Plasmonic gold particle generation in layer-by-layer 2D titania films as an effective immobilization strategy of composite photocatalytsts for hydrogen generation

We propose a strategy for the surface immobilization of composite catalysts consisting of titania nanosheets (TNs) and Au nanoparticles (AuNPs) via the in situ generation of nanoparticles in a covalent LbL (Layer-by-layer) matrix followed by calcination. The thickness and compactness of the TNs and polymer film were finely adjusted to prepare AuNPs of varying sizes and densities, leading to surface immobilized composite catalysts with varying H2 generating capacities after calcination. The optimized composite catalyst with the addition of 2.5 wt% Pt as cocatalyst presented high performance even comparable to the highest hydrogen generation efficiency by mobilizing particle catalysts containing TNs. The study demonstrates that a proper surface immobilization strategy not only facilitates catalysts application and collection, but also allows for catalytic efficiency to be enhanced by fine tuning the ratios and structures of each of the constituent components.