Dual Functions of CO_2 Molecular Activation and 4f Levels as Electron Transport Bridge in Dysprosium Single Atom Composite Photocatalysts with Enhanced Visible-Light Photoactivities

摘要

The effect of rare earth (RE) single atoms on photocatalytic activity is very complex due to its special electronic configuration, which leads to few reports on the RE single atoms. Here, Dy3+ single atom composite photocatalysts are successfully constructed based on both the special role of Dy3+ and the special advantages of CdS/g-C3N4 heterojunction in the field of photocatalysis. The results show that an efficient way of electron transfer is provided to promote charge separation, and the dual functions of CO2 molecular activation of rare-earth single atom and 4f levels as electron transport bridge are fully exploited. It is exciting that under visible-light irradiation, the catalytic performance of CdS:Dy3+/g-C3N4 is approximate to 6.9 times higher than that of pure g-C3N4. The catalytic performance of CdS:Dy3+ and CdS:Dy3+/g-C3N4 are approximate to 7 and approximate to 13.7 times higher than those of pure CdS, respectively. Besides, not all RE ions are suitable for charge transfer bridges, which is not only related to the 4f levels of RE ions but also related to the bandgap structure of CdS and g-C3N4. The pattern of combining single-atom catalysis and heterojunction opens up new methods for enhancing photocatalytic activity.