Design of multicomponent aerogels and their performance in photocatalytic hydrogen production

Abstract

Multicomponent aerogels were prepared from the preformed components (i) crystalline TiO2 nanoparticles, (ii) Pt nanoparticles as well as (iii) multilayer reduced graphene oxide (m-rGO) and were subsequently tested for photocatalytic H2 evolution. The multicomponent photocatalysts showed a 3D architecture consisting of crosslinked TiO2 nanoparticles which are decorated with (1–2nm) platinum nanoparticles with embedded m-rGO. The three-component materials retained the mesoporosity and high surface area of pure TiO2 aerogels, as illustrated by transmission electron microscopy and nitrogen sorption experiments. This architecture is responsible for the enhancement of the photocatalytic activity, which reached a maximum hydrogen production rate of 11.61mmolH2g−1h−1 for the TiO2 aerogel with a cocatalyst content of 0.4wt% Pt. In comparison, a Pt/TiO2 reference powder produced only about 3.28mmolH2g−1h−1. In this way, the aerogel architecture enables the design of compositions other than Pt/TiO2 or even the co-assembly of further active materials such as conducting components into the aerogel matrix as shown by the addition of m-rGO to the Pt/TiO2 aerogels.