A cation exchange strategy to construct Rod-shell CdS/Cu2S nanostructures for broad spectrum photocatalytic hydrogen production

Herein, Cu2S as the outer shell is grown on CdS nanorods (NRs) to construct rod-shell nanostructures (CdS/Cu2S) by a rapid, scalable and facile cation exchange reaction. The CdS NRs are firstly synthesized by a hydrothermal route, in which thiourea as the precursor of sulfur and ethylenediamine (EDA) as the solvent. And then, the outer shells of CdS NRs are successfully exchanged by Cu2S via a cation exchange reaction. The obtained CdS/Cu2S rod-shell NRs exhibit much enhanced activity of hydrogen production (640.95 mu mol h(-1) g(-1)) in comparison with pure CdS NRs (74.1 mu mol h(-1) g(-1)) and pure Cu2S NRs (0 mu mol h(-1) g(-1)). The enhanced photocatalytic activity of CdS/Cu2S rod-shell NRs owns to the following points: i) the photogenerated electrons generated by CdS quickly migrate to Cu2S without any barrier due to rod-shell structure by the in-situ cation exchange reaction, a decreased carrier recombination is achieved; ii) Cu2S as outer shells broaden the light absorption range of CdS/Cu2S rod-shell NRs into visible or even NIR light, which can produce more electrons and holes. This work inspires people to further study the rod-shell structured photocatalyst through the cation exchange strategy to further solar energy conversion. (C) 2021 Elsevier Inc. All rights reserved.

Automated summary

In this study, rod-shell nanostructures (CdS/Cu2S) were constructed by growing Cu2S as the outer shell on CdS nanorods, resulting in significantly enhanced hydrogen production activity. The improved photocatalytic performance of CdS/Cu2S rod-shell nanostructures is attributed to the structural design facilitating electron transfer and the broadened light absorption range achieved by Cu2S outer shells. This work provides insight into the design of rod-shell structured photocatalysts for efficient solar energy conversion.