Influence of chitosan–PEG binary template on the crystallite characteristics of sol–gel synthesized mesoporous nano-titania photocatalyst

Abstract

a b s t r a c tNano-titania is by far, the most studied material for its photocatalytic application in air and water pollution abatement. In this study, we have demonstrated the advantage offered by using a binary template of PEG and chitosan for the sol-gel synthesis of titania. Nano-titania samples were prepared using PEG, chitosan and the binary combination of these two as templates. XRD showed that all synthesized samples preserved the anatase structure. Titania sample prepared on 1% PEG and 3% chitosan as template (P1-C3 titania) possessed spherical shaped particles with an average particle size of 12.3 nm, a surface area of 82.9 m 2 /g and uniform dispersion. DRS UV-Vis spectra indicated that, P1-C3 titania showed blue shift in its absorption profile due to decrease in particle size. Consistent with the characteristics, the P1-C3 titania exhibited the highest photocatalytic activity for the degradation of 4-chlorophenol under UV irradiation, in comparison with all the synthesized photocatalytic systems and Degussa-P25. The chitosan bio template is believed to offer controlled growth of titania through Lewis base type interaction with Ti metallic centers in TiO 2 . Such controlled growth route will be significant in synthesizing custom-made titania for its advanced applications in catalytic processes.

Chitosan-based nanoparticles for survivin targeted siRNA delivery in breast tumor therapy and preventing its metastasis

“…The results suggested that PEG was successfully conjugated to the CS. 32,33 Preparation and characterization of Peg-cs/sirNa nanoparticles Figure 4A shows that nanoparticles were obtained with PEG-CS complexing siRNA. The mean diameter of PEG-CS/ siRNA nanoparticles was 100 nm with the size distribution being relatively narrow.…”

Investigation of Photocatalytic Activity of Chitosan/Poly(vinyl alcohol)/TiO2/Boron Nanocomposites

“…The IBP removal decreased from 98.6% to 76.8% when the initial concentration increased from 10 mg/L to 30 mg/L. The decrease can be ascribed to the saturation of the photocatalytic active sites by higher concentration of substrate and reduction the photons interaction [12,24]. Due to the saturation, the drug molecules cannot easily contact with the photo-induced holes of catalyst [25].…”

“…Chitosan is a linear polysaccharide including amino and hydroxyl functional groups. Immobilizing TiO2 nanoparticles with chitosan could enhance the specific surface area and pore size [3,6,[9][10][11][12][13][14]. Zainal et al [3] showed that TiO2-Chitosan/Glass catalyst was efficient for removing monoazo dye via the combined effect of photocatalysis-adsorption.…”

“…Nawi et al [11] stated that immobilized TiO2/chitosan catalyst had attractive features like long-term stability and super oxidizing agents. Preethi et al [12] demonstrated that the chitosan as bio template offered controlled growth of titanium via Lewis base reaction. As a result, the existence of chitosan is favorable for TiO2 with the potential of increasing the photocatalytic activity via adsorption or via decreasing the recombination rate of electron-hole pairs.…”

Synthesis of Mesoporous TiO2 Induced by Nano-Cellulose and Its Photocatalytic Properties

“…At present, the synthesis of mesoporous TiO2 materials is achieved using techniques including sol-gel (Antonelli and Ying 1995;Yang et al 1998;Gao et al 2007), microemulsion, and hydrothermal synthesis methods (Danumah et al 2001;Wang et al 2005;Wang et al 2007). Using surfactants as a template agent, self-assembly between organic and inorganic species can be generated (Preethi et al 2014).…”