Enhancement of Solar Hydrogen Generation by Synergistic Interaction of La2Ti2O7 Photocatalyst with Plasmonic Gold Nanoparticles and Reduced Graphene Oxide Nanosheets

This report shows that incorporating nitrogen-doped La2Ti2O7 (NLTO) photocatalyst with gold nanoparticles and reduced graphene oxide (rGO) nanosheets improves the photocatalytic hydrogen generation rate significantly. The underlying mechanism of the photocatalysis enhancement by the presence of the Au nanoparticles and the rGO nanosheets is revealed. Nitrogen doping alone can extend the light absorption range of photocatalyst to 550 nm. In addition, nitrogen doping has enabled plasmon-induced resonance energy transfer (PIRET) from the plasmonic Au nanoparticle to NLTO, inducing charge separation in NLTO solar radiation up to 600 nm. The Au nanoparticles not only serve as the photosensitizers but also lead to a shift in the flat band potential, suppressing the charge recombination and improving the charge extraction. The rGO does not affect the charge separation process but significantly increases the lifetime of photogenerated charge carriers.