Synthesis of Nanostructured Anatase Mesoporous Membranes with Photocatalytic and Separation Capabilities for Water Ultrafiltration Process

Abstract

In this work, the nanostructured anatase mesoporous membranes were prepared for water ultrafiltration (UF) process with photocatalytic and physical separation capabilities. A macroporous substrate was synthesized fromα-Al2O3, then a colloidal titania sol was used for the preparation of the intermediate layer. Also, the membrane top layer was synthesized by deposition and calcination of titania polymeric sol on the intermediate layer. The characterization was performed by DLS, TG-DTA, XRD, BET, FESEM, TEM, and AFM techniques. Also, the filtration experiments were carried out based on separation of methyl orange from aqueous solution by a membrane setup with a dead-end filtration cell. Photocatalytic activity of the membranes was evaluated by methyl orange photodegradation using UV-visible spectrophotometer. The mean particle size of the colloidal and polymeric sols was 14 and 1.5 nm, respectively. The anatase membranes exhibited homogeneity, with the surface area of 32.8 m2/g, the mean pore size of 8.17 nm, and the crystallite size of 9.6 nm. The methyl orange removal efficiency by the mesoporous membrane based on physical separation was determined to be 52% that was improved up to 83% by a coupling photocatalytic technique. Thus, the UF membrane showed a high potential due to its multifunctional capability for water purification applications.

Features of silicon– and titanium–polyethylene glycol precursors in sol–gel synthesis of new hydrogels

“…3, 4 and 27-31 for silicon-and titaniumorganic precursors it is conventional to distinguish colloidal and polymeric gelation (the colloidal sol-gel route and the polymeric sol-gel route), and colloidal and polymeric gels, respectively. 30,31,35 In these cases the necessary condition for polymeric gelation is the low water content. 3,4 Hydrolysis and condensation reactions occur simultaneously and reaction rates depend on the type of precursor as well as reaction conditions.…”

“…[32][33][34] However, some papers report the formation of transparent polymeric gels based on alkoxy-titanium precursors. 30,31,35 In these cases the necessary condition for polymeric gelation is the low water content.…”

Fabrication and Characteristics of MacroporousTiO2Photocatalyst

“…Owing to high photocatalytic efficiency, good oxidation capability, stable chemical reaction, low cost, and nontoxicity, titanium dioxide (TiO 2 ) has been applied widely in wastewater treatment [2][3][4], environment purification [5,6], solar energy transfer [7,8], chemical sensing [9,10]. Recently, it was found that incorporation of well-defined porosity of TiO 2 materials could greatly enhance the photoactivity in the area of environmental remediation and energy conversion [11][12][13]. For a variety of practical applications, the fabrication of desired structure with network is important as well as control in grain size, crystallinity, and composition [14][15][16].…”

Effect of Different Calcination Temperatures on the Structural and Photocatalytic Performance of Bi-TiO2/SBA-15

“…To address this issue, much effort has been focused on enhancing the adsorption ability of the catalysts to improve their photocatalytic performance. Well-ordered mesoporous silica materials such as MCM-41 and SBA-15 have been widely used for adsorption, separation and catalysis [17][18][19][20]. SBA-15 is a type of uniform hexagonal pores and high surface area mesoporous material.…”