Prof. Yujie Xiong’s group cooperated with Prof. Jun Jiang in Prof. Yi Luo’s research team and Prof. Qun Zhang in the fields of materials design and synthesis, theoretical simulation, and advanced characterization, and made great progress on hydrogen production and photochemical water splitting. They proposed a practical strategy to facilitate the migration of holes in semiconductor (the low rate of which limits photocatalytic efficiency) by taking advantage of the Schottky barrier between p-type semiconductor and metal. Their results was recently published on Angew. Chem. Int. Ed. (http://dx.doi.org/10.1002/anie.201310635). Mr. Lili Wang and Ms. Jing Ge, Ph.D students in the group, are the co-author of the paper.

Both the Schottky barrier and charge spatial distribution are critical elements to the electron–hole separation and charge accumulation at surface, and highly dependent on semiconductor facets in a semiconductor–metal configuration. As demonstrated in their Cu2O-Pd model system, these two effects can be reconciled in a single-faceted configuration by taking advantage of high work function of semiconductor surface. To achieve better efficiency, the establishment of the Schottky barrier has to be prioritized by selecting an appropriate surface facet for metal deposition and charge migration sites, and meanwhile the photoexcited electrons should be allowed to migrate out from this facet by virtue of the charge spatial distribution. Moreover, the density of metal deposition definitely holds the key to suppressing potential electron–hole recombination, as both the electrons and holes are accumulated on the same surface. With this design optimized, the charge migration rates can be better harnessed. Given that the mobility of holes limits to a large extent the efficiency of various photocatalytic reactions, it is anticipated that this work casts new light on photo-catalysts design in consideration of facet effect.