Near-infrared-activated NaYF4:Yb3+, Er3+/Au/CdS for H2 production via photoreforming of bio-ethanol: plasmonic Au as light nanoantenna, energy relay, electron sink and co-catalyst

Abstract

A sandwich-structured NaYF₄:Yb³⁺, Er³⁺/Au/CdS architecture, as an up-conversion-involved photocatalyst for H₂ production through photoreforming of renewable bio-ethanol, was constructed successfully. The Au nanoparticles embedded in the NaYF₄:Yb³⁺, Er³⁺/CdS interface play a quadruplex role to improve the solar utilization efficiency. First, plasmonic Au works as a light nanoantenna to harvest more incident light. Second, plasmonic Au acts as an energy relay, in which Au SPR-induced Förster resonance energy transfer (FRET) and plasmonic resonance energy transfer (PRET) synergistically facilitate the energy transfer from NaYF₄:Yb³⁺, Er³⁺ to Au to CdS. Third, Au acts as an electron sink to promote electron–hole separation. Lastly, Au serves as a co-catalyst to activate H₂ evolution from bio-ethanol. The multifunctional Au makes NaYF₄:Yb³⁺, Er³⁺/Au/CdS exhibit enhanced NIR-driven photocatalytic bio-ethanol reforming activity. Moreover, NaYF₄:Yb³⁺, Er³⁺/Au/CdS shows superior photoactivity under simulated sunlight. This unique fabrication has implications for the rational design of highly efficient solar-energy-harvesting devices.