Improved photocatalytic activity of TiO2 produced by an alcohothermal approach through in-situ decomposition of NH4HCO3

High crystallinity of TiO2 was prepared by a modified alcohothermal method, in which titanium isopropoxide was used as the titania precursor, absolute ethanol as the reaction medium, and NH4HCO3 as the raw materials for release of water, ammonia and carbon dioxides via in-situ decomposition. The X-ray powder diffraction (XRD) and transmission electron microscope (TEM) measurements showed that water and ammonia from the in-situ decomposition of NH4HCO3 played an important role in conducting the size, shape, crystallinity and microstructure of TiO2. The photoluminescence spectroscopy and photocurrent measurements indicated that enhanced crystallinity could hinder the recombination and promote the separation of electron-hole pairs in TiO2, which contribute to the improvement of photocatalytic activity. Methyl orange photodegradation under UV light confirmed that high crystallinity of TiO2 did present a high photocatalytic activity due to the effective separation of photoinduced charges.

With the introduction of NH4HCO3 during alcohothermal process, photocatalytic performance of TiO2 is significantly enhanced due to the increased crystallinity. When the added NH4HCO3 is up to 3 g, TiO2-N3 exhibits the best photocatalytic activity. Figure optionsDownload as PowerPoint slide