The effects of localized surface plasmon resonance on Cu2− x S as a full-spectrum-response photocatalyst

Degenerate semiconductors have many unique electronic structures and optical properties which give them the potential to produce localized surface plasmon resonance (LSPR). Non-stoichiometric Cu2− x S compounds have attracted much interest as photocatalysts. What kind of interesting phenomena will occur when the above aspects are combined? In order to examine this idea, in the present work the LSPR effects of Cu2− x S compounds as degenerate semiconductors and their application in the field of photocatalysis were systematically studied by combining density functional theory calculations, finite-difference time-domain simulations, and experimental preparation and characteristics. It was confirmed that the non-stoichiometric Cu2− x S compound is a typical degenerate semiconductor. The degenerate states of Cu2− x S directly lead to LSPR effects, which can be controlled by the non-stoichiometry and particle size of the Cu2− x S compounds. The enhanced photocatalytic activity of the LSPR effects was evaluated by degrading organic pollutants, revealing that LSPR effects can enable Cu2− x S to achieve photocatalytic degradation of organic pollutants driven by full-spectral irradiation. These findings suggest that further research and development on degenerate semiconductors as novel photocatalysts is worthwhile.