Biomimetic synthesis of titania with chitosan-mediated phase transformation at room temperature

Abstract

We have demonstrated the glucan polymer-mediated syntheses of titania at room temperature, which is an energy-conserving and environmentally benign synthetic pathway. Wormhole-like particles (both rutile and anatase) with high surface areas and quasi-sphere-shaped particles (anatase) were obtained for chitosan, sodium alginate and cellulose, respectively. Particularly, we have observed the phase transformation from anatase to rutile in the chitosan-mediated titania process; the experimental results revealed a distinct dependence of the phase transformation on the protonation level of the amino groups in chitosan. The obtained results suggest that different charged groups of glucan polymers strongly impact on the size, shape and polymorph of the obtained titania particles, which might provide new insights into in vitro bio-enabled titania formation and pave the way for further studies of titania phase transformations.