Wuhan University of Technology

About: Wuhan University of Technology is a education organization based out in Wuhan, China. It is known for research contribution in the topics: Microstructure & Catalysis. The organization has 40384 authors who have published 36724 publications receiving 575695 citations. The organization is also known as: WUT.

Tuning the relative concentration ratio of bulk defects to surface defects in TiO2 nanocrystals leads to high photocatalytic efficiency.

Abstract: TiO2 nanocrystals with tunable bulk/surface defects were synthesized and characterized with TEM, XRD, BET, positron annihilation, and photocurrent measurements. The effect of defects on photocatalytic activity was studied. It was found for the first time that decreasing the relative concentration ratio of bulk defects to surface defects in TiO2 nanocrystals could significantly improve the separation efficiency of photogenerated electrons and holes, thus significantly enhancing the photocatalytic efficiency.

New understanding of the difference of photocatalytic activity among anatase, rutile and brookite TiO2

Abstract: In general, anatase TiO2 exhibits higher photocatalytic activities than rutile TiO2. However, the reasons for the differences in photocatalytic activity between anatase and rutile are still being debated. In this work, the band structure, density of states, and effective mass of photogenerated charge carriers for anatase, rutile and brookite TiO2 are investigated by the first-principle density functional theory calculation. The results indicate that anatase appears to be an indirect band gap semiconductor, while rutile and brookite belong to the direct band gap semiconductor category. Indirect band gap anatase exhibits a longer lifetime of photoexcited electrons and holes than direct band gap rutile and brookite because the direct transitions of photogenerated electrons from the conduction band (CB) to valence band (VB) of anatase TiO2 is impossible. Furthermore, anatase has the lightest average effective mass of photogenerated electrons and holes as compared to rutile and brookite. The lightest effective mass suggests the fastest migration of photogenerated electrons and holes from the interior to surface of anatase TiO2 particle, thus resulting in the lowest recombination rate of photogenerated charge carriers within anatase TiO2. Therefore, it is not surprising that anatase usually shows a higher photocatalytic activity than rutile and brookite. This investigation will provide some new insight into understanding the difference of photocatalytic activity among anatase, rutile and brookite.

A Review of Direct Z-Scheme Photocatalysts

Abstract: Recently, great attention has been paid to fabricating direct Z-scheme photocatalysts for solar-energy conversion due to their effectiveness for spatially separating photogenerated electron–hole pairs and optimizing the reduction and oxidation ability of the photocatalytic system. Here, the historical development of the Z-scheme photocatalytic system is summarized, from its first generation (liquid-phase Z-scheme photocatalytic system) to its current third generation (direct Z-scheme photocatalyst). The advantages of direct Z-scheme photocatalysts are also discussed against their predecessors, including conventional heterojunction, liquid-phase Z-scheme, and all-solid-state (ASS) Z-scheme photocatalytic systems. Furthermore, characterization methods and applications of direct Z-scheme photocatalysts are also summarized. Finally, conclusions and perspectives on the challenges of this emerging research direction are presented. Insights and up-to-date information are provided to give the scientific community the ability to fully explore the potential of direct Z-scheme photocatalysts in renewable energy production and environmental remediation.