Cu nanoparticles were deposited on the surface of commercial TiO nanoparticles (Cu-TiO) using different methods aiming at the production of highly efficient visible light photocatalysts. Photocatalytic H evolution rates obtained from methanol/water mixtures revealed no significant influence of the presence of copper oxides on the photoreaction upon visible light illumination. The photocatalytic H production rates were evaluated upon illumination with different spectral ranges (≥420 nm or ≥500 nm) and the results evidenced that the visible light induced charge carrier formation on the Cu-TiO photocatalysts consists of two distinct pathways: the direct excitation of TiO and the induced excitation by the so-called surface plasmon resonance (SPR) effect of the Cu nanoparticles on the TiO surface. Both pathways are present when the full visible range of the spectrum is used (≥420 nm), while for illumination at longer wavelengths (≥500 nm), the photocatalytic activity is solely promoted by the Cu-SPR effect. Electron paramagnetic resonance (EPR) and laser flash photolysis measurements were performed to clarify the underlying mechanism of Cu-TiO photocatalysts upon visible light illumination.

The Surface Plasmon Resonance (SPR) driven photocatalytic H2 production upon visible light illumination (≥500 nm) was investigated on gold-loaded TiO2 (Au–TiO2).

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