报告内容摘要

A series of nanostructured TiO2 sensors and photoelectrochemical cells have been developed in our group for photoelectrochemical determination of organic compounds, leading to a series of commercialized patents and commercial products. This sensing mechanism is based on photoelectrocatalytic oxidation of organic compounds in waters under UV radiation. Recently, conventional hydrogenation process (5% H2 in 1 bar Ar, 400°C) was adopted to treat nanostructured TiO2 photoanodes e.g., TiO2 nanorod arrays (TNRs) and TiO2 nanotubes (TNTs) electrodes. Our preliminary results suggests that hydrogenation is an efficient and effective means to extend light absorption to visible light region and improve electron conductivity of TiO2 via introduction of oxygen vacancy and mid-gap levels in TiO2 lattice. The hydrogenated TiO2 electrodes show promising potential in sensing organic compounds in water.

An enhanced hydrogenation process (40 bar, 450°C) was used to white Li4Ti5O12 and rutile precursors and subsequently blue Li4Ti5O12 and blue rutile TiO2 nanoparticles were obtained. Material characterisation results indicate no significant changes in morphology and unit cell of the anode materials, but significant increment of conductivity and the formation of oxygen vacancy (Ti+3) throughout the lattice. In comparison with the white Li4Ti5O12 and TiO2 based LIBs, the hydrogenated samples based LIBs shows higher capacity, better rate performance and longer operational stability. These major enhancements are not only resulted from the increase of electronic conductivity due to the formation of oxygen vacancy throughout crystalline lattice, but also from faster lithium-ion mass transport at the surface and within the crystalline lattice.

In conclusion, the hydrogenation processes can be further developed as facile method to improve the performance of sensing and energy storage devices.

报告人简介

A/Prof. Shanqing Zhang obtained his PhD degree in electrochemistry in 2001 at Griffith University, Australia. Since then, he has been working on synthesis, modification, characterisation of nanostructured materials for sensing, energy conversion and energy storage devices. As a core inventor, Dr. Zhang has developed a series of patented and commercialized nanotechnologies for environmental monitoring based on the functional nanomaterials. He was awarded Australia Research Council Future Fellow in photoelectrocatalysis for 2009-2013. Currently, Dr. Zhang is leading his group conducting research on synthesis of functional nanomaterials and functionalization of natural polymers for lithium ion batteries, sodium ion batteries and supercapacitors.

Centre for Clean Environment and Energy, Griffith School of Environment, Gold Coast Campus, Griffith University, QLD 4222, Australia