Platinum Nanoparticles with Low Content and High Dispersion over Exfoliated Layered Double Hydroxide for Photocatalytic CO2 Reduction

In this study, improving the dispersion of Pt nanoparticles (Pt NPs) was proposed to reduce the quantity of noble metal cocatalyst in a CO2 photocatalytic reaction. A low content of Pt NPs was loaded over ex-foliated layered double hydroxide (exLDH) by electrostatic interaction for the preparation of a highly dispersed Pt-loaded photocatalyst. Transmission electron microscopy (TEM) images indicate that Pt/ex-LDH shows a better dispersion of Pt NPs compared with Pt-loaded initial LDH. Experimental results show that 0.1% Pt-loaded ex-LDH shows the highest photocatalytic activity with a CO evolution rate of 2.64 mu molg(-1) h(-1), which is about 8.52 and 2.20 times higher than those of 1% Pt-loaded ex-LDH and 0.1% Pt-loaded initial LDH. Characterization results show that the high photocatalytic activity of 0.1% Pt-loaded ex-LDH originates from the enhanced charge separation efficiency by highly dispersed Pt NPs and the combination center caused by a high content of Pt species accounts for the decrease of photocatalytic activity when the Pt content is high.

Automated summary

Adding a low content of Pt nanoparticles onto exfoliated layered double hydroxide results in a highly dispersed Pt-loaded photocatalyst with improved photocatalytic activity. The enhanced charge separation efficiency by the highly dispersed Pt nanoparticles contributes to the high photocatalytic activity observed. Additionally, a decrease in photocatalytic activity is noted at higher Pt content due to the formation of a combination center from the high Pt species concentration.