Routes towards catalytically active TiO₂doped porous cellulose

Abstract

Cellulose-TiO 2 nanocomposites have been successfully prepared by non-solvent induced phase separation, either from cellulose solutions in ionic liquids or from cellulose acetate solutions in classical organic solvents followed by deacetylation ("regeneration"). Commercially available titania nanoparticles from gas phase synthesis processes have been used and processed as dispersions in the respective polymer solution. The used TiO 2 nanoparticles have been characterized by means of transmission electron microscopy (TEM) and X-ray diffraction (XRD), and their dispersions in ionic liquids and organic solvents have been evaluated by dynamic light scattering (DLS) and advanced rheology. The intermediate polymer solutions used in the phase separation process have been studied by advanced rheology. The resulting nanocomposites have been characterized by means of scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FT-IR). Special attention has been given to the complex relationship between the characteristics of the phase separation process and the porous structure of the formed nanocomposites. Two catalytic tests, based on the photocatalytic degradation of model organic dyes under UV irradiation, have been used for the characterization of the TiO 2 doped nanocomposites. The proof-of-concept experiments demonstrated the feasibility of photocatalyst immobilization in porous cellulose via phase separation of nanoparticle dispersions in polymer solutions, as indicated by UV-activated dye degradation in aqueous solution.

Factors Affecting the Nonsolvent-Induced Phase Separation of Cellulose from Ionic Liquid-Based Solutions

“…[Emim][OAc] and [Bmim][OAc] water content was ≤1.1% according to supplier specification. Because in our previous works we had demonstrated that traces of water do not hinder cellulose solubilization and do not have a negative impact to the phase separation process, 45 all materials were used as received. Further on, we considered that this may also facilitate the up-scaling if desired.…”

Synthesis of Titanium Oxide Nanostructures in Ionic Liquids

“…The direct synthesis of titania anatase modification on reduced graphene oxide was reported where the applied IL‐anion directly coordinates to the titanium precursors resulting in a TiO 2 ‐RGO hybrid . Also, the incorporation of titania nanoparticles into cellulose‐based materials is facilitated by ILs , …”

“…[83] Also, the incorporation of titania nanoparticles into cellulose-based materials is facilitated by ILs. [84,85] However, a more detailed study of these hybrid materials might exceed the scope of this review. Nevertheless, we are convinced that the potential of ILs in inorganic synthesis is not fully exploited yet and that the presented materials have al-REVIEW ready promising applications in the fields of gas sorption, photocatalysis, and battery application.…”

One-Pot Route towards Active TiO2 Doped Hierarchically Porous Cellulose: Highly Efficient Photocatalysts for Methylene Blue Degradation

“…Furthermore, cellulose is applicable for supporting TiO 2 nanoparticles owing to its good compatibility with TiO 2 nanoparticles. Several types of low-dimensional cellulose materials have been reported, including cellulose nanofibers and films by electrospinning and phase separation method, respectively [ 2 , 13 , 14 , 15 , 16 ].…”