Heavily doped semiconductors such as Cu_2-xSe have demonstrated significant surface plasmon resonance (SPR) primarily in the NIR region.^[1,2] For solar fuel generation, the effective use of NIR spectrum has been limited although it accounts for over 50% of the solar radiation. In this work, we demonstrated the tunable NIR SPR absorption for Cu_2-xSe nanorods with various aspect ratios. The samples were prepared by directly inserting Cu⁺ ions into Se nanorods during the ion exchange process.^[3] With the distinctive NIR SPR absorption, the Cu_2-xSe nanorods exhibited remarkable photocatalytic activity toward hydrogen production. This demonstration suggests a possibility to further extend the utilization of solar spectrum toward near IR region, an important merit for advanced photocatalytic and photoelectrochemical applications.

References

[1] A. Comin, L. Manna, Chem. Soc. Rev., 2014, 43, 3957-3975.

[2] J. Kim, A. Agrawal, F. Krieg, A. Bergerud, D. J. Milliron, Nano Lett., 2016, 16, 3879-3884.

[3] M.-Y. Chen, Y.-J. Hsu, Nanoscale, 2013, 5, 363-368.