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

Amino acid as a green and non-toxic capping agent was used to regulate TiO 2 crystal face exposure and morphology replaced common inorganic F − ions. In this paper, the hexagonal multi-walled tubular anatase TiO 2 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 TiO 2 samples were tested comprehensively, and the formation mechanism of hexagonal multi-walled tubular anatase TiO 2 was proposed. The {010} active plane exposure ratio was 70.76% thanks to the appropriate ratios of glutamine to SO 4 2− 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.