iChEM researchers, Prof. Yi Xie’s group and Prof. Qun Zhang from Prof.Yi Luo’s group made an important progress in the area of photoelectrocatalysis, which reveals the effect of doping in the scale of atoms. (Angew. Chem. DOI: 10.1002/anie.201503410)

Photocatalysis hydrogen evolution reaction has the potential for environment friendly energy, while the low effectiveness of the catalyst hinders its application. Although researchers show doping different element can mediate the electron structure in semiconductors, however, the mechanism of doping is still undercover. Probably, the former researchers doped the elements inside the semiconductor instead of surface which is appropriate for catalysis.

Prof. Yi Xie’s group designed atomic thick slices by confinement doping as a model system to study doping mechanism. A model of doping confined in atomic layers is proposed for atomic-level insights into the effect of doping on photocatalysis. Co-doping confined in three atomic layers of In2S3 was implemented with a lamellar hybrid intermediate strategy. Density functional calculations reveal that the introduction of Co ions brings about several new energy levels and increased the density of states at the conduction band minimum, leading to sharply increased visible-light absorption and three times higher carrier concentration.

Co-operated with Prof. Qun Zhang, ultrafast transient absorption spectroscopy reveals that the electron transfer time of about 1.6 ps from the valence band to newly formed localized states is due to co-doping. The 25-fold increase in average recovery lifetime is believed to be responsible for the increased electron–hole separation.