Platinum Nanoparticles with Low Content and High Dispersion over Exfoliated Layered Double Hydroxide for Photocatalytic CO<sub>2</sub> Reduction
Jie Xu, Xiaowei Liu, Zijian Zhou, Lidan Deng, Lei Liu, Minghou Xu
Abstract
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 exfoliated layered double hydroxide (ex-LDH) 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 μmolg–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.