Synthesis and characterization of iron supported on dendritic fibrous sba-15 for methylene blue photodegradation /
Ros Shazuin Rayyanu Binti Mohd Zaki,
Synthesis and characterization of iron supported on dendritic fibrous sba-15 for methylene blue photodegradation / Ros Shazuin Rayyanu Binti Mohd Zaki - xv, 153 pages : illustrations (some color) ; 30 cm. + 1 CD-ROM
Faculty of Chemical and Process Engineering Technology
Thesis (Master of Science) -- Universiti Malaysia Pahang – 2023
Includes bibliographical references
Photocatalytic degradation of dyes using heterogeneous catalysts has attracted considerable attention in wastewater treatment due to its environmentally friendly, sustainable, and energy-saving. Photocatalytic degradation has been investigated extensively using a variety of catalysts, including Fe-based catalysts. However, Fe-based catalyst tends to agglomerate and form colloidal suspension due to the poor metal distribution, high band gap, and low surface area under light harvesting. These advantages limit the excitation of positive holes and electrons to the conductive and valence bands, reducing the chances of hydroxyl radical production and thus affecting photodegradation efficiency. On the other hand, dendritic fibrous SBA-15 (DFSBA-15) exhibits desirable qualities, including dendrimer silica fibre shape, wide surface area, large pore diameter, and strong basic sites. The utilization of DFSBA-15 as a support material seems promising due to its flexible and adaptable fibrous hierarchical structure and good physicochemical properties. Therefore, this study focuses on the synthesis, characterization, and photocatalytic evaluation of Fe supported on dendritic fibrous type SBA-15 (Fe/DFSBA-15) for methylene blue (MB) degradation. The DFSBA-15 was prepared by modifying SBA-15 into DFSBA-15 using a microemulsion system coupled with the SBA-15 crystal-seed crystallization method, followed by the impregnation of Fe to the synthesized DFSBA-15. The physicochemical properties of the catalysts were evaluated through Transmission Electron Microscopy (TEM), Field-Emission Scanning Electron Microscopy with Energy Dispersive X-Ray Spectroscopy (FESEM-EDX), X-ray diffraction analysis (XRD), Fourier-transform infrared spectroscopy (FTIR), Photoluminescence (PL), and UV-Vis Diffuse Reflectance Spectroscopy (UV-Vis), while the photodegradation experiment was conducted in a photocatalytic reactor under visible light. The results showed that Fe/DFSBA-15 possessed higher performance than Fe/SBA-15, attributed to the fascinating characteristics of DFSBA-15 that allowed a homogenous Fe distribution with a smaller size of Fe, thus strengthening the metal-support interaction. The effect of Fe loadings (3, 5, 10, and 15%) discovered that the optimal photocatalytic performance was achieved by 10Fe/DFSBA-15 attributed to the strong Fe-O-Si interaction, moderate Fe2O3 crystallite size, homogeneous Fe metal dispersion, creation of oxygen vacancies, and lowering band gap energy and recombination rate. The one-factor-at-time (OFAT) study of several parameters, including catalyst dosage (0.1 – 2 g/L), pH (2 – 10), and initial concentration (10 – 50 mg/L), was studied. It was revealed that 1.5 g/L, pH 8, and 10 mg/L resulted in 94.72% MB degradation. The kinetics and isotherm studies revealed that the experimental data best fitted the pseudo-second-order kinetic and Langmuir isotherm indicated that the chemisorption process and reaction rate-controlled methylene blue adsorption onto Fe/DFSBA-15 were influenced by the number of active sites on the catalyst's surface. The optimization of MB degradation (Y, %) was conducted using response surface methodology (RSM) under independent variables of catalyst dosage (X1, 0.5-2 g/L), pH (X2, 6-11), and initial MB concentration (X3, 10-50 mg/L). The optimal conditions were found at X1 = 1.66 g/L, X2 = 9, X3 = 27.50 mg/L, with Y1= 99.54%. The reusability study under optimal conditions demonstrated the ability of 10Fe/DFSBA-15 in four degradation cycles. In short, the 10Fe/DFSBA-15 catalyst showed a remarkable performance in dye degradation and could be a great advantage in various applications such as the advance oxidation process, Fenton reaction, and electrocoagulation.
THE0009636 (Local)
Faculty of Chemical and Process Engineering Technology--Dissertations
Universities and colleges--Dissertations
Theses--Dissertations
Synthesis and characterization of iron supported on dendritic fibrous sba-15 for methylene blue photodegradation / Ros Shazuin Rayyanu Binti Mohd Zaki - xv, 153 pages : illustrations (some color) ; 30 cm. + 1 CD-ROM
Faculty of Chemical and Process Engineering Technology
Thesis (Master of Science) -- Universiti Malaysia Pahang – 2023
Includes bibliographical references
Photocatalytic degradation of dyes using heterogeneous catalysts has attracted considerable attention in wastewater treatment due to its environmentally friendly, sustainable, and energy-saving. Photocatalytic degradation has been investigated extensively using a variety of catalysts, including Fe-based catalysts. However, Fe-based catalyst tends to agglomerate and form colloidal suspension due to the poor metal distribution, high band gap, and low surface area under light harvesting. These advantages limit the excitation of positive holes and electrons to the conductive and valence bands, reducing the chances of hydroxyl radical production and thus affecting photodegradation efficiency. On the other hand, dendritic fibrous SBA-15 (DFSBA-15) exhibits desirable qualities, including dendrimer silica fibre shape, wide surface area, large pore diameter, and strong basic sites. The utilization of DFSBA-15 as a support material seems promising due to its flexible and adaptable fibrous hierarchical structure and good physicochemical properties. Therefore, this study focuses on the synthesis, characterization, and photocatalytic evaluation of Fe supported on dendritic fibrous type SBA-15 (Fe/DFSBA-15) for methylene blue (MB) degradation. The DFSBA-15 was prepared by modifying SBA-15 into DFSBA-15 using a microemulsion system coupled with the SBA-15 crystal-seed crystallization method, followed by the impregnation of Fe to the synthesized DFSBA-15. The physicochemical properties of the catalysts were evaluated through Transmission Electron Microscopy (TEM), Field-Emission Scanning Electron Microscopy with Energy Dispersive X-Ray Spectroscopy (FESEM-EDX), X-ray diffraction analysis (XRD), Fourier-transform infrared spectroscopy (FTIR), Photoluminescence (PL), and UV-Vis Diffuse Reflectance Spectroscopy (UV-Vis), while the photodegradation experiment was conducted in a photocatalytic reactor under visible light. The results showed that Fe/DFSBA-15 possessed higher performance than Fe/SBA-15, attributed to the fascinating characteristics of DFSBA-15 that allowed a homogenous Fe distribution with a smaller size of Fe, thus strengthening the metal-support interaction. The effect of Fe loadings (3, 5, 10, and 15%) discovered that the optimal photocatalytic performance was achieved by 10Fe/DFSBA-15 attributed to the strong Fe-O-Si interaction, moderate Fe2O3 crystallite size, homogeneous Fe metal dispersion, creation of oxygen vacancies, and lowering band gap energy and recombination rate. The one-factor-at-time (OFAT) study of several parameters, including catalyst dosage (0.1 – 2 g/L), pH (2 – 10), and initial concentration (10 – 50 mg/L), was studied. It was revealed that 1.5 g/L, pH 8, and 10 mg/L resulted in 94.72% MB degradation. The kinetics and isotherm studies revealed that the experimental data best fitted the pseudo-second-order kinetic and Langmuir isotherm indicated that the chemisorption process and reaction rate-controlled methylene blue adsorption onto Fe/DFSBA-15 were influenced by the number of active sites on the catalyst's surface. The optimization of MB degradation (Y, %) was conducted using response surface methodology (RSM) under independent variables of catalyst dosage (X1, 0.5-2 g/L), pH (X2, 6-11), and initial MB concentration (X3, 10-50 mg/L). The optimal conditions were found at X1 = 1.66 g/L, X2 = 9, X3 = 27.50 mg/L, with Y1= 99.54%. The reusability study under optimal conditions demonstrated the ability of 10Fe/DFSBA-15 in four degradation cycles. In short, the 10Fe/DFSBA-15 catalyst showed a remarkable performance in dye degradation and could be a great advantage in various applications such as the advance oxidation process, Fenton reaction, and electrocoagulation.
THE0009636 (Local)
Faculty of Chemical and Process Engineering Technology--Dissertations
Universities and colleges--Dissertations
Theses--Dissertations