Enhanced core-shell CeO:Er,Yb@WO heterojunction H generation by multiband emissions of Er ions.

The core-shell CeO:Er,Yb@WO heterojunction is successfully synthesized via the facile solvothermal method. The octahedral CeO:Er,Yb nanocrystal's core exhibits green (H, S → I), red (F → I) and NIR (I → I and I → I) emission under 980 nm laser diode excitation, and the multiband emissions are absorbed by the WO nanowire's shell, re-exciting its higher energy localized surface plasmon resonances (LSPR). With the excitation of 980 nm, the photocatalytic property of CeO:Er,Yb@WO for hydrogen (H) evolution from ammonia borane (BHNH), a three-fold increase compared to WO, is researched. The application of natural sunlight for the production of H is studied, and an obvious H production enhancement compared to the use of WO (two-fold) is also observed. This remarkable enhancement in the catalytic activity of CeO:Er,Yb@WO heterostructures is ascribed to the re-excitation of LSPR by multiband emissions of CeO:Er,Yb.