/g, a nitrogen absorption capacity of 150.38 cm3/g, and an average pore size of 3.44 nm. Moreover, the FAC structure consists of 70.1% mesopores and has a carbon content of 80.05 at.%. Overall, the results confirm that RFS, activated using an appropriate quantity of ZnCl2, provides a cheap, abundant, and highly promising precursor material for the preparation of activated carbon with high carbon content and good adsorption properties


In order to create alternative vanadium oxide-supported catalysts for the process of non-oxidative propane dehydrogenation to propylene, we studied the effect of the increased content of vanadium oxide in the V2O5–ZrO2–SiO2 composition on its structure and catalytic properties. Zirconium silicate hydrogel in the form of finished spherical granules with the SiO2 content of more than 50% was prepared by direct sol-gel synthesis from zirconium oxychloride and sodium metasilicate using the droplet coagulation technology. Catalysts were fabricated by impregnation of hydrogel with an aqueous solution of vanadyl sulfate salt, hydrothermal treatment and calcination in air. By using scanning electron microscopy, X-ray diffraction analysis and low-temperature nitrogen adsorption/desorption method, we showed that amorphous samples with a developed mesoporous structure (with the pore diameter of ~6 nm and the specific surface area of ~300 m2 g–1) were formed when the content of the supporting V2O5 on zirconium silicate was 10, 20, 25, and 30 wt.%. In the course of temperature increase in the propane dehydrogenation reaction, the catalyst samples crystallized in the reaction mixture propane–inert gas with the formation of tetragonal zirconia. When the content of V2O5 was 25% or 30%, additional phases of reduced vanadium oxides and traces of the zirconium vanadate phase were formed. After the reaction, the specific surface area of the catalysts decreased significantly and the average pore size of the samples with 25% and 30% V2O5 increased to ~30 nm. The propylene yield reproducibly observed on the samples with 25% and 30% V2O5 was lower than that on the samples with 10% V2O5; however, it remained quite high, which was probably due to the expanded diameter of the pores and the appearance of additional ZrV2O7 sites that are active with respect to the dehydrogenation of light alkane.


2020 ◽  
Vol 21 (1) ◽  
pp. 77
Author(s):  
Putri Nurul Amalia ◽  
Iman Abdullah ◽  
Dyah Utami Cahyaning Rahayu ◽  
Yuni Krisyuningsih Krisnandi

Carbon dioxide (CO2) is a compound that can potentially be used as a carbon source in the synthesis of fine chemicals. However, the utilization of CO2 is still constrained due to its inert and stable nature. Therefore, the presence of a catalyst is needed in CO2 conversion. This study aims to synthesize copper impregnated mesoporous carbon (Cu/MC) as a catalyst for phenylacetylene carboxylation reaction with CO2 to produce phenylpropiolic acid. The synthesis of mesoporous carbon was performed via the soft template method. The as-synthesized Cu/MC material was characterized by FTIR, SAA, XRD, and SEM-EDX. BET surface area analysis of mesoporous carbon showed that the material has a high surface area of 405.8 m2/g with an average pore diameter of 7.2 nm. XRD pattern of Cu/MC indicates that Cu has been successfully impregnated in the form of Cu(0) and Cu(I). Phenylacetylene carboxylation reaction with CO2 was carried out by varying reaction temperatures (25, 50, and 75 °C), amount of catalyst (28.6, 57.2, and 85.8 mg), type of base (Cs2CO3, K2CO3, and Na2CO3), and variation of support. The reaction mixtures were analyzed by HPLC and showed that the highest phenylacetylene conversion of 41% was obtained for the reaction at 75 °C using Cs2CO3 as a base.


2011 ◽  
Vol 382 ◽  
pp. 427-430
Author(s):  
E. Dong ◽  
Long Guan

Since coal gangue can destroy the environment, we aim at improving coal gangue to absorbing material by changing it in different temperature and chemical liquor. Base on the microstructure and the adsorption experiment, we detect microstructure and absorption property of improved coal gangue. The microstructure experiment shows that the average pore size and specific surface area of improved coal gangue appear distinguish obviously as the increasing of chemical liquor pH value and temperature. Absorption experiment shows that the absorption capacity of improved coal gangue decrease as the chemical liquor pH value increase, increase as the temperature increase. The adsorption capacity of improved coal gangue increases with an increase of average pore size and specific surface area.


2011 ◽  
Vol 298 ◽  
pp. 249-252 ◽  
Author(s):  
Li Li Yang ◽  
Jia Wei Bai ◽  
Wen Jie Zhang

TiO2 film was dip-coated on glass substrate by a sol-gel process. Ti(OC4H9)4 was used as the titanium source. Surface morphology, crystallite phase, UV-Vis transmittance spectrum and pore size distribution of TiO2 powder prepared under the same conditions of the film were investigated. Surface of TiO2 film is fairly smooth with very slight roughness. No obvious hole or pore is found on the surface of the film. The strongest diffraction peak situated at 2θ=25.3o is the characteristic of anatase TiO2. The absorption edge of the TiO2 film is around 350 nm, while the transmittance fluctuates between 50% and 90%. The average pore size of the TiO2 particles calculated by BJH method is 23 nm. The total pore volume and specific surface area are 0.16 ml/g and 27 m2/g, respectively.


2019 ◽  
Vol 964 ◽  
pp. 88-96
Author(s):  
Hariyati Purwaningsih ◽  
Slamet Raharjo ◽  
Vania Mitha Pratiwi ◽  
Diah Susanti ◽  
Agung Purniawan

Rice became the main product of agriculture in agrarian countries including Indonesia. Rice husk is a waste of rice as one of the largest silica producers. Silica from rice husks can be used as a source of silica in the manufacture of sodium silicate as an alternative to the formation of mesoporous silica at a low price. In this research, the characterization of mesoporous silica nanoparticle (MSN) MCM-41 from rice husk (rice husk) with sol-gel method followed by hydrothermal treatment. Silica extraction was performed by titrating sodium silica using HCl method until the gel was formed. The mesoporous synthesis was performed with the addition of CTAB. The titration is then carried out using a solution of acetic acid. XRD shows silica with an amorphous structure. The FTIR results show that extraction silica and MSN MCM-41 contain pure silica displayed with Si-O-Si functional groups in the sample. The SEM results show MSN MCM-41 images such as a coral-like structure of agglomerated silica and the higher temperature hydrothermal treatment then it would be the more large size of particles. The material has a hexagonal pore structure such as a honeycomb as characteristic of MCM-41 with a pore size of 2.535 nm which includes mesoporous material. The result of nitrogen adsorption-desorption isotherms shows lower hydrothermal temperature will increase the specific surface area and decrease average pore size, where the best result with surface area value is 825.365 m2/gr and average pore size is 6.10426 nm obtained from process hydrothermal at 85°C.


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