Heterostructure TiO2 polymorphs design and structure adjustment for photocatalysis.

ABSTRACT

Atomic composite-structure materials play an important role in energy generation and storage application fields for their advanced performance. Constructing heterostructured semiconductors is a promising strategy to devise photocatalytic systems with high activity. However, most studied hererostructures are those semiconductors with different materials formed by multi-steps, researches on in-situ formed hererostructure originated from the same precursor are few reported, and the effects of different structure ratios on photocatalytic performance are ambiguous. Here, according to in-situ temperature X-ray diffraction and transmission electron microscope techniques, a nano-sized in-situ formed heterostructure of TiO2 semiconductors with anatase and TiO2-B crystalline structures were designed, their structure ratios were adjusted, the heterostructure interface and photocatalytic reaction mechanism were also detected. Results show that high-quality heterojunction and optimum structure ratios have vital influence on photocatalytic performance, there is an obvious synergetic effect between anatase and TiO2-B structure, degradation reactions on methyl orange (MO) under ultraviolet light irradiation prove that the highest activity toward MO removal can be obtained for material with 82.5% anatase structure.