Lianjie Zhu

Title : Designable synthesis of TiO2 nanostructures/composites and photocatalytic applications

Abstract:

TiO2 is a promising photocatalyst for H2 production and photodegradation of organic dyes. The photocatalytic activity of the TiO2 nanomaterial is closely related to its structure and composition. Thus, tuning its structure and composition is significant to enhance photocatalytic activity of the TiO2 nanomaterials. Series of TiO2 nanomaterials have been designed and synthesized, including well aligned Ti3+, N co-doped TiO2 nanotube array (NTA) films, Pd (or Au/Ag) loading TiO2 NTAs, TiO2 hollow spheres, Pd-CQDs co-decorated TiO2 nanosheets, Pd-cations co-modified TiO2 nanosheets, sulfide modified TiO2 composites. They exhibited excellent photocatalytic H2 productions and photodegradations on organic dyes. The influencing factors to activities have been explored and the photocatalytic reaction mechanisms have been proposed and discussed. The results show that the hydrogen evolution rate (HER) over the Pd-CQDs co-loading TiO2 nanosheets could be 901 times higher than that of the pure TiO2, which could be attributed to the synergistic effect of Pd and CQDs. Introducing small amount of alkali salt (0.5 g L?1) solution in the preparation process of the TiO2 or in the photocatalytic reaction medium (1 g L?1) can also increase the HER rates distinctly.

Audeince Take Away:

• Series of TiO2 nanostructures and composites have been designed and prepared. A few strategies were discussed to increase the photoctalytic activities (H2 production and photodegradation of dyes) of the TiO2 nanomaterials
• The TiO2 NTAs film catalyst is easy to be reclaimed from the dye solution after photo-degradation reactions, which is meaningful for practice application
• CQD was found helpful to photoreduction of Pd2+ to Pd metal nanoparticles on the TiO2, which is beneficial to enhancement of photocatalytic H2 production efficiency on the TiO2 composites and the utilization rate of Pd source. This may offer an idea to designer for synthesis of more efficient photocatalysts
• Ti3+,N co-doping, metal cation doping, noble metal loading, sulfide co-catalysts can all enhance the photocatalytic activities of the TiO2 nanomaterials to different extent. To maximize the activity, more than one strategy may be taken according to requirement

Biography:

Prof. Dr. Zhu received her BSc. and MSc. degrees at Jilin University in 1994 and 2001, respectively. She gained her doctorate in physical chemistry at the Delft University of Technology (Netherlands) in 2005. As a post doctorate, she joined the Chemistry Institute of the University of Copenhagen in 2006. Since 2007, she worked in Tianjin University of Technology, where she obtained a professor position in 2013. Her current research interest is functional nanomaterials for photocatalysis, gas sensing and antibacterial. She has published more than 50 research articles in SCI(E) journals that were cited more than 1000 times.