Direct Z-scheme photocatalyst 

Jiaguo Yu

State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology

Abstract: Direct Z-scheme photocatalysts, imitating photosynthesis of leaves, is recognized as a feasible solution for enhancing photocatalytic efficiency. In 2013, we proposed a new concept of “direct Z-scheme photocatalyst” to interpret the improvement in formaldehyde degradation by TiO2/C3N4. This configuration is quite similar to that of traditional Type-II, as illustrated in Figure 1a and 1b. Nevertheless, the transfer mechanism of photogenerated charge carriers is distinct from that of Type II heterojunction. As for direct Z-scheme, the redox potential of the semiconductors can be optimized. The electrons from SC B and holes from SC A are recombined. Then the reduction reaction and oxidation reaction are carried out on the photocatalyst with highest conduction band (CB) potential and on the photocatalyst with lower valence band (VB) potential, respectively. In virtue of the Coulomb attraction rather than repulsion between the electrons in SC B and holes in SC A, theoretically, the charge transfer in direct Z-scheme is much easier than that in traditional Type-II heterojunction. Ever since our initiative in 2013, enormous results on direct Z-scheme photocatalysts have been reported.

Figure 1. Comparison of the charge carrier separation mechanism on the (a) type-II heterojunction and (b) direct Z-scheme photocatalyst built on two different semiconductors (SCs).

Biography: Jiaguo Yu received his BS and MS in chemistry from Central China Normal University and Xi’an Jiaotong University, respectively, and his PhD in Materials Science in 2000 from Wuhan University of Technology. In 2000, he became a Professor at Wuhan University of Technology. He was a postdoctoral fellow at the Chinese University of Hong Kong from 2001 to 2004, a visiting scientist from 2005 to 2006 at University of Bristol, a visiting scholar from 2007 to 2008 at University of Texas at Austin. His current research interests include semiconductor photocatalysis, photocatalytic hydrogen production, CO2 reduction to hydrocarbon fuels, and so on. See more details on: