Solvothermal synthesis of hexagonal multi-walled tubular hierarchical structure TiO2 with co-exposed {010} and {101} plane for high photocatalytic activity

Abstract

Amino acid as a green and non-toxic capping agent was used to regulate TiO2 crystal face exposure and morphology replaced common inorganic F− ions. In this paper, the hexagonal multi-walled tubular anatase TiO2 with hierarchical structure exposed to {010} and {101} planes were synthesized by solvothermal method via optimizing the amino acid (glutamine). The microstructure, crystal plane exposure and photocatalytic activity of TiO2 samples were tested comprehensively, and the formation mechanism of hexagonal multi-walled tubular anatase TiO2 was proposed. The {010} active plane exposure ratio was 70.76% thanks to the appropriate ratios of glutamine to SO42− and the band gap reduced to 2.95 eV for better visible region absorption. The degradation rate of the material for MO reached 94.6% within 80 min, which was 9.37 times than the sample without capping agent. Both high surface area and the synergy effect between the {010} and {101} facets contribute to the improvement of photocatalytic activity.