Rutile TiO2 nanowires on anatase TiO2 nanofibers: a branched heterostructured photocatalysts via interface-assisted fabrication approach

Changhua Wang; Xintong Zhang; Changlu Shao; Yanli Zhang; Jikai Yang; Panpan Sun; Xueping Liu; Hong Liu; Yichun Liu; Tengfeng Xie; Dejun Wang

doi:10.1016/j.jcis.2011.07.035

Rutile TiO2 nanowires on anatase TiO2 nanofibers: a branched heterostructured photocatalysts via interface-assisted fabrication approach

J Colloid Interface Sci. 2011 Nov 1;363(1):157-64. doi: 10.1016/j.jcis.2011.07.035. Epub 2011 Jul 21.

Authors

Changhua Wang¹, Xintong Zhang, Changlu Shao, Yanli Zhang, Jikai Yang, Panpan Sun, Xueping Liu, Hong Liu, Yichun Liu, Tengfeng Xie, Dejun Wang

Affiliation

¹ Centre for Advanced Optoelectronic Functional Materials Research, Key Laboratory for UV-Emitting Materials and Technology of Ministry of Education, Northeast Normal University, 5268 Renmin Street, Changchun 130024, People's Republic of China.

PMID: 21820128
DOI: 10.1016/j.jcis.2011.07.035

Abstract

A water-dichloromethane interface-assisted hydrothermal method was employed to grow rutile TiO(2) nanowires (NWs) on electrospun anatase TiO(2) nanofibers (NFs), using highly reactive TiCl(4) as precursor. The water-dichloromethane interface inhibited the formation of rutile NWs in water phase, but promoted the selective radial growth of densely packed rutile NWs on anatase NFs to form a branched heterojunction. The density and length of rutile NWs could be readily controlled by varying reaction parameters. A formation mechanism for the branched heterojunction was proposed which involved (1) the entrapment of rutile precursor nanoparticles at water-dichloromethane interface, (2) the growth of rutile NWs on anatase NFs via Ostwald ripening through the scavengering of interface-entrapped rutile nanoparticles. The heterojunction formed at anatase NF and rutile NW enhanced the charge separation of both under ultraviolet excitation, as evidenced by photoluminescence and surface photovoltage spectra. The branched TiO(2) heterostructures showed higher photocatalytic activity in degradation of rodamine B dye solution than anatase NFs, and the mixture of anatase NFs, and P25 powders, which was discussed in terms of the synergistic effect of enhanced charge separation by anatase-rutile heterojunction, high activity of rutile NWs, and increased specific area of branched heterostructures.